How Old Red Brick can be the New Green by Beth Lavelle

How Old

Red Brick can be the New Green

A study of building enclosure upgrades for historic brick buildings.

Beth Lavelle | University of Oregon School of Architecture and Allied Arts Sean Scott, Advisor. Ankrom Moisan Architects.

Acknowledgements This project would not have been possible without the feedback, guidance, and support of multiple building professionals. Thank you. Project Advisor: Sean Scott, Ankrom Moisan Architects Energy Modeling: Jeff Olden, GLUMAC Building Enclosure Design and Detailing: Mark Perepelitza, SERA Architects John Duncan, Morrison Hershfield Construction Cost Estimating: Mike Valencic, CGMAX Greg Warner, HGC Construction

Contents Introduction:

Location of Study Current Conditions of Building Stock Proposed Upgrades Metrics

Methods:

Existing Conditions Design of Proposed Upgrades Weighted R-Value (UA Calculations) Energy Modeling Cost Estimating

Results and Analysis:

Weighted R-Value (UA Calculations) Energy Modeling Cost and Payback Estimating

Conclusion Sources

Typical vacant buildings in Over-the-Rhine.

Typical occupied buildings in Over-the-Rhine.

Introduction This study began with an interest in the renovation of historic buildings and a desire to explore the most appropriate ways to upgrade them without degrading the fabric of irreplaceable building stock. Location of Study: The sample building for this study is located in Cincinnati, Ohio in a historic neighborhood called Over-the-Rhine. This neighborhood features the most intact collection of late 1800’s Italianate architecture in the country and is listed on the National Historic Register. Over-the-Rhine is in the midst of major investment and redevelopment, which provides the perfect opportunity to upgrade the historic buildings to current standards. The sample building was chosen to represent the typical condition in the neighborhood: small, multi-story residential buildings filling narrow lots with party walls on 2 sides. Current Conditions of Building Stock: Many buildings in Over-the-Rhine were built in the late 1800’s, and a significant portion of the original historic character remains intact. Buildings generally consist of an exterior shell of multi-wythe brick masonry walls, wood framed floors and roof, single-pane wood windows, and a low-slope roof. Following decades of neglect and decline, the buildings range in condition from needing minor repairs to uninhabitable with major structural damage. A study in 2002 found that more than 500 buildings in the neighborhood were vacant, and over 5,000 residential units were unoccupied. Of these vacant buildings and units, the ones that can be salvaged present a major opportunity to upgrade them to meet today’s standards. Due to the neighborhood’s placement on the National Historic Register, alterations to the exteriors of buildings are highly regulated and strongly discouraged if avoidable. For this reason, the proposed upgrades in this study are focused on what can be done to the interior to improve the building envelope. Each building must be evaluated on a case-by-case basis, and the proposed upgrades may not be appropriate based on the condition of the building and the amount of remaining historic character. Metrics: The sample building and proposed upgrades were studied and analyzed for the following metrics: weighted R-value (UA calculation), energy performance, cost of construction, and payback period. Additional qualitative metrics include occupant comfort and impact to historic character. 7

Option 1: “Good”

Option 2: “Better”

Option 3: “Best”

Opaque Wall

Load-bearing Brick Masonry (High water storage capacity)

Repoint brick and replace damaged bricks as needed (Improve Water Resistance)

Registered Historic District = Exterior Alterations Restricted

Seal wall for air infiltration as needed. (Improve Air Infiltration with minimal interior alterations)

Fur wall on interior and add 2” close-cell spray foam (Improve Air Infiltration, Thermal Resistance, and Vapor Drive into masonry wall)

Fur wall on interior and add 3” close-cell spray foam (Improve Air Infiltration, Thermal Resistance, and Vapor Drive into masonry wall)

Low-slope roof membrane on wood sheathing and wood rafters (Very Low Thermal Resistance)

Seal roof or replace membrane and sheathing as needed (Improve Water Resistance and Air Infiltration)

Replace membrane and sheathing (Improve Water Resistance and Air Infiltration)

Add 10” fiberglass batt insulation between roof rafters (Improve Thermal Resistance)

Add 6” mineral wool between roof membrane and sheathing (Improve Thermal Resistance)

