Building Energy Technology: High-Performance Building Retrofit Options

Fraunhofer Center for Sustainable Energy Systems

Dow Corning vacuum insulation panels (VIPs) are installed at Fraunhofer CSE's field deployment site in Brunswick, ME.

Project Motivation

Retrofits and renovations are an essential, ever-evolving tool in reducing energy consumption in US buildings, particularly older structures. Recent advances in building technology have significantly expanded the options available to homeowners, while manufacturing improvements have made cutting-edge elements more affordable than ever. 


As the availability of energy-efficient systems and materials increases, seeing how they work in real-world situations -- and with one another -- becomes increasingly crucial. Working on behalf of the US Department of Energy, CSE researchers examined two elements in particular: high-performance windows, which minimize heat losses and gains within a building, and vacuum insulation panels (VIPs), a novel insulation material with very low thermal conductivity. 

Proving Durability and Cost-Effectiveness

Following an extensive analysis of the existing structure, CSE's research teams began the process of retrofitting a 1950s slab-on-grade building with new high-efficiency windows and exterior insulation. The main purpose of this retrofit was to prove that high-efficiency windows and vacuum insulation panels could significantly improve the energy performance of old wood-framed buildings in a northern US climate, while simultaneously being durable and cost-competitive retrofit options. To this end, CSE's teams developed a way to integrate high-performance windows with VIP insulation to minimize thermal shorts and long-term durability problems.


Using sensors and other on-site measuring equipment, CSE researchers monitored overall energy consumption, humidity and temperatures along the building envelope for the best part of a year. CSE's findings not only confirmed the insulation value of the VIPs, but also identified potential issues with leakages and air circulation.  


A Building America Project

This assessment work was one of several research projects undertaken by a Fraunhofer CSE-led research team under a task order from the US Department of Energy's Building America Program.