REALIZE Zero Carbon Deep Energy Retrofit Case Study

The Hano Homes project in Boston aims to transform a multifamily residential building constructed in 1888 into a net-zero energy property through a deep energy retrofit planned for 2023–2024. The strategy involves wrapping the building in a superinsulated exterior shell, replacing gas boilers and water heaters with all-electric heat pump systems, and installing a 100–110 kW rooftop solar PV system. These measures are expected to reduce energy usage by 69% and eliminate operational greenhouse gas emissions, while the use of bio-based insulation is intended to store carbon and reduce embodied emissions.

• The retrofit is projected to reduce the building's energy use intensity (EUI) from 75.2 kBtu/sf to 23.2 kBtu/sf, representing a 69 percent reduction in energy usage through electrification and efficiency.
• The project aims for net-zero operational energy by installing a 100–110 kW rooftop solar PV system, which is expected to serve 100 percent of the total load and save $43,566 in annual utility costs.
• The building envelope will be upgraded to a superinsulated skin, increasing wall thermal resistance from R-10 to R-36.8 and roof resistance from R-20 to R-59.1, utilizing 8 inches of carbon-storing wood fiber insulation.
• All fossil fuel systems will be replaced with electric alternatives, including heat pump water heaters and decentralized Minotair Pentacare V12 units that provide combined heating, cooling, ventilation, and filtration.
• The anticipated hard construction cost for the deep energy retrofit is $3,039,995, which averages to $122 per square foot of floor area or $152,000 per apartment.

APA

RMI (n.d.). REALIZE Zero Carbon Deep Energy Retrofit Case Study. https://rmi.org/app/uploads/2023/02/hano_homes_case_study.pdf

Chicago

RMI. REALIZE Zero Carbon Deep Energy Retrofit Case Study. n.d. https://rmi.org/app/uploads/2023/02/hano_homes_case_study.pdf.

Wikipedia

{{cite report |author=RMI |title=REALIZE Zero Carbon Deep Energy Retrofit Case Study |url=https://rmi.org/app/uploads/2023/02/hano_homes_case_study.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{rmindrealize, author = {{RMI}}, title = {{REALIZE Zero Carbon Deep Energy Retrofit Case Study}}, institution = {RMI}, url = {https://rmi.org/app/uploads/2023/02/hano_homes_case_study.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }