New Market Opportunities for High-Performance Envelope Retrofits

Josh Quinnell, Ph.D.

Why This Research Is Needed

Heat loss through the envelope of existing single-family homes is the largest energy burden faced by buildings in Minnesota. This market study will define enhanced envelope retrofit packages and identify opportunities to strategically leverage existing market channels to reduce these envelope losses. Single-family home construction in Minnesota uses more than double the energy for space heating than the national average, because Minnesota has more cold days. While the advent of the statewide energy code in 1976 has led to dramatically reduced loads on new construction, over 55% of all homes today were built before that, and 85% were built before 1990, when builders began to seriously consider air tightness. Envelope upgrades that bring the existing residential buildings up to the insulation and air tightness levels prescribed by current code represent the largest building energy efficiency opportunity in Minnesota.

Project Process and Expected Outcomes

This study will identify and quantify new opportunities and market channels that can incorporate existing residence envelope retrofits at lower incremental cost, thereby offering existing buildings a feasible pathway to high performance. This proposed work will determine the efficiency potential and market characteristics of these retrofit opportunities. In particular, this study will assess bulk retrofit opportunities with housing authorities, as well as potential new channels including time-of-sale or time-of-renovation markets, and on-bill or long-term financing. The study will quantify the ability to leverage these opportunities and improve the cost effectiveness of high-performance envelope retrofits.

This project is supported by a grant from the Minnesota Department of Commerce, Division of Energy Resources through the Conservation Applied Research and Development (CARD) program, which is funded by Minnesota ratepayers.

Project Info


April 2019–September 2020 


The goal of this project is to complete an assessment of opportunities for state-of-the-art, high-performance envelope retrofits on existing single-family homes.

Non-Energy Benefits

Increased home value. Lower default risk. Improved comfort and indoor air quality.


Assessment and analysis of enhanced envelope upgrades. At least 50 interviews with practitioners in relevant fields. Suggest market opportunities and pathways forward based on research results. Incorporate and collaborate with ongoing national work. 

Josh Quinnell, PhD