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Analyzing Historic Masonry Wall Performance

Wilmer-Davis Hall is a residential complex on the Washington State University (WSU) Pullman campus. Built in 1937 by Architect Stanly Smith, with John Maloney, the six-story structure is composed of masonry and concrete with a masonry/brick veneer in the classical and Georgian Revival architectural styles. For a recent feasibility study of the complex, PMA provided an exterior assessment and a limited moisture study utilizing Wärme Und Feuchte Instationär (WUFI), an industry standard application in predicting wall performance to determine how additional insulation may impact the existing constructions and wall performance.

The primary concerns of this analysis included increased potential for freeze thaw action and increased mold growth as a result of added insulation. When historic buildings are insulated the insulation is typically added to the interior of the structure to prevent alterations to the exterior appearance. This often causes the outer layers of the wall to be both colder and wetter as the materials are no longer warmed and dried by the interior heating system. The additional water and more extreme temperatures can result in an increase in freeze thaw action, corrosion of metal reinforcement, and/or increased mold growth.

Additionally adding insulation to a wall changes the location of the dew point within that construction (the point at which vapor in the air condenses into water). A dew point within the middle of the wall can also result in increased moisture within the wall cavity. If a wall has difficulties drying due to any of the above causes it is possible that over the course of several years the quantity of water within the wall will consistently increase. Accumulation of water will exacerbate reinforcement corrosion and mold growth and can result in increased freeze thaw action. This study focused on the following metrics to analyze proposed wall performance: quantity of water in the assembly, quantity of water in each material layer, relative humidity in layers susceptible to mold growth, and isopleths.

MODEL SETUP
As in any simulation analysis a number of assumptions were made regarding the existing wall construction and the proposed design conditions. A variety of different conditions were analyzed in order to explore the range of conditions and variables. Below is a description of the inputs as well as an analysis of the results.

Four (4) proposed wall constructions were analyzed to determine how different types, quantities, and configurations of insulation would impact the existing constructions. The configurations were based on outlined solutions for meeting Washington State Energy Code (WSEC) or providing improved thermal comfort. Two of the proposed constructions meet WSEC (Option 1 and Option 2), while two of the solutions (Option A and Option B) fall short of fully meeting WSEC, but would provide improved insulation values. The options simulated included:

Base Case (Existing Conditions) (R-4.8)
3-1/2” Masonry
1” Air Gap
7-1/2” Hollow Clay Tile Back-Up Wall
1-1/2” Plaster

Option 1 (Meets WSEC) (R-15.4, continuous insulation)
3-1/2” Masonry
1” Air Gap
7-1/2” Hollow Clay Tile Back-Up Wall
1-1/2” Plaster
2” Expanded Polystyrene
Vapor Retarder (1perm)
0” Gypsum

Option 2 (Meets WSEC) (R-20.9, insulation is not continuous)
3-1/2” Masonry
1” Air Gap
7-1/2” Hollow Clay Tile Back-Up Wall
1-1/2” Plaster
3” Batt Insulation
0-1/2” Expanded Polystyrene
Vapor Retarder (1perm)
0-5/8” Gypsum

Option A (R 17.4, insulation is not continuous)
3-1/2” Masonry
1” Air Gap
7-1/2” Hollow Clay Tile Back-Up Wall
1-1/2 Plaster
2” Foamed-In-Place Polyurethane
Vapor Retarder (1perm)
0-5/8” Gypsum

Option B (R-18.4, insulation is not continuous)
3-1/2” Masonry
1” Air Gap
7-1/2” Hollow Clay Tile Back-Up Wall
1-1/2” Plaster
3-1/2” Batt Insulation
Vapor Retarder (1perm)
0-5/8” Gypsum

Materials It should be noted that no material testing was performed during this phase of the project – instead default material properties were chosen from the WUFI database. Materials used include:

  • Masonry: The material ‘Brick (Old)’ was used to simulate the existing masonry. The material is a generic historic brick material compiled from a variety of different bricks and included in the WUFI database.
  • Airspaces: All airspaces were modeled without additional moisture capacity which according to WUFI, models more realistic moisture storage in air cavities.
  • Hollow Clay Tile: The historic drawings indicate that behind the masonry is hollow clay tile. WUFI does not have a default material for hollow clay tile. Instead a masonry material ‘Red Matt Clay Brick’ was used to represent the solid portions of the clay tile. Air spaces were used to simulate the hollow portions of the tile.
  • Historic Plaster: The WUFI database does not have a default historic plaster material. The ‘Regular Lime Stucco’ material was used to simulate the existing plaster.
  • Batt Insulation: ‘Low Density Glass Fiber Batt Insulation’ was used in simulations.
  • Rigid Insulation/Expanded Polystrene: ‘Expanded Polystyrene’ was used in simulations.
  • Fomed-In-Place: ‘Sprayed Polyurethane Closed-Cell’ was used in simulations
  • Gypsum: ‘Interior Gypsum Board’ was used in simulations.


  • Weather/Interior Conditions In each simulation the model was set to mimic extreme situations to verify that the existing walls will perform in all conditions. The Spokane, Washington weather file indicates that the south elevation should have the most wind driven rain and moisture impacting the wall. Given this information the analysis used south exposure and the Spokane weather file to simulate exterior conditions. For the interior climate conditions the following profiles were used:

  • Interior temperatures ranging from 69 °F to 72 °F
  • Relative humidity ranging from 50% – 60%


  • The above values represent a relatively high moisture load which is consistent with the existing use as a residential facility.

    Water Intrusion Additionally as per ASHRAE 160 a small leak (1% of driving rain) was introduced into the exterior assembly to simulation a scenario where water was penetrating the exterior surface. This could occur at bondline failures in the mortar or penetrations through the wall assembly. The leak was placed past the masonry veneer on the face of the hollow clay tile backup wall.

    Initial Conditions Lastly the initial conditions of the materials were determined using ASHRAE 160. For existing wall materials EMC80 was used as the initial moisture content. (EMC80 is a value expressing an equilibrium of water and material masses at 80% humidity). For new components the expectation was that the materials would be installed from the interior and would remain dry during the construction process – thus EMC80 was used for new components as well.

    WUFI RESULTS
    Four metrics were used to interpret and analyze the following WUFI results: Total Water Content/Water Content in Material Layers, Temperature, Relative Humidity, and Isopleths.

    Total-Water-Contents-WSU-Wilmer-Davis-WUFI-Report-6Total Water Content WUFI can predict the total accumulation of water over the time frame of the simulation, in this case five years. Over the course of each year a wall assembly will be wetted by the rain, and dry over the summer months. Differences in humidity and temperature between spaces may cause water condensation within the walls. If conditions do not allow condensation or other water to dry, materials may accumulate water over a period of time.