Seal window frames as needed

Replace entire wood window and frame with new fiberglass window (Improve Air Infiltration and Durability)

Window

Existing Condition

Roof

Summary of Upgrade Options

Plaster and Lath Interior Finish

Wood frames (Significant Air Infiltration) Double-hung (Operability is important on hot summer days) Single-pane (Low Thermal Resistance) Registered Historic District = Exterior Alterations Restricted

Seal window frames and sashes as needed (Improve Air Infiltration with minimal alterations)

Replace existing sashes with new metal-clad wood sashes (Improve Air Infiltration with better seals) Double-pane Insulated Glass Unit (IGU) in new sashes (Improve Thermal Resistance) Add spray foam to existing window weight pocket

Double-pane Insulated Glass Unit (IGU) (Improve Thermal Resistance) Add liquid-applied membrane to rough opening and metal flashing to sill (Improve Water Drainage)

Methods Summary The first step in this project was understanding the existing conditions of the sample building and identifying the upgrades that would provide the most benefit for hygrothermal and energy performance as well as occupant comfort. The existing conditions provide good water storage within the wall, which manages moisture quite well if the brick is properly maintained. The weakest point of the existing assembly is the single-pane wood windows, which allow for a significant amount of air leakage and thermal transfer. This study proposes â&#x20AC;&#x153;Good, Better, and Bestâ&#x20AC;? upgrade options for the existing historic envelop. Option 1 focuses simply on reducing air leakage with sealant. This will not only have a dramatic affect on improving occupant comfort, but it can be hypothesized that it will also improve the energy performance significantly. Option 2 focuses on improving the air leakage, thermal performance, and vapor drive across the enclosure. Option 3 also accomplishes these tasks, but improves the thermal performance even more and improves the water shedding function of the enclosure at the window sills (a vulnerable point for water intrusion). Detailed drawings of the existing condition and upgrade options follow this summary. After designing and detailing, the upgrade options were tested for their weighted R-value (UA calculations), energy performance, construction cost and payback period. Each option was then compared against the existing conditions and the other options. The results and analysis are included in following sections. The following drawings and information are diagrammatic and for information only. They are not for construction.

MULTI-WYTHE BRICK EXTERIOR WALLS. EXPOSED BRICK ON EXTERIOR FACE, FINISH PLASTER AND LATH ON INTERIOR FACE. WOOD JOIST FLOOR STRUCTURE WITH WOOD PLANK FINISH. SINGLE-PANE WOOD DOUBLE-HUNG WINDOWS. WINDOW HEAD DETAIL

WINDOW ELEVATION

TYPICAL RESIDENTIAL UNIT

WINDOW SILL DETAIL

EXISTING WALL SECTION SCALE: 1/2” = 1’

Existing Conditions The existing enclosure of the sample building manages water quite well, but air leakage and thermal transfer are major opportunities for improvement. Window head, jamb, and sill detail drawigns follow, as well as an elevation which will be used to compare the upgrade options to the historic window profiles.

STONE LINTEL PLASTER AND LATH WOOD WINDOW FRAME AND TRIM SINGLE-PANE WOOD WINDOW SASH EXTERIOR BRICK FACE

EXISTING WINDOW HEAD SCALE: 3” = 1’

EXTERIOR BRICK FACE SINGLE-PANE WOOD WINDOW SASH WOOD WINDOW FRAME AND TRIM PLASTER AND LATH STONE SILL

EXISTING WINDOW SILL SCALE: 3” = 1’

MULTI-WYTHE BRICK EXTERIOR WALL WINDOW SASH WEIGHTS AND CAVITY SINGLE-PANE WOOD WINDOW SASH WOOD WINDOW FRAME AND TRIM PLASTER AND LATH

EXISTING WINDOW JAMB SCALE: 3” = 1’

EXISTING WINDOW EXTERIOR ELEVATION SCALE: 1/4” = 1’

Upgrade Option 1 This option involves very minimal alterations to the existing historic character of the enclosure. The focus of this option is to reduce air leakage across the enclosure to improve occupant comfort and increase energy performance for very little cost and impact to the building.

