PEER – Prefabricated Exterior Energy Retrofit

Developing, testing and validating innovative prefabricated building envelope technologies for retrofitting existing Canadian homes from the exterior.

Opportunity

Canada’s 14.5 million dwellings account for more than one sixth of national energy use and close to 14 percent of Canada’s energy-related GHG emissions.^{Footnote 1} In retrofit programs to date, exterior wall insulation improvements were uncommon, even though walls often account for 25 to 35 percent of the heat loss of a typical existing home.^{Footnote 2} As Canadian jurisdictions introduce carbon pricing and policies targeting net-zero energy housing, significant levels of investment can be anticipated in housing energy retrofits in the coming years. This project seeks to develop technologies and processes for applying prefabricated components to retrofit existing homes and buildings from the exterior. This approach promises to dramatically improve energy efficiency and enhance aesthetics while reducing the cost and complexity of a conventional retrofit.

Research Methodology

Guided by an advisory committee to provide technical guidance and market intelligence, the project team will collaborate with industry partners to create technology specifications and build and test prototype prefabricated panels. The research will investigate and refine the workflow for converting 3D scans done on site into digital files for use by manufacturers to build custom panels for specific retrofit projects. Field tests of prototype prefabricated wall systems will be conducted to evaluate thermal and moisture performance as well as cost effectiveness. Finally, a technology development and deployment plan will be generated for commercialization of prefabricated wall systems for deep energy retrofits.

Vision, Goal and Objectives

The overarching vision of the PEER project is to enable the Canadian manufacturing and renovation industries to commercialize new prefabricated façade retrofit technology. The project goal therefore is to develop a process for conducting such retrofits and to prototype and test panelized retrofit kits. Project objectives include:

• Develop specifications and prototypes of prefabricated retrofit wall systems with a minimum RSI of 4.2 (R-24);
• Work with manufacturing partners to fabricate prototypes;
• Link with renovators/builders to install, test and measure thermal, air leakage and moisture performance of different types of retrofit wall assemblies for laboratory tests and field tests on various housing types;
• Develop a technology roadmap for commercialization and liaise with industry partners and renovators to establish dedicated service offerings for exterior deep energy retrofits. 

Tasks and Timeframes

High level project tasks and targeted completion dates are listed below.

Phase	Tasks	Targeted Completion
Collect data and establish consortium	Benchmark current retrofit best-practices to establish cost and performance targets Convene Advisory Committee Establish Consortium of Industry Partners and other stakeholders	Spring 2017
Analyze building stock, develop value proposition and business strategy	Analyze existing stock energy use, cost and GHGs by vintage and geography Review of international projects undertaking exterior home retrofits Develop innovation and business strategy	Summer 2017
Develop concept and evaluate	Develop digital workflow including building capture, Building Information Model (BIM), Computer Aided Manufacturing (CAM)	Fall 2017
	Develop panel concepts and designs Conduct heat, air and moisture analysis	Winter 2018
	Evaluate hygrothermal and energy performance	Spring 2019
Demonstrate technology and  commercialize	Conduct controlled field test at CanmetENERGY Ottawa labs	October 2020
	Develop and publish PEER Project Guide to provide step-by-step guidance for panelized retrofits in	Fall 2023

Potential benefits

Recent initiatives in Europe indicate that prefabricated exterior retrofits offer a significant new market. This represents economic opportunities for panelizers and contractors alike. Homeowners and housing providers stand to benefit from reduced operating costs, improved comfort and improved curb appeal. Finally, deep energy retrofits promise to significantly reduce GHG emissions in the existing housing stock.

Results and Outputs

This project concluded in 2023. A field trial was successfully completed on CanmetENERGY’s Ottawa complex in 2017. Two Canadian demonstration projects have since taken place (The Presland PEER pilot by Ottawa Community Housing and the Sundance Cooperative in Edmonton by Butterwick Construction).

The research findings are summarized in the PEER Guide, available for download below. This document provides builders, panel fabricators, design consultants and building capture specialists with step-by-step guidance to carry-out prefabricated (panelized) exterior retrofits. It covers pre-design, building measurement (building capture), panel design, fabrication, and installation processes. This version is limited to prefabricated, above-grade wall retrofits of Part 9 buildings (Housing and Small Buildings) under the National Building Code of Canada (NBC). The intended building typology is multi-family low-rise, though the general concepts may be applicable anywhere from single-family housing to large buildings. The implications of wall retrofits on other enclosure elements such as foundations and roofs, and mechanical and electrical systems are discussed but these other elements are not the focus of this guide.

A Measurement and Verification (M&V) Protocol has also been developed to provide a standard to quantify the impact of deep retrofit (DR) projects, to create a template for monitoring plans and to facilitate uniform and comparable evaluation criteria and data for DR projects for Part 9 and Part 3 Residential Buildings in Canada.

Documents available for download

Individual appendices

Appendix A.1 PEER Wall – Structurally Insulated Panel Wall System
Appendix A.2 PEER Wall – 2x4 Framed Panel Wall System
Appendix A.3 PEER Wall – Nailbase Panel Wall System
Appendix A.4 PEER Wall – I-Joist Framed Panel Wall System
Appendix A.5 PEER Wall – Exterior Insulated Finished System Panel

Contact

For further information, contact Mark Carver, Housing & Buildings R&D, Buildings and Renewables Group, CanmetENERGY: mark.carver@NRCan-RNCan.gc.ca