    The chart above shows how each of the different simulations performed. Note that total water content is measured per ft2 of wall. Walls that are thinner (existing construction) will inherently have less capacity to hold water. In general all of the walls performed in a similar manner – an indication that the retrofit strategies should perform in a comparable manner when compared to the existing walls. As can be seen in the chart, all of the simulations, including the base case showed some accumulation of water over the five year simulation. These results, however, do not conclusively show that the proposed walls will accumulate water. The results indicate that even the base case is accumulating water over time. During PMA’s site visit, however, the existing exterior walls appeared to be performing well – which would not be the case if they were consistently accumulating water. Additional analysis showed that the gradual accumulation of Total Water Content appears to be a result of initial instability within the wall construction that equalizes over time. A 20 year simulation showed accumulation over the first five years, after which the water content stabilizes.

    Water Content in Material Layers Each of the individual layers of material in a wall assembly have the capacity to hold and retain water. A high water content in any individual layer can indicate the potential for mold growth, the possibility for damage associated with freeze thaw, and a reduction in R-Value based on moisture content. Mold growth is possible when the moisture content is above 20% and if the material has the capacity to feed mold growth. The charts below show how each simulation performed for each layer within the wall.

    Water-Content-Materials-WSU-Wilmer-Davis-WUFI-ReportIn general most layers remained well below the 20% threshold for mold growth. The insulation layers, however, are an exception. Options 2 and B both had batt and/or foam insulation which yearly exceeded 20% water. This quantity of water is somewhat concerning for the batt insulation as it may reduce the material’s R-Value and/or contribute to mold growth depending on the composition of the material. Solutions that used foam insulation performed better than those with batt insulation.

    Temperature One common result of insulating a historic building from the interior is increased freeze thaw action. Insulation prevents the interior conditioned space from heating and drying the exterior masonry. As a result the masonry is typically saturated with more water and exposed to colder temperatures. The analysis looked at the temperature within the middle of the masonry to determine how added insulation would impact the material. A chart comparing the base case to the four options for insulation is located below. As can be seen the brick temperature remains consistent with the base case in all retrofit options. This is an indication that the masonry may not by exposed to additional weathering as a result of added interior insulation. It should be noted that not all masonry reacts to water saturation and freezing conditions in the same manner. To further analyze the masonry’s susceptibility to freeze-thaw action lab analysis is recommended to determine material performance. If results indicate that the masonry is susceptible to freeze-thaw it will be critical to ensure new constructions do not lead to a significantly colder/wetter exterior wall.

    Relative Humidity The relative humidity of the air within the wall construction also has an impact on material longevity and mold potential. A high relative humidity in plaster or batt insulation layers may indicate mold growth, while a high relative humidity in layers with reinforcement may indicate the potential for corrosion. A constant and high relative humidity (above 80%) indicates the potential for mold growth. The charts to the right focus on several susceptible layers, the existing plaster, batt insulation, and gypsum board. In general the majority of the layers susceptible to mold remained below 80% relative humidity, or consistently dropped below 80% relative humidity allowing the material to periodically dry. An exception was the existing plaster layer. The addition of interior insulation caused the relative humidity within the layer to increase approximately 15%, from 65% (base case) to just over 80% (all options for added insulation). This spike in relative humidity is concerning and could indicate the potential for mold growth within the layer.
    Materials-Temperature-Relative-Humidity-WSU-Wilmer-Davis-WUFI-Report
    Isopleths WUFI can also predict mold growth by plotting isopleths on the interior surface. The isopleths are plots of the temperature and the relative humidity for every time period calculation. When the temperature and relative humidity both exceed the limiting lines calculated by WUFI there is the potential for mold growth. The simulations indicate that there is very little potential for mold growth. All of the simulations begin above the limiting lines, but over time equalize and remain well below the threshold calculated by WUFI.
    wufi-isopleths-results-wsu
    CONCLUSIONS
    The results described above indicate that there could be some challenges to designing an appropriate insulation system for Wilmer Davis Hall. Three of the primary concerns noted in the above analysis are: increasing total water content quantities; high quantities of water in the batt insulation layers; and consistently high relative humidity’s in the existing plaster layer.

    In general Option 1 and Option A performed better than Option 2 and Option B – primarily because they relied on only foam/rigid insulation. This resulted in no risk of mold growth within the insulation layers and no reduction of the R-Value. Concerns were still identified with both Options in terms of total water content and relative humidity in the plaster layer.

    Prior to detailing a new wall for construction additional analysis is recommended. Minor changes in material properties can have significant impacts on wall performance. The above analysis has indicated that there is a potential for mold growth, but has not confirmed its likelihood. Most of the metrics indicated no risk of mold growth – however because some of the metrics showed a potential for mold, additional analysis is recommended. Testing of the existing materials and specific data on proposed products should be used to refine this analysis and determine extent of mold growth risk.



    Written by Halla Hoffer, Associate, Architect I

    Overview of Architectural Styles in Oregon: 1840s to 1970s

    The City of Gresham applied for and was granted a CLG grant from the State Historic Preservation Office to increase community interest in historic preservation. The City felt that a presentation focused on architectural styles would be likely to generate some interest. They contacted PMA to find out if we would work within their budget and provide a powerpoint presentation geared towards citizens with no planning or architecture background, but also useful for City staff and historians. PMA was happy to be able to provide an overview of Oregon architecture styles from “settlement era” up until mid-1970s. The presentation highlighted the styles most likely to be seen in the Gresham area, especially residential and commercial uses. It was educational for our office to find those historic properties in Gresham and incorporate some of them into the presentation.

    Use, Type, Style
    It is difficult to understand style without an appreciation of the ways style can be overlaid on various types and uses of buildings. The USE of a building is its primary function. For instance, a church (use) might have a hall with steeple (types or forms) and be Neoclassical (style). The use or purpose of a building is strongly linked to its form, but even within a category of use such as residential, one might find various types such as “apartment block,” “bungalow,” or “four-square.” TYPE just means the basic form, so it is useful for historians to categorize these forms into expected sizes or arrangements of volumes. An apartment block is generally a simple rectangular building with several apartment units and a shared entry. A bungalow is simply a small house, one or 1.5 stories, horizontal in expression. Bungalows are often Craftsman in style, but a handful of other styles are sometimes used with a bungalow type. A four-square is a larger house, typically 2 or 2.5 stories, consisting of a somewhat square footprint with 4 rooms on each floor, and a broad front porch with columns or posts.

    The building’s STYLE is determined by the architectural and ornamental details and exterior features applied to the basic structure. Styles change with the times. In fashion and out of fashion, some endure longer. The timeline included is generally reflective of Oregon architectural fashions. However, style also can be affected by technology- for example, the development of steel frame buildings allowed for a new style to emerge: Modernism. Older bearing-wall masonry construction only allowed for small windows set between structural wall areas. A proliferation of new building types, such as the geodesic dome, occurred in the Modern era.

    We categorize buildings by type, use, and style when doing a survey of resources in a particular area. The data can be compared quickly and easily to data from other surveys, so we can see the patterns and history of development emerging in any particular area.

    Stylistic Timeline of Architectural Styles in Oregon
    From Vernacular Forms and Styles, to Renaissance Revivals, Northwest Regional Style and Post Modern, Oregon has a robust and diverse vocabulary of architecture. The stylistic timeline below is meant as a broad overview, highlighting key attributes per style listed, to help you identify your local and regional architectural resources.

    OR-Arch-Overview-Stylest-1
    OR-Arch-Overview-Stylest-2
    OR-Arch-Overview-Stylest-3
    OR-Arch-Overview-Stylest-4
    Written by Kristen Minor, Associate, Preservation Planner

    The Form and Function of Lighting Design

    When we experience an interior architectural space, lighting plays a large role in setting the mood and functionality of a space. No matter an existing, modern or historic building, light of a space is a critical aspect of great interior design. Lighting elements can be designed to enhance the space and architectural details, set the mood, and compliment furniture, color schemes, and art work. For spaces without an abundance of natural light, lighting design becomes even more critical design consideration. For a recent project, PMA designed lighting schemes for two historic four-story tall interior atriums.

    The existing atriums utilize natural light from skylights above; however the original design provided no artificial overhead lighting in the space. During the winter months or at dusk and night, the light quality of space relies on the little ambient light from the skylights or artificial light from the surrounding rooms and halls. The light during these times is inadequate for the necessary function of the space. PMA was tasked with providing a lighting solution that would sensitively address the historic nature of the atriums and provide adequate visibility in the space.
    pmapdx-lighting-design-004
    Defining the Project Challenges
    The concepts for our lighting schemes were based on the intended function of each identical space. The focus of the design and specified need of the client was to provide lighting for evening social gatherings, networking, and overall entertaining. Lighting needed to be adequate enough for speakers presenting to a crowd and for listeners to be able to read any related literature. Therefore, it was crucial to design lighting schemes that could provide ample lighting for evening events without compromising the historic integrity and ambiance of each space. To provide a solution for our clients’ challenge, we considered the following when approaching our design for the lighting schemes:

  • How to provide power to the source of lighting without compromising the historic elements.
  • Designing for large volumes of vertical space: hanging lighting within the atrium versus lighting from the top; how the light travels in the space, how it casts down shadows, the reflections off the floor and other surfaces.
  • One atrium exhibits permanent hanging sculptures and art; the lighting design required minimal approach to integrated and highlight the sculpture without distracting from it.
  • Designing for and highlighting the atriums’ architectural details, like the cornices, in addition how to hide or incorporating other non-historic architectural details like the structural support columns.
  • pmapdx-lighting-design-002
    Methodology for Design Solutions
    The prominent design goal was to increase overall light levels through a refined, modern scheme that would provide juxtaposition to the historic architectural elements and hanging sculpture. As in any historic project, it is important to avoid solutions that are faux historic, competing with, compromising, or confusing the original historic character. The few pragmatic design parameters defined by the client allowed for design freedom to provide several unique, distinct solutions. While creating our designs, PMA experimented with the type of fixtures (down lights, sconce, defused) and placement of these fixtures within the large volume of the atriums. PMA explored these options in a Revit model of the atrium spaces, which enabled evaluation of the design solutions through lifelike renderings that portrayed the quality and levels of light. Illuminance studies of lux levels provided a way to evaluate each design and provide refinement to meet necessary levels defined by the function of the space. Some lighting design options included:

  • Design lighting to highlight and contrast architectural features from surroundings, for example placing fixtures in the cove of architecture cornices located above openings within the atrium.
  • One atrium has a glass block floor element which could be illuminated from below to provide a dramatic light feature.
  • Accenting the verticality of the space with defused ribbon lighting set within the non-historic structural C-channels. This would transform these elements into elegant vertical lines leading the eye to the above skylights.
  • Pendant lights interspersed between sculptures would provide orbs of light to highlight elements of the sculpture. These fixtures would provide defused-light with optional downlights within the same fixture.
  • Suspended down lights at top of atrium with lights accenting sculptures from above and side.
  • Wall sconces to accents light and wash the atrium walls and columns; this would provide an overall glow to the space.
  • pmapdx-lighting-design-001
    pmapdx-lighting-design-003
    Scheme 1 unified serval lighting design ideas to provide different light level options in the space. Wall sconce lights provide general illumination of the space. Large circular hanging fixtures consist of defused tube lights and large circular defused downlights. Each group of fixture types can be controlled independently and dimmed to provide the ambience desired.

    Scheme 2 specifically works with the sculptures in the second atrium space. Vertical ribbon lights provide ambience illuminance of the space while concealing non-historic structural elements. Pendant lights hang interspersed within the sculptural elements. These have a defused light with an option for downlights. Each grouping of fixtures can be illuminated together or separately depending on the quality of light needed.

    Scheme 3 was chosen by the client and until announced must remain confidential. Stay tuned for the reveal.


    Written by Hali Knight.

    2016 Year in Review

    As we look back over the past year and reflect on our completed, on-going, and upcoming projects, we’d like to take the opportunity to say we have truly enjoyed collaborating and communicating with you!!
    pmapdx-2016-holiday

    2016 PROJECT HIGHLIGHTS
    PMA-2016-year-in-review
    From top, left to right: Studio Building Exterior + Window Assessment (Portland, OR); Joseph Vance Building Exterior Envelope Repair (Seattle, WA); PPS Grant High School Modernization (Portland, OR); SPS Magnolia School Renovation (Seattle, WA)

    PMA HAPPENINGS
    2015-2016-Halla-HWe are excited to announce: Halla Hoffer, Associate, successfully passed her ARE and is a licensed Architect in the state of Oregon.

    Halla is passionate about rehabilitating historic and existing architecture – integrating the latest energy technologies to maintain the structures inherent sustainability.

    PMAPDX-silver-to-goldWe are committed to the reuse and adaptability of existing resources, and in 2016 moved from Silver to Gold certification!