STONE LINTEL PLASTER AND LATH WOOD WINDOW FRAME AND TRIM NEW SEALANT BETWEEN FRAME AND ROUGH OPENING (AIR BARRIER COMPONENT) NEW COMPRESSION GASKETS (AIR BARRIER COMPONENT) SINGLE-PANE WOOD WINDOW SASH EXTERIOR BRICK FACE

OPTION 1 WINDOW HEAD SCALE: 3” = 1’

EXTERIOR BRICK FACE SINGLE-PANE WOOD WINDOW SASH NEW COMPRESSION GASKETS (AIR BARRIER COMPONENT) WOOD WINDOW FRAME AND TRIM NEW SEALANT BETWEEN FRAME AND ROUGH OPENING (AIR BARRIER COMPONENT) PLASTER AND LATH STONE SILL

OPTION 1 WINDOW SILL SCALE: 3” = 1’

MULTI-WYTHE BRICK EXTERIOR WALL NEW SEALANT BETWEEN FRAME AND ROUGH OPENING (AIR BARRIER COMPONENT) WINDOW SASH WEIGHTS AND CAVITY SINGLE-PANE WOOD WINDOW SASH NEW COMPRESSION GASKETS (AIR BARRIER COMPONENT) WOOD WINDOW FRAME AND TRIM PLASTER AND LATH

OPTION 1 WINDOW JAMB SCALE: 3” = 1’

NO CHANGE TO EXTERIOR

OPTION 1 WINDOW EXTERIOR ELEVATION SCALE: 1/4” = 1’

REPAIR ROOF MEMBRANE AS NEEDED (AIR BARRIER AND WATER SHEDDING COMPONENT) EXISTING PLYWOOD SHEATHING EXISTING WOOD ROOF RAFTERS EXISTING PLASTER AND LATH

EXISTING/ OPTION 1 ROOF DETAIL SCALE: 1 1/2” = 1’

Upgrade Option 2 This option builds upon the goals of Option 1, but also improves the R-value and vapor drive across the enclosure. Spray foam insulation added to the inside of the wall is the best way to achieve this: because spray foam can fill every small gap across the wall’s surface, it creates an airtight thermal layer that prevents convection currents from forming (which could cause condensation within the wall assembly and degrade the entire enclosure). Insulation is also added to the roof cavity for improved thermal performance. STONE LINTEL PLASTER AND LATH NEW CLOSED-CELL SPRAY FOAM INSULATION (AIR AND VAPOR BARRIERS AND THERMAL COMPONENT) NEW 1” X 2”WOOD FURRING STRIPS. SEE JAMB DETAIL ON A2.2. NEW GYPSUM BOARD EXISTING WOOD WINDOW FRAME TO REMAIN NEW SEALANT BETWEEN FRAME AND ROUGH OPENING (AIR BARRIER COMPONENT) NEW WOOD WINDOW CASING AND SALVAGED HISTORIC TRIM NEW DOUBLE-PANE METAL-CLAD WOOD WINDOW SASH INSTALLED IN EXISTING FRAME WITH NEW JAMB TRACK. SEE JAMB DETAIL ON A2.2. (AIR BARRIER, WATER RESISTIVE, AND THERMAL COMPONENT) EXTERIOR BRICK FACE

OPTION 2 WINDOW HEAD SCALE: 3” = 1’

EXTERIOR BRICK FACE NEW DOUBLE-PANE METAL CLAD WOOD WINDOW SASH INSTALLED IN EXISTING FRAME WITH NEW JAMB TRACK. SEE JAMB DETAIL ON A2.2. (AIR BARRIER, WATER RESISTIVE, AND THERMAL COMPONENT) NEW WOOD SILL AND STOOL NEW SEALANT BETWEEN FRAME AND ROUGH OPENING (AIR BARRIER COMPONENT) EXISTING WOOD WINDOW FRAME TO REMAIN NEW GYPSUM BOARD NEW CLOSED-CELL SPRAY FOAM INSULATION (AIR AND VAPOR BARRIERS AND THERMAL COMPONENT) NEW 1” X 2” WOOD FURRING STRIPS. SEE JAMB DETAIL ON A2.2. PLASTER AND LATH STONE SILL OPTION 2 WINDOW SILL SCALE: 3” = 1’

