Wall Upgrades for Residential Deep Energy Retrofits: A Literature Review

Abstract

In the United States, 39% of total energy is consumed by the building sector, 20% of the total is attributed to residential buildings (U.S. Energy Information Administration, 2018). New, highperformance homes incorporate a combination of tight building envelopes, mechanical ventilation, and efficient components to ensure comfort, adequate airflow, and moisture control. These systems work together to create energy efficient homes that use measures to manage moisture, comfort, energy efficiency, and the indoor environment. Older homes, built before 1992 when the U.S. Department of Energy's Building Energy Codes Program was established represent approximately 68% of residential building stock in the country and often have significant air leakage and inadequate insulation. Homes with little to no air sealing or insulation have heating and cooling losses that can represent a substantial portion of utility bills. Done correctly, deep energy retrofits can significantly improve the energy performance of a home's thermal envelope, and increase homeowner comfort and health. This literature review summarizes current practices for exterior wall retrofits for existing homes, provides an overview of techno-economic approaches to investigating residential wall systems, and discusses thermal and hygrothermal modeling strategies. This literature review is part of a larger effort to identify state-of-the-art technologies for energy efficient wall retrofit systems that are suitable for cold and very cold climate zones. Retrofit wall systems that can be applied over existing siding offer a possible approach to reducing installation costs.

Home Energy Upgrades as a Pathway to Home Decarbonization in the US: A Literature Review

“…Above grade wall insulation upgrades, which include insulation placed on the exterior of the structural sheathing (and sometimes within framing cavities, as well), have received substantial attention in the research literature. Pacific Northwest National Laboratory (PNNL) has produced an extensive review of wall insulation upgrade costs, material and methods for residential buildings in the US [79]. The typical costs and cost ranges from our review of this literature are shown in Table 2.…”

“…Earth Advantage Institute [78] has documented incremental costs of only USD 47 per m 2 (USD 4.35 per ft 2 ) for this application with 1" of exterior foam insulation, though costs remain fairly high and the construction workforce is not familiar with the methods and materials. has produced an extensive review of wall insulation upgrade costs, material and methods for residential buildings in the US [79]. The typical costs and cost ranges from our review of this literature are shown in Table 2.…”

Beyond Operational Energy Efficiency: A Balanced Sustainability Index from a Life Cycle Consideration

“…Consequently, around 75% of the existing building stock in the European Union (EU) is energy inefficient [2]. In the United States, most existing houses were built before the establishment of the Building Energy Codes Program in 1992 by the U.S. Department of Energy, Washington, DC, United States [3]. These older buildings represent about 68% of the national residential building stock and are typically energy inefficient due to air leakage and inadequate insulation [2].…”