    State and Federal Historic Preservation Incentives Available in Oregon

    Historic Preservation Incentives at the State and Federal level are either tax incentives or grants. PMA keeps up to date regarding these programs as incentives are ever-changing and apt to suddenly sunset or be revised. Following is a brief explanation of incentives offered by state or federal government or private agencies as of 2016. PMA has worked with multiple owners and agencies across the Pacific Northwest to take advantage of state and federal tax incentive programs, and we can provide expert experience in the latest interpretations of work that meets the standards for these incentives. A few other redevelopment incentive programs are also mentioned below, if they have been successfully combined with historic preservation incentive programs in Oregon.
    1-oregon-state-capitol-building
    FEDERAL AND STATE OF OREGON TAX INCENTIVES

    Oregon Special Assessment

  • Properties contributing to a district or individually listed on the National Register and in need of some rehabilitation are eligible for the State of Oregon Special Assessment property tax incentive. Property taxes are “frozen” at the time of application and are held at that value for 10 years. During this time period owners may make significant investments in the property without an increase in assessed value. The earlier the investment is made and the larger the resulting increase in market value, the greater the benefit to the owner.
  • A Preservation Plan must be submitted, outlining the rehabilitation work proposed. Exterior work is prioritized, and the work must meet the Secretary of the Interior’s Standards for Rehabilitation. The total valuation of work must be at least 10% of the property’s Real market value and that amount must be spent in the first five years of the special assessment period.
  • A second term of 10 years is available, with some limitations on the types of preservation work that are eligible for the program. Eligible work includes energy conservation projects, ADA compliance, seismic improvements, or sustainability. The investment must meet or exceed 10% of the Real market value of the property at the time of application.
  • Non-contributing properties in need of rehabilitation could be eligible for the State of Oregon Special Assessment property tax incentive, if it is determined by the State Historic Preservation Office (SHPO) that the property is or would be eligible for listing on the National Register, and that the renovation would restore obscured or missing historic character.


  • Federal Historic Tax Credit Incentives (HTC)

  • Rehabilitation tax credits, in the amount of up to 20% of the amount spent on the project, are available to qualifying projects.
  • Property must be listed either individually or as a contributing property to a historic district listed in the National Register. Alternately, to qualify for up to 10% in tax credits, a non-designated building must have been constructed before 1936.
  • Property must be income-producing for at least 5 years after rehabilitation. Owner-occupied residential projects such as condominiums do not qualify, but apartments or mixed-use projects are eligible. The project must be substantial. The owner must spend more on rehabilitation expenditures than the “adjusted basis” value of the property. The Investment Tax Credit does not include the purchase price of the property.
  • Rehabilitation work must meet certain standards for preservation. These are the Secretary of the Interior’s Standards for Rehabilitation.
  • gus-solomon-interior-courtroom

    Federal Preservation Easement Tax Deduction
    A preservation easement is a legal agreement to protect a historic property from changes, including neglect. The property must be individually listed on the NRHP or a contributing structure within a National Register-listed historic district or local historic district. If a property owner makes a voluntary donation to a trust such as the Historic Preservation League of Oregon (HPLO) of all or a portion of a property, the donation can qualify as a charitable tax donation. Only some of the rights associated with the property are being donated, and the donation permanently limits uses or changes as specified. The owner of the historic property may still use the property, and must maintain it. The owner may sell the property, but the restrictions will remain with the property. The preservation easement may be structured to include only the exterior of a building, or may include air rights, interiors, grounds, or other features.

    OTHER INCENTIVES OR PROGRAMS

    Private and Public Grants
    Grants for historic preservation work vary widely as to eligibility rules, requirements, and amounts. While private-sector grant-making organizations are more apt to change grant programs or requirements year-to-year, they also are more likely to provide larger sums of money. Historic preservation grants are sometimes only available for preservation planning, survey, or designation work as opposed to “brick and mortar” projects.

    The State Historic Preservation Office (SHPO) administers Federal grants directly to local government entities through the Certified Local Government (CLG) program. The SHPO also administers State grants through the Oregon Heritage Grants, Oregon Museums Grants, Preserving Oregon Grants, Diamonds in the Rough Grants, and Oregon Historic Cemeteries Grants. These are all competitive and offer relatively modest amounts of funding.

    New Market Tax Credit
    In December 2015, Congress approved an extension of the New Market Tax Credit (NMTC) program through 2019. There is an immediate opportunity for investors, low-income communities, and businesses to use this successful program in order to revitalize economically distressed areas and create jobs. The State also runs the Oregon New Market Tax Credit program, which is modeled on the same requirements as the Federal program.

    The Blanchet House of Hospitality, a new (2012) building in a historic district in downtown Portland, used New Markets Tax Credits. NMTC and HTC have also been used together, such as in the Mercy Corps restoration/ expansion in the Skidmore Old Town historic district.
    The NMTC is not available for loans or investments in projects involving residential rental housing alone, but may be used for mixed-use and some other housing projects. Investments must be made to designated Community Development Entities (CDEs), which in turn provide investments in low-income communities. The investment is claimed over a 7-year credit allowance period.

    Low-Income Housing Tax Credits
    The federal government allots a certain amount per state per year to be awarded to developers willing to provide low income housing. Residential rental properties only may qualify for the Low-Income Housing Tax Credits (LIHTC) program. A certain percentage of the units must be restricted to occupants making 50% or less (or 60% or less) of local median income, and the affordability restrictions must be maintained for a minimum of 30 years. LIHTC has been successfully combined with HTC in downtown Portland projects such as the Admiral Apartments, the Martha Washington, and the Bronaugh Apartments.


    Written by Kristen Minor, Associate/Preservation Planner

    Local Historic Preservation Incentives Available in Portland, Oregon

    With a firm comprised of architects and planners, we understand and assist owners and developers navigate local historic preservation incentives made available by the City of Portland. The following is a comprehensive overview of incentives offered by the City, as of 2016, in the form of various use allowances, development rules “waivers,” and opportunities to transfer allowed but unused floor area to other property owners, creating an opportunity for a monetary benefit. We grouped the available historic preservation incentives available by the following: City of Portland Incentives, City of Portland/State of Oregon Building Code Allowances, and Portland Development Commission Programs.

    The City of Portland’s Central City 2035 Plan (as well as other related City code projects) are currently under review. The Proposed Draft was published in June 2016 and is being reviewed by many City and non-City agencies, bureaus, and organizations. Proposed changes directly affect portions of the Portland Zoning Code, but the existing Zoning Code will remain in effect until adoption of the final Central City 2035 Plan, probably in late 2018. Increased transfer options are the major change proposed.

    “Landmark” as defined by the City is a property individually listed on the National Register, or evaluated by the City of Portland as a local historic resource. Many incentives are also available to resources designated contributing to a National Register-listed Historic District or locally designated Conservation District.

    Marshall Wells Lofts building preservation plan.

    Marshall Wells Lofts building preservation plan.


    CITY OF PORTLAND INCENTIVES
    Additional density in Single-Dwelling zones. Landmarks in Single-Dwelling zones may be used as multi-dwelling structures, up to a maximum of one dwelling unit for each 1,000 square feet of site area. No additional off-street parking is required, but the existing number of off-street parking spaces must be retained. The landmark may be expanded and the new floor area used for additional dwelling units only if the expansion is approved through historic design review.