MULTI-WYTHE BRICK EXTERIOR WALL NEW SEALANT BETWEEN FRAME AND ROUGH OPENING NEW LIQUID-APPLIED MEMBRANE BETWEEN EXISTING FRAME AND NEW JAMB TRACK, WRAP INTO ROUGH OPENING (AIR BARRIER AND WATER RESISTIVE COMPONENT) NEW DOUBLE-PANE METAL CLAD WOOD WINDOW SASH INSTALLED IN EXISTING FRAME WITH NEW JAMB TRACK. SEAL TRACK ON INTERIOR AND EXTERIOR WITH BACKER ROD AND SEALANT (AIR BARRIER, WATER RESISTIVE, AND THERMAL COMPONENT) NEW CLOSED-CELL SPRAY FOAM INSULATION IN SASH WEIGHT CAVITY. INSTALL THROUGH PULLEY OPENING IN EXISTING JAMB AND COVER WITH WOOD PLUG (AIR BARRIER COMPONENT) EXISTING WOOD WINDOW FRAME TO REMAIN NEW WOOD CASING AND SALVAGED HISTORIC TRIM PLASTER AND LATH NEW CLOSED-CELL SPRAY FOAM INSULATION (AIR AND VAPOR BARRIERS AND THERMAL COMPONENT) OPTION 2 WINDOW JAMB SCALE: 3” = 1’

NEW 1”” X 2” WOOD FURRING STRIPS, 16” O.C. NEW GYPSUM BOARD

BOUNDARY OF EXISTING WINDOW

OPTION 2 WINDOW EXTERIOR ELEVATION SCALE: 1/4” = 1’

NEW ROOF MEMBRANE (AIR BARRIER AND WATER RESISTIVE COMPONENT) NEW PLYWOOD SHEATHING EXISTING WOOD ROOF RAFTERS NEW FIBERGLASS BATT INSULATION (THERMAL COMPONENT) EXISTING PLASTER AND LATH WITH VAPOR-RETARDER PAINT OPTION 2 ROOF DETAIL SCALE: 1 1/2” = 1’

Upgrade Option 3 This option builds upon the goals of Option 2, but improves the thermal performance of the enclosure even more. The spray foam insulation is thickened, and the roof insulation is move to the outside of the structure, reducing thermal bridging across the roof assembly. Flashing and a liquid-applied membrane is added to improve the moisture resistance of the window opening.

STONE LINTEL PLASTER AND LATH NEW CLOSED-CELL SPRAY FOAM INSULATION (AIR AND VAPOR BARRIERS AND THERMAL COMPONENT) NEW 1” X 2” WOOD FURRING STRIPS, INSTALLED 1” FROM WALL FACE. SEE JAMB DETAIL ON A3.2. NEW GYPSUM BOARD NEW WOOD WINDOW CASING AND SALVAGED HISTORIC TRIM NEW LIQUID-APPLIED MEMBRANE, WRAP BACK ANGLE (AIR BARRIER AND WATER RESISTIVE COMPONENT) NEW SEALANT BETWEEN FRAME AND ROUGH OPENING NEW DOUBLE-PANE FIBERGLASS WINDOW, SEALED TO NEW MEMBRANE AND WOOD CASING WITH BACKER ROD AND SEALANT (AIR BARRIER, WATER RESISTIVE, AND THERMAL COMPONENT) OPTION 3 WINDOW HEAD SCALE: 3” = 1’

EXTERIOR BRICK FACE

EXTERIOR BRICK FACE NEW DOUBLE-PANE FIBERGLASS WINDOW, SEALED TO NEW MEMBRANE WITH BACKER ROD AND SEALANT (AIR BARRIER, WATER RESISTIVE, AND THERMAL COMPONENT) NEW METAL FLASHING (WATER SHEDDING COMPONENT) NEW LIQUID-APPLIED MEMBRANE, WRAP BACK ANGLE (AIR BARRIER AND WATER RESISTIVE COMPONENT) LIGHT GAUGE BACK ANGLE NEW WOOD STOOL AND SALVAGED HISTORIC TRIM NEW GYPSUM BOARD NEW CLOSED-CELL SPRAY FOAM INSULATION (AIR AND VAPOR BARRIERS AND THERMAL COMPONENT) NEW 1”X 2” WOOD FURRING STRIPS, INSTALLED 1” FROM WALL FACE. SEE JAMB DETAIL ON A3.2 OPTION 3 WINDOW SILL SCALE: 3” = 1’

