In 2009 Farr Associates designed a charming two-story, two-unit apartment building, the smallest structure in a larger 43-unit public housing redevelopment in Granite City, IL.  That building was designed to meet the rigorous Enterprise Green Community criteria which set high-performance standards for the building’s envelope. The building walls were 2x6 studs with cellulose insulation and an additional 2” of rigid insulation on the exterior. The windows were fiberglas with triple-glazing. The high efficiency MEP system included a small furnace, hot water heater, and a energy-recovery ventilator.

In 2019, ten years later and one hundred yards to the south, Farr Associates designed a twin to the first building to meet PHIUS + 2018 standards. The building features a higher performing envelope, far more conscientious detailing, and an updated, carbon-free, mechanical system. This represents not only Farr's first certified Passivehaus (PHIUS+ 2018 project, but the state of Illinois' first PHIUS-certified affordable, multifamily housing project! This naturally occurring experiment will provide helpful comparison data for years to come, a significant contribution to building science. 


Client: Granite City Housing Authority

Location: Granite City, IL

Year: 2016

Certification: Enterprise Green Communities funding