    Additional density in Multi-Dwelling zones. Landmarks and contributing structures in historic districts located in multi-dwelling zones may be used as multi-dwelling structures, with no maximum density. No additional off-street parking is required, but the existing number of off-street parking spaces must be retained. The building may be expanded and the new floor area used for additional dwelling units only if the expansion is approved through historic design review.

    Nonresidential uses in the RX zone. In the RX zone, except on certain sites which directly front on the Park Blocks, up to 100 percent of the floor area of a landmark or contributing structure may be approved for Retail Sales and Service, Office, Major Event Entertainment, or Manufacturing and Production uses through Historic Preservation Incentive Review.

    Nonresidential uses in the RH, R1 and R2 zones. In the RH, R1 and R2 zones, up to 100 percent of the floor area of a landmark or contributing structure may be approved for Retail Sales and Service, Office, or Manufacturing and Production uses as follows:

  • a. Review required. The nonresidential uses must be approved through Historic Preservation Incentive Review; and
  • b. Previous nonresidential use required. The last use in the structure must have been in a nonresidential use category and have been allowed when established; if part of the structure was in residential use, the proposal must include at least as many dwelling units as were part of the last allowed use or uses. If the last allowed use was residential only, the structure is not eligible for this incentive.

  • Daycare is an allowed use in all residential zones in historic landmark or contributing structures. In non-historic structures, daycare uses in residential zones other than RX require a conditional use review.

    Conditional uses in Residential, Commercial, and Employment zones. In these zones, applications for conditional uses at landmarks or contributing structures are processed through a Type II procedure, rather than the longer Type III procedure requiring a public hearing.

    Exemption from minimum density. Minimum housing density regulations do not apply in landmarks or contributing structures.

    Crane building historic consulting for storefront updates.

    Crane building historic consulting for storefront updates.


    Commercial allowances in Central City Industrial zones. National Register-listed properties or those contributing to a National Register-listed historic district have potential to include office and retail uses.

    Commercial allowances in employment and industrial zones. Office and retail uses are allowed in landmarks in areas where those uses are otherwise restricted.

    Increased maximum parking ratios in Central City. National Register-listed properties or those contributing to a National Register-listed historic district within the Central City Core parking area are allowed to increase parking ratios.

    Commercial allowances in Guild’s Lake Industrial Sanctuary District. Increases allowances for office and retail uses in landmarks in an area where non-industrial uses are otherwise restricted.

    The transfer of density and floor area ratio (FAR) from a landmark to another location is allowed in Multi-Dwelling, Commercial, and Employment zones. Historic properties with unused development “potential” therefore may find a market for the FAR.

    Proposed Development transfer opportunities (potentially adopted in 2018):
    Landmarks and contributing resources in historic districts will be able to transfer FAR City-wide, as long as the “sending” resource meets seismic reinforcement standards. Seismic work may be allowable in phases over a period of years. FAR to be transferred is not only the base amount unused by the existing historic structure, but also an additional 3:1.

    U.S. Custom House renovation and historic tax credits.

    U.S. Custom House renovation and historic tax credits.


    PORTLAND DEVELOPMENT COMMISSION PROGRAMS
    The Portland Development Commission (PDC) has operated several programs to benefit owners of existing buildings (not necessarily historic buildings). These programs have been suspended and will be replaced by the Prosperity Investment Program (PIP). Information about the PIP is not yet available, but the program may still provide benefits to owners, similar to the suspended Storefront Improvement Program.

    For further information on how PMA helps owners consider reuse options, navigate the regulations, and take advantage of available benefits – please visit our website to review our multidisciplinary projects and comprehensive architecture, building envelope science, and planning services.

    Written by Kristen Minor, Associate, Preservation Planner

    Back to School: A Historic Overview of Benson Polytechnic HS

    For a recent Portland Public School (PPS) project, PMA had the pleasure of creating a Historic Overview of Benson Polytechnic High School for a broader master planning project for the campus. The goal of the historic overview was to conduct an assessment of the school’s campus, highlight new building additions and alterations (changes overtime), and to identify and define historically significant spaces. As part of the historic overview, PMA reviewed historic drawings and photographs, PPS archival material(s) and coordinated discussions with school staff. Resources assessed included: Main Building (1916), North Shop Wing (1917), South Shop Wing (1918), Old Gym (1925), Auditorium (1930), Library Science Addition (1953), Aeronautics/Automotive Shop (1953), New Gym (1964), New Library Addition (1991), and KPBS (1992). Below is a snap-shot of our findings included in the Historic Overview of Benson Polytechnic High School.

    PPS-Benson-PMAPDX-library-historic

    photo courtesy of PPS archives.


    Background and History
    Benson Polytechnic High School was built in 1916 and designed by former architect and superintendent of school properties for Portland Public School, Floyd Archibald Naramore (i). Supported and funded by Simon Benson, a local lumber baron and philanthropist, the school was built to reflect modern educational ideals and the industrial arts. According to the 1915 school district board of directors meeting minutes, Simon Benson offered to donate $100,000 to the school district for “the purpose of building the first unit of a School of Trades, upon condition that the district contract to expend at least $100,000 during the year 1916, in the construction of a second unit to the school.” (ii) This donation was accepted by the school district, and in 1916 construction began.

    Historic Overview
    Overall, Benson Polytechnic High School has shown significant changes over time. These changes have occurred to the campus as it has grown from just the main building in 1916 to the existing 10-unit campus it is today, and to most of the school buildings.

    Originally, the site just consisted of the main, rectangular-shaped building to the west of campus. Designed with the intent to grow over time on a six-block parcel, this building and its campus did. By 1924, the site included the north shop wing with saw-tooth roof and foundry building to the northeast, the south shop wing with saw-tooth roof to the south, and the boiler building in between them all. The site was connected by a covered walkway that ran from the east façade of the main building, along the north and east façades of the boiler building to the north wing shop along its south façade and the south wing shop along its north elevation. At this time, the site also included a one-story portable building to the southeast of the main building.

    By 1950, the site had grown again. At this point, the site included the old gym to the south of the main building, the auditorium to the north of the main building, and ten new portable classrooms, including an aviation classroom and shop where it is currently located, war production training building where KPBS is currently located, and a music room where the new library addition is currently located. During this time, the site still included the covered walkway that connected the building and remained relatively open.
    PPS-Benson-PMAPDX-Auditorium
    Significant Changes
    Currently, with the addition of the aeronautics/automotive shop and library science addition in 1953, the new gym in 1964, the new library addition in 1991, and KPBS in 1992, the Benson Polytechnic High School site is significantly different from its early beginnings. With the addition of these later period buildings, the site has become denser with the main building connecting to 50% of the campus buildings. The covered walk way has since been demolished leaving most of the site circulation to the interior. However, much of the site still reflects the school’s period style and building methods along the site’s two primary thoroughfares, NE 12 Avenue and NE Irving Street. Like the site, many of the early constructed buildings have changed as well.