PLASTER AND LATH STONE SILL

MULTI-WYTHE BRICK EXTERIOR WALL NEW LIQUID-APPLIED MEMBRANE, WRAP BACK ANGLE (AIR BARRIER AND WATER RESISTIVE COMPONENT) NEW DOUBLE-PANE FIBERGLASS WINDOW, SEALED TO NEW WOOD CASING WITH BACKER ROD AND SEALANT (AIR BARRIER, WATER RESISTIVE, AND THERMAL COMPONENT) NEW WOOD FRAMING IN EXISTING SASH WEIGHT CAVITY NEW LIGHT GAUGE BACK ANGLE NEW WOOD CASING AND SALVAGED HISTORIC TRIM PLASTER AND LATH NEW CLOSED-CELL SPRAY FOAM INSULATION (AIR AND VAPOR BARRIERS AND THERMAL COMPONENT) NEW 1” X 2” WOOD FURRING STRIPS, INSTALLED 1” FROM WALL FACE. 16” O.C. NEW GYPSUM BOARD

OPTION 3 WINDOW JAMB SCALE: 3” = 1’

BOUNDARY OF EXISTING WINDOW

OPTION 3 WINDOW EXTERIOR ELEVATION SCALE: 1/4” = 1’

NEW ROOF MEMBRANE (AIR BARRIER AND WATER SHEDDING COMPONENT) NEW 6” POLYISOCYANURATE INSULATION (THERMAL COMPONENT) VAPOR BARRIER NEW PLYWOOD SHEATHING EXISTING WOOD ROOF RAFTERS EXISTING PLASTER AND LATH OPTION 3 ROOF DETAIL SCALE: 1 1/2” = 1’

Weighted R-Value (UA Calculations) In order to generate an overall picture of the performance of each option, the weighted R-value was compared to the existing conditions using simple UA calculations. These calculations use the R-value for each assembly (opaque wall, window, and roof) and the percentage of area for each assembly to generate a weighted value for the entire enclosure. R-values were calculated manually by adding the value for each material in the assembly, and were confirmed with COMFEN where possible. R-values are converted to U-values for accuracy and consistency. Step 1: Determine R-values for each assembly, for each option. Existing Conditions Option 1* Option 2 Option 3

Opaque Wall U 0.337 No Change U 0.118 U 0.074 (R 2.96) (R 8.46) (R 13.46) Roof U 0.483 U 0.038 U 0.031 (R 2.07) (R 26.43) (R 32.07) Window U 0.8948 U 0.2772 U 0.2081 (R 1.117) (R 3.6) (R 4.8) Step 2: Determine Area for each assembly (same for each option). Opaque Wall

5,382 square feet

77.3%

Roof 1,200 square feet 17.2% Window** 378 square feet 5.5% * Upgrades in Option 1 only affect amount of air infiltration, which is not represented in UA calculations. ** Due to the building configuration, windows only occur on the narrow front and back facades. The long side facades are party walls and do not have windows.

Step 3: Perform UA calculation. Existing Conditions Option 1* Option 2 Option 3 Opaque Wall x

0.337 U Value No Change 77.3% Area x 0.2605 UA

0.118 U Value 77.3% Area x 0.0912 UA

0.074 U Value 77.3% Area 0.0572 UA

Roof x

0.483 U Value 17.2% Area x 0.0831 UA

0.038 U Value 17.2% Area x 0.0065 UA

0.031 U Value 17.2% Area 0.0053 UA

0.895 U Value 5.5% Area x 0.0492 UA

0.277 U Value 5.5% Area x 0.0152 UA

0.208 U Value 5.5% Area 0.0114 UA

Window x Total UA Value

0.3928 U Value (2.546 R Value)

0.1129 U Value (8.857 R Value)

* Upgrades in Option 1 only affect amount of air infiltration, which is not represented in UA calculations.

