Evaluation of Two CEDAWeatherization PilotImplementations of anExterior Insulation and Over-Clad Retrofit Strategy forResidential Masonry Buildingsin ChicagoBuilding America Report - 1311August 2013Ken Neuhauser

Abstract:

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This project examines the implementation of an exterior insulation and over-clad strategy for brick masonry buildings in Chicago. The strategy was implemented at a free-standing two story two-family dwelling and a larger free-standing multifamily building. The test homes selected for this research represent predominant housing types for the Chicago area. High heating energy use typical in these buildings threaten housing affordability. Uninsulated mass masonry wall assemblies also have a strongly detrimental impact on comfort. Significant changes to the performance of masonry wall assemblies is generally beyond the reach of typical weatherization (Wx) program resources. The Community and Economic Development Association of Cook County, Inc. (CEDA) has secured a Sustainable Energy Resources for Consumers (SERC) innovation grant sponsored by the United States Department of Energy (DOE). This grant provides CEDA the opportunity to pursue a pilot implementation of innovative approaches to retrofit in masonry wall enclosures. The exterior insulation and over-clad strategy implemented through this project was designed to allow implementation by contractors active in CEDA weatherization programs and using materials and methods familiar to these contractors. The retrofit measures are evaluated in terms of feasibility, cost and performance. Through observations of the strategies implemented, the research described in this report identifies measures critical to performance as well as conditions for wider adoption. The research also identifies common factors that must be consid-ered in determining whether the exterior insulation and over-clad strategy is appropriate for the building.

Evaluation of Two CEDA Weatherization Pilot Implementations of an Exterior Insulation and Over-Clad Retrofit Strategy for Residential Masonry Buildings in Chicago Ken Neuhauser Building Science Corporation

August 2013

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Evaluation of Two CEDA Weatherization Pilot Implementations of an Exterior Insulation and Over-Clad Retrofit Strategy for

Residential Masonry Buildings in Chicago

Prepared for:

The National Renewable Energy Laboratory

On behalf of the U.S. Department of Energys Building America Program

Office of Energy Efficiency and Renewable Energy

15013 Denver West Parkway

Golden, CO 80401

NREL Contract No. DE-AC36-08GO28308

Prepared by:

Ken Neuhauser

Building Science Corporation

30 Forest Street

Somerville, MA 02143

NREL Technical Monitor: Cheryn Metzger

Prepared under Subcontract No. KNDJ-0-40337-02

2013

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Contents List of Figures ........................................................................................................................................... vii List of Tables .............................................................................................................................................. ix Definitions.................................................................................................................................................... x Executive Summary................................................................................................................................... xi 1 Problem Statement............................................................................................................................... 1 2 Project Context ..................................................................................................................................... 3

2.1 Chicago Masonry Buildings ................................................................................................3 2.2 CEDA Weatherization .........................................................................................................3 2.3 BSC-CEDA Research Collaboration ...................................................................................5

3 Relevance to Building Americas Goals............................................................................................. 6 4 Cost Effectiveness ............................................................................................................................... 7

4.1 Factors Affecting Cost Effectiveness...................................................................................7 4.2 Tradeoffs and Other Benefits...............................................................................................8 4.3 Contrast to Interior Insulation Strategies .............................................................................9

5 Research Project Description ........................................................................................................... 10 5.1 Research Questions............................................................................................................10 5.2 Technical Approach ...........................................................................................................10 5.3 Subject Buildings ...............................................................................................................11

5.3.1 Two-Family Building.............................................................................................11 5.3.2 Larger Multifamily Building..................................................................................12

5.4 Data Sources ......................................................................................................................14 5.4.1 Field Observation...................................................................................................14 5.4.2 Interviews with Contractors...................................................................................14 5.4.3 Bids and Other Project Documents........................................................................14 5.4.4 Performances Measurement...................................................................................14 5.4.5 Simulation Analysis ...............................................................................................15

6 Over-Clad Retrofit Assembly............................................................................................................. 16 7 Assessment......................................................................................................................................... 25

7.1 Implementation Observations ............................................................................................25 7.1.1 Painted on Air/Water Control ................................................................................25 7.1.2 Framing ..................................................................................................................28 7.1.3 Insulating Sheathing...............................................................................................30 7.1.4 Strapping................................................................................................................31 7.1.5 Parapet....................................................................................................................33 7.1.6 Base of Wall...........................................................................................................37 7.1.7 Window Surround..................................................................................................40 7.1.8 Cladding and Finish ...............................................................................................49

7.2 Cost Analysis ........................