    Of the five buildings built before 1930, the north wing and south wing shops have endured the most significant alterations. These alterations include the removal of their saw-tooth roofs, the additions of centralized locker-lined corridors, the reconfiguration of room sizes, the infill of original openings, and the replacement of original wood windows. The north wing shop experienced most of these alterations in 1958 and the south wing shop experienced all of these alterations in 1960. The two-story unit in the north shop wing underwent significant changes in 1977. These changes include the reconfiguring of most rooms, and the addition of new exterior CMU stairs and primary entrance, the removal of original staircases, wood columns, and chimney. The foundry room was also altered in 1977, as its second-level balcony and spiral staircase were removed and enclosed.
    PPS-Benson-PMAPDX-Library
    Well Preserved Character Defining Features
    Overall, the character-defining features throughout each building are well preserved. This retention of several original interior spaces, features, and finishes contribute to Benson Polytechnic’s High School good historic integrity. As this school and campus continue to change, its significant structures and their character-defining features will add to the rich vitality of the school and contribute to the importance of the school as a community asset.

    PPS-Benson-PMAPDX-Site-Plan
    Sources
    (i) Entrix, “Oregon Historic Site Form: Benson High School,” Oregon Historic Sites Database, compiled 2009, http://heritagedata.prd.state.or.us/historic/index.cfm?do=v.dsp_siteSummary&resultDispl ay=50450.

    (ii) Meeting of the Board of Directors, School District No. 1, July 31, 1915.


    Written by Kate Kearney, Associate, in conjunction with PMA Planning staff.

    Means and Methods of Architectural Design

    On a recent trip to Italy, I couldn’t help but contemplate the progression of architecture styles across time and contemporary architecture’s divergence/evolution from past practice. Architecture, alongside art, has long reflected contemporary trends, culture, and politics. More than ever, contemporary architecture reflects our societies’ obsession with technology, efficiency, and value-engineering. As I stood within the walls of Carlos Scarpa’s Brion Cemetery, taking in the attention to detail and crafted experience of the space, I wondered if architecture would ever return to this level of craft, detail, and whimsy. It is hard to image Carlos Scarpa’s intricate and unique detail being created in the architectural world today. From my perception, the art of architecture on a mass scale is being transformed to a systems and science of architecture where unique, non-functioning, artful details are being abandoned as superfluous and cost prohibited.
    Means-Methods-Architectural-Design-001
    A Paradigm Shift
    Great works of historic architecture were conceived by pen and paper as artistic minds envisioned each space on iterative gestural pages; translated from enigmas to sketches to drawings to reality. Materials were crafted by hand and details seamlessly integrated within each trade’s identity. Today’s paradigm shift toward Building Information Modeling (BIM), factory production, and intelligent building systems have transformed the means and methods of the tradition discipline. Traditional detailing known by each trade has been lost to time as architects and builders move to new systems. The design process has continued to evolve and transitioned to computer based iterative processes. This creates a new dialog where the computer program itself has an influence over the design.

    Architectural contemporary styles are named for the processes in which they were designed, such as Diagramism, Revitism, Scriptism, and Subdivisionism. These processes include designing in CAD, BIM, and other 3D programs, which can predominantly drive the design style and form. Architects and designers need to be aware of how architectural design is affected by each program’s restrictions and work flow tendencies. There can be a detachment for the final goal of the built form as we go down the virtual rabbit hole. The benefit of 3D modeling is that it allows designers to more fully comprehend form and its intersection with the overall building systems. However, if the design process is pushed into modeling without a strong concept, the objective can be easily replaced with creating a well-organized and systematic Building Information Modeling, instead of holistic architectural design.
    Means-Methods-Architectural-Design-002
    Architectural Design and BIM
    BIM designs are based primarily of component systems that create efficient, intelligent, and informative models. Designers can easily draw schedules and quantities that greatly speed up processes, however in the design process, focusing on components can also create a disassociation from the whole building and design concept. The translation of an artistic gesture of a material or space can easily be lost in the clunky world of 3D representation and restrictions.

    I am certainly a proponent of BIM, but I am also an advocate of preserving the art and craft of architecture. BIM is a terrific for understanding buildings in their 3D form as a composition of components and systems. BIM’s intelligence allows for continued updating of schedules and quantities, allowing for time efficiency. However, these components are limited to the software’s modeling options and the designer’s skill at modeling. The virtual world is still not an accurate representation of all the properties of building materials or their structural capabilities. In other words, BIM cannot be a means from the start to the end. Our profession is obligated to continue to push for high design standards and syndicate and extrapolate. I continue to see architecture that either allows BIM to drive design or prioritizes efficiency and value-engineering over quality of design. As BIM evolves within architecture as a means to design, I hope it can assist designers in their creative process and challenge our profession’s boundaries.

    Written by Hali Knight, Architect I

    Sources
    Prospect Magazine
    Archdaily
    DI

    Post Modern Building Materials Part Two

    Post Modern Architecture: Documentation and Conservation
    At the DoCoMoMo US, Modern Matters, conference April 2013 in Sarasota, Florida, DoCoMoMo Oregon presented a debate on the merits of Michael Graves Portland Building and on the larger context of Post Modernism in general. A lively debate at the end of the presentation centered on the merits of DoCoMoMo incorporating Post Modern under the mission of the organization. In general, the support, or lack of support, for an expanded interpretation separated into two distinct viewpoints. The division represented the difference between individuals that look at Post Modernism as a historic event and individuals that still perceive Post Modernism as bad design even if executed within their own practice.
    pomo-part-two-document
    In a seemingly short period of time, a lot has transpired since 2013 regarding the conservation of Post Modernism. After a presentation on Post Modernism: Are You Prepared to Protect It during the Modern Heritage track at the October 2014 Association for Preservation Technology (APT) Conference in Quebec City, the APT Board unanimously supported the need to get ahead of the technical issues associated with preserving Post Modern architecture.

    And in December 2015, the Princeton School of Architecture, educational forum for Michael Graves, hosted the Postmodern Procedures Conference. Described in the conference outline, there was a “particular emphasis on methods of documentation and analysis, technical and narrative drawing” related to Postmodern. Post Modern works, buildings, sites, and neighborhoods, as well as art works, are recognized as important design styles deserving conservation and further understanding of construction techniques. And many iconic structures are being negatively modified (Richard Meier, Bronx Development Center, 1977) or lost entirely (James Wines, Sculpture in the Environment (SITE), Best Product Stores, circa 1976). <1>

    Post Modern design was broadly practiced in both the United States and internationally. Large and small firms were attracted to the stylistic incorporation of classical western design vocabulary in stark juxtaposition against the plain, unadorned, square box that many argued architecture had become. Post Modern architects, engineers, and material suppliers were pushing new materials and innovative construction technologies as a way to create Post Modern design elements. Continuous innovation in building skins reintroduced porcelain enamel panels, a product brought by Lustron to the building industry during the housing boom following World War II. New skins made from Glass Fibre Resin (GFR) capable of being molded in classical curves and ornamental shapes favored by Post Modern design were created. Innovations in brick technology including large scale brick panels made from a single wythe of masonry to panels whose outer face was only one half inch of masonry, or thin bricks. Improvements in resins created new wood or simulated wood products and adhesives for mounting faux finishes to structural systems. Perhaps one of the more ubiquitous new materials used in the creation of Post Modern architecture was the faux stucco product Dryvit, an Exterior Finish Insulation System (EIFS). Like porcelain enamel panels, EIFS was introduced as insulated wall assemblies as a means to improve energy performance during the world’s energy crisis of the 1970s.