0.0739 U Value (13.532 R Value)

Energy Modeling While the UA calculations are helpful to get an overview of performance, much of the design of the upgrade options focused on reducing air infiltration. The impacts of reduced air infiltration cannot be measured with simple UA calculations. Energy modeling was simulated for the sample building by Jeff Olden, an Energy Analyst for GLUMAC, Portland. The sample building was modeled in eQuest and included the following assumptions for each option. Energy Model Assumptions: Building Size: 3,600 square feet (20’W x 60’L x 36’H) 3 Stories above grade 3 residential units Systems: 80% Efficiency Gas Furnace Heating No Air Conditioning Domestic Hot Water, Lighting, and Plug Loads are typical and constant for this study. Baseline Energy*: 1950 KWH 1395 Therm Existing Conditions Option 1 Option 2 Option 3 UA Value 0.3928 0.3928 0.1129 0.0739 Infiltration Rate** cfm/minute

0.6

0.4

0.15

* Baseline Energy use is for whole building for an entire year. Based on energy bills for the sample building for January 2014. ** Infiltration rate is estimated and is not based on actual testing of the sample building. Estimates are based on professional knowledge and previous projects.

Cost Estimating and Payback Period In order to get accurate local cost information for this study, Cincinnati contractors Mike Valencic, CGMAX; and Greg Warner, HGC Construction provided square-foot cost information for each upgrade option. The cost information presented in this study is for estimating purposes only, and can vary dramatically with each projectâ&#x20AC;&#x2122;s specific challenges. Actual cost will vary from the information in this study; it is for comparison only. The cost information includes the following assumptions: Cost includes labor and materials for both demolition and construction. Additional project-specific costs are not included in these estimates, such as scaffolding, over-head utility shut-off, protection of other areas of the building, contingencies, etc. Once the overall cost was identified, a simple payback calculation was performed. This calculation used the energy cost savings (in following section) and assumed an energy inflation rate of 7% annually.

Weighted R Value Results (UA Calculation)

Results: Weighted R-Value (0.0739 U Value)

Weighted R Value

9 (0.1129 U Value)

(0.3928 U Value)

Existing Condition

Option 1

Option 2

Option 3

Results and Analysis Weighted R Value (UA Calculation) The weighted UA calculations revealed expected results for thermal performance. The existing conditions have a very low R value, while Options 2 and 3 show dramatic improvement with the addition of insulation in the walls and roof. This information was used to generate the energy model and the improved performance of Options 2 and 3 is reflected in the energy model results. While improved thermal performance is important and significant, the UA calculations cannot measure a reduction in air leakage. This calculation is over-simplified for accurate results for this study, but it is helpful in getting an overview of performance.

Summary of Options: Option 1: Seal for Air Infiltration Option 2: New Window Sashes, Insulation Option 3: New Windows, Insulation

Energy Modeling Results:Performance Energy Use Intensity Results: Energy 120

22%

kbtu/sf/year

Energy Use Intensity (EUI)

100

54%

55%

Average EUI*

Heating and Fans

Plug Loads Lighting

Existing Condition

Option 1

*Regional Average Site EUI for multi-family buildings 2-4 units. Data Source: U.S. Energy Information Administration. Jeff Olden, GLUMAC.

Option 2

Option 3

Hot Water

Energy Modeling Energy modeling by Jeff Olden accounts for both improved thermal performance and air leakage across the enclosure. These results show that there is a significant reduction in energy use from Option 1, which simply involves reducing air leakage with affordable sealant and roof repairs. As expected, greater energy savings result from higher levels of insulation, but the difference between Options 2 and 3 is minimal. This summary of the energy model also shows that upgrades to the enclosure can be very beneficial to reducing the heating load of the building, which is the majority of the energy use in this building type in this location. Enclosure upgrades are an affective way to reduce the energy use in historic brick buildings, and are a big step towards making Over-the-Rhine a more sustainable neighborhood. Using the energy consumption information for the sample building, the energy use savings can be translated into cost savings. The chart on the following page shows a dramatic reduction in the energy cost per square foot of building area, and is also presented as annual savings for the sample building. Cost savings will of course vary with each building, but this information can be used to estimate savings in other buildings to inform renovation projects.