    Outside of dramatic assembly failures, particularly within the EIFS industry, that provide insight into Post Modern material and assemblies, much technological information has been relegated to the historical archives. Many Post Modern buildings incorporate systems or components that are neither produced nor currently assembled in similar manners due to improvements in technology and building envelope science. Therefore, the process and method of building restoration, rehabilitation, and/or focused envelope repair could dramatically impact the exterior character of Post Modern structures.

    Focusing on one popular building skin material, Alucobond, much in use during the 1980s provides insight into the need for more research and deeper understanding of Post Modern assemblies and how to conserve and protect these systems.
    portland-building-materials-detail
    Origins & Development
    Alucobond falls into the category of aluminum composite panels (ACP) or sandwich panels. Alcan Composites & Alusuisse invented aluminum composites in 1964 and commercial production of Alucobond commenced in 1969, followed by Dibond in 1989.<2> ACPs are used in a variety of industries ranging from aerospace to construction. Perhaps the most well recognized structure using ACP is the Epcot Center’s Space Ship Earth built in 1982. However, it is the work of Richard Meier and I.M. Pei during the 1980s that brought Alucobond into the forefront as an architectural cladding material. Several different skin materials are available including aluminum, zinc, copper, titanium and stainless steel.

    Manufacturing
    The major aluminum raw ingredient, bauxite, is mined throughout the world with US sources coming from Georgia, Jamaica, and Haiti. Processing of the bauxite predominantly occurs near the ocean ports, like Corpus Christi, where the raw material is off loaded. Manufacturing starts from either solid blocks of aluminum made into coil sheets or directly from pre-manufactured coil sheets. Assembly occurs along a continuous operating line that bonds the weather (exterior) and interior faces to the core, cuts the panel to length, and produces special shapes as needed.

    Aluminum Composite Panels (ACP) are high-performance wall cladding products typically consisting of two sheets of nominal 0.020″ (0.50 mm) aluminum permanently bonded to an extruded thermoplastic core (polyethylene). Assemblies in the mid-1980s would often consist of curtain wall sub-components with sheets of aluminum on the exterior and insulation placed behind the aluminum sheets. (See fig)

    ACP can be roll formed to curve configurations for column covers, architectural bullnoses, radius-building corners and other applications requiring radius forming. This process can be accomplished with a “pyramid” roll forming machine, which consists of three motor-driven adjustable rollers. You can successfully roll form ACP using machines with minimum 2 1/2″ (64 mm) diameter rolls. The operator normally makes multiple passes of the panel through the rollers to gradually obtain the desired radius. <3>
    pomo-part-two-methods-install
    Use & Methods of Installation
    Post Modern assemblies generally assumed water would get behind the face aluminum panel and need a weep path to exit the system. Air gaps were incorporated to induce drying and allow for weeping via gravity. Wind loads were accommodated through additional brackets, or stiffeners, set behind the face panel and connected to sub-framing. Much of the technology was based on curtain wall knowledge.

    The panel systems could often be complex in the attachment to the structure, but the face panels were very similar to panels of today.

    Conservation
    Deterioration mechanism are generally associated with the system assembly and rarely are there failures in individual panels beyond cosmetic damages to the face aluminum including fading colors, scratches, and impact damages. More often incorrect fasteners were used that create galvanic reaction between the fastener and aluminum panel or inadequate fasteners were used to accommodate structural loads. The lack of design for thermal movement between panels, over the height and length of the panel façade, or along edge interfaces with sealants are also key areas of assembly failures.

    Fortunately manufactures of Alucobond, or other aluminum composite panels, are still manufacturing the panel and components making in-kind replacement a viable conservation option. Inadequate structural systems can be reinforced through disassembly of the ACP for access to the structural support. Laser scanning technology has greatly enhanced the accuracy of recording existing conditions and is critical in reproducing replacement panels. Although labor intensive, most of the systems were attached using stainless steel fasteners. Like modern curtain walls, sealant and gaskets will be removed during disassembly and require reinstallation.

    Repainting or repairing surface defects is feasible but the results generally do not achieve the same quality of finish as the factory applied coating process. And as with all repainting projects, surface preparation is critical to the long-term success of the project.

    Loss of original Post Modern aluminum composite panel systems can be reduced through an increasing interest and research into the original design intent and assembly techniques. ACP were incorporated into Post modern structures because of the simplicity to create the curved forms and for rapid pace of construction. The systems are an important part of understanding Post Modernism and worthy of Conservation.

    Marquette Plaza (historic photograph)

    Marquette Plaza (historic photograph)

    Written by Peter Meijer, AIA, NCARB, Principal

    Preservation and Ballparks: A Survival Guide for the
    American Ballpark

    Since the creation of the ballpark in 1862 and the much later inception of the National Preservation Act of 1966, preservation and ballparks have not necessarily been synonymous with each other, especially when referring to those used for Major League Baseball. To further the point, of the 109 stadiums, ballparks, or fields used by Major League Baseball since 1876, only 43 exist today, and of those 43, only 9 are 50 years of age or older. This does not mean, however, that only 9 Major League Baseball stadiums have ever reached or even surpassed 50 years of age; it just means that meeting one of the most fundamental benchmarks in preservation does not guarantee survival. For that matter, neither does being listed on the National Register of Historic Places. Although preservation is practiced and taught through the lens of the National Park Service’s preservation standards, there are multiple factors that contribute to the preservation of a historic resource. Like anything, there is rarely, if ever, a single answer to solving a complex issue. This leaves the question, if not the existing preservation framework, what factors do contribute to the preservation of historic resources, specifically historic major league ballparks?
    baseball-historic-stadiums-pmapdx
    Though an intriguing question, it will not be completely answered in this observational study, given the number of variables for each resource. However, by analyzing the 9 existing Major League Baseball stadiums that have survived to reach the age of 50, Fenway Park (1912), Wrigley Field (1914), Los Angeles Memorial Coliseum (1923), RFK Stadium (1961), Hiram Bithorn Stadium (1962), Dodgers Stadium (1964), The Astrodome (1944), Angel Stadium (1966), and the Oakland Coliseum (1966), this study begins to quantify what factors have contributed to their prolonged survival and identifies two common elements: function and adaptability. This study also provides information that can be useful in steering and focusing preservation efforts toward the successful preservation of baseball stadiums, ballparks, and fields. Nevertheless, it should also be understood that, though the findings of this study identify patters of preservation, these patterns should not be used to determine historic significance or integrity.

    Elements of Survival
    The first and most obvious element of survival for the 9 historic Major League Baseball stadiums is their function. No function, no purpose. Easily said and just as easily true. Of the 9 existing historic ballparks, 8 are currently being use by a Major League Baseball franchise or other sports program, as they were originally intended. The Astrodome is the only ballpark of the 9 that is currently vacant. With the exception of the Astrodome, which is pending rehabilitation, 8 out of 9 (88.9%) of all historic ballparks are functional. Whether through baseball, football, or soccer, keeping ballparks functional will not only contribute to their purpose for existence, but can keep them extant. In cases where Major League Baseball franchises or other sports programs build new stadiums, relocate, or disband, it is critical that the existing or remaining ballpark, stadium, or field finds a function, preferably one that utilizes its original design intent. Without it, its odds of demolition are significantly increased, regardless of its age, history, or cultural importance.

    Ballpark Styles
    Another common element of survival that these historic ballparks share is their ability to adapt to an evolving sport and culture through alterations. Though this use of alteration, in terms of renovation or rehabilitation, is a common standard within the National Park Service’s preservation rubric, ballparks are unlike other architectural forms because they are in a constant discourse with the sport of baseball, which has historically contributed to their continued evolution. Out of this relationship, four primary ballpark styles were created: The Pre-Classic (1871-1909), Classic (1909-1953), Modern (1953-1992), and Retro (1992–present). These styles, from the modest, wooden, Pre-Classic ballpark to the predominant, contemporary, Retro style ballpark, are equally representative of the sport and our society during their time of construction, thus contributing to their demolition when both evolved. Given this inherent fate, ballpark demolition is as common to the sport as superstition. So common, that an average of 16 ballparks have been demolished during each stylistic trend. However, those that have defied this characteristic have done so through their ability to mend both sport and cultural trend by adaptation.

    Ballpark Alterations
    After analyzing the histories of each of the 9 historic ballparks, 100% have undergone some form of alteration in pursuit of modernity. The most common alteration made was the addition or renovation of seating. The least common alterations made were the addition of kids’ play areas and the addition or renovation of dugouts. These statistics are expanded in the Historic Ballpark Alteration Chart. This chart shows past, undergoing, and projected alterations to each of the 9 historic ballparks observed in this study. Depending on age, these alterations, which include renovations and additions, may have been made to the same ballpark more than once.
    Historic-Ballpark-Alteration-Chart_PMAPDX
    Overall, these alterations have unquestionably contributed to the extended lifespan of each of these ballparks. This has allowed 5 of them to obtain historic status, either nationally or locally, one of which used Federal Historic Preservation Tax Credits. More importantly, they all have retained their function and purpose, while not all alterations made to these ballparks align with the National Park Service’s preservation standards.

    Titled “Preservation and Ballparks: A Survival Guide for the American Ballpark,” this study is meant to propel the discussion of the question: what factors contribute to the preservation of major league ballparks? Other factors that need further examination to truly understand the holistic approach to preserving ballparks are: 1) the financial impacts of preserving, redeveloping, or repurposing a ballpark; 2) the impact that a ballpark has on team success, franchise revenue, location and fan base; 3) and local preservation laws and ordinances for historic resources. Additionally, for further statistical analysis, this study would need a larger sample size, which includes historic minor league ballparks.

    Overall, this study reinforces some of the most important and fundamentally crucial elements in preservation: function and adaptability. Though the findings made in this study are not new to the preservation field, the perspective of what elements contribute to preservation of a single utilitarian form, such as the ballpark, is. More importantly, this study also reinforces the necessity for change and growth for all structures, even if falling outside of national preservation standards. This does not mean that with change comes demolition, but that change should be embraced, as it has been for these 9 major league ballparks.

    Written by Brandon J. Grilc, Preservation Specialist

    Bibliography
    Ballparks of Baseball. Dodgers Stadium. http://www.ballparksofbaseball.com/nl/DodgerStadium.htm.

    Ballparks of Baseball. RFK Stadium. http://www.ballparksofbaseball.com/past/RFKStadium.htm.

    Charleton, James H. Los Angeles Memorial Coliseum National Register of Historic Places Nomination Form. Washington D.C.: National Park Service, 1984.

    Chicago Cubs. History. http://chicago.cubs.mlb.com/chc/ballpark/information/index.jsp?content=history.

    Chicago Cubs. Construction Timeline. http://cubs.mlb.com/chc/restore-wrigley/updates/timeline/.

    Cook, Murray. “Murray Cook’s Field & Ballpark Blog,” Hiram Bithorn Stadium Upgrades for 2010 (blog), May 26, 2010. http://groundskeeper.mlblogs.com/?s=hiram+bithorn+stadium.

    Donovan, Leslie, Rachel Consolloy Nugent, Erika Tarlin, and Betsy Friedberg. Fenway Park National Register of Historic Places Nomination Form. Washington D.C.: National Park Service, 2012.

    Georgatos Dennis. “Renovations Reshaping Oakland Coliseum.” http://www.apnewsarchive.com/1996/Renovations-Reshaping-Oakland-Coliseum/id-d9a080536647dd0a356dcbd51efd4095.

    Grilc, Brandon J. “Stealing Home: How American Society Preserves Major League Baseball Stadiums, Ballparks, & Fields.” Thesis., University of Oregon, 2014.

    Los Angeles Angels of Anaheim. Angel Stadium History. http://losangeles.angels.mlb.com/ana/ballpark/information/index.jsp?content=history.

    Los Angeles Dodgers. Dodger Stadium History. http://losangeles.dodgers.mlb.com/la/ballpark/information/index.jsp?content=history.

    Los Angeles Dodgers. Dodger Stadium Upgrades. http://losangeles.dodgers.mlb.com/la/ballpark/stadium_upgrades/.

    Melendez, Sara T. Aponte. Hiram Bithorn Municipal Stadium National Register of Historic Places Nomination Form. Washington D.C.: National Park Service, 2013.

    Powell, Ted. The Astrodome National Register of Historic Places Nomination Form. Washington D.C.: National Park Service, 2013.

    Sillcox, Scott. Heritage Uniforms and Jerseys: A celebration of historic NFL, MLB, NHL, NCAA football and CFL uniforms and stadiums/ballparks/arenas. http://blog.heritagesportsart.com/

    University of Southern California. The Coliseum Renovation. http://coliseumrenovation.com/overview.