Summary of Options: Option 1: Seal for Air Infiltration Option 2: New Window Sashes, Insulation Option 3: New Windows, Insulation

Results: Energy Savings

Energy Modeling Results: Savings

$1,113 $0.60

$0.50

$2,732

$2,782

Option 2

Option 3

$/sf/year**

Annual Energy Cost

$/whole building*

Annual Savings

$0.70

$0.40

$0.30

Existing Condition

Option 1

Data Source: Duke Energy. Jeff Olden, GLUMAC, Portland Oregon. * Annual Savings is an estimate based on usage for the study building: 3 stories, 3 units, 6960 square feet total. ** Annual energy costs are based on local electricity and gas prices for January 2014.

Summary of Options: Option 1: Seal for Air Infiltration Option 2: New Window Sashes, Insulation Option 3: New Windows, Insulation

Results: Upgrade Costs and Payback

Cost and Payback Estimating $10.00

years

Payback Period

$/sf

One-Time Upgrade Cost

$8.00

$6.00

25 $4.00

$2.00

Option 1

Option 2

Option 3

Data Source: Mike Valencic, CGMAX Cincinnati, Ohio. Greg Warner, HGC Constuction Cincinnati Ohio. Notes: 1. Upgrade costs are estimates. Costs do not include project-specific unknowns such as scaffolding and utility shut-off for exterior work. 2. Payback period assumes 7% annual inflation of energy prices.

Cost and Payback Estimating Construction cost information, provided by Mike Valencic and Greg Warner, shows how much each upgrade option will cost. Since this information will vary dramatically for each project, costs are shown per square foot of floor area and can be used to estimate future renovations. The payback period for each option is rather long, but if enclosure upgrades could be combined with other building upgrades to potentially reduce energy even further and decrease payback time. The payback period should also be considered against an expected improvement in occupant comfort and reduced tenant turnover.

Summary of Options: Option 1: Seal for Air Infiltration Option 2: New Window Sashes, Insulation Option 3: New Windows, Insulation

Overall Summary of Proposed Upgrade Summary Options Results: Overall

Impact to Historic Character

Occupant Comfort

Upgrade Cost

Energy Use

Hygrothermal Performance

Existing Condition

Option 1

Option 2

Option 3

Conclusion Summary of Options While weighted R value calculations, energy modeling, and cost estimating are important metrics to analyze enclosure upgrades, they must be balanced with other considerations such as occupant comfort and impact to historic character. Each project will have different constraints. A major factor affecting the reality of these upgrades in Overthe-Rhine is the impact to historic character. While some buildings have a significant amount of original character remaining (which would suggest that minimal interventions are the most appropriate), other buildings may have suffered significant decline and damage. Those buildings perhaps offer the most opportunity for more intense enclosure upgrades, and it is important to recognize and take advantage of these opportunities. Although this study does not provide a clear path that can be prescribed for all historic masonry buildings in Over-the-Rhine and elsewhere, it does provide a framework for measuring 3 upgrade options and a rough estimate on the results that can be expected after implementation. If these options are implemented, post-occupancy testing and monitoring could provide real data to further inform the best options for future interventions.

Summary of Options: Option 1: Seal for Air Infiltration Option 2: New Window Sashes, Insulation Option 3: New Windows, Insulation

Sources Baker, P. “Measure Guideline: Wood Window Repair, Rehabilitation, and Replacement.” Building Technologies Program. Building Science Corporation. U.S. Department of Energy. December 2012. Grondzik, Walter, et. al. Mechanical and Electrical Equipment for Buildings. 11th Edition. 2010 John Wiley and Sons. “Over-the-Rhine Green-Historic Study.” Over-the-Rhine Foundation. July 2009. Over-the-Rhine Comprehensive Plan. 2002. Straube, John and Chris Schumacher. Building Science Digests. “BSD-114: Interior Insulation Retrofits of LoadBearing Masonry Walls in Cold Climates.” March, 2007. http://www.buildingscience.com/documents/digests/bsd114-interior-insulation-retrofits-of-load-bearing-masonry-walls-in-cold-climates. Accessed January 8, 2014.