Bozeman Cohousing, located on 5.3 acres in Bozeman, Montana, is the first certified net zero energy cohousing community in the United States and the first of its kind in Montana. Comprising 43 homes and extensive shared spaces, the project was developed with the aim of integrating sustainable architecture, affordability, and social equity within a cooperative framework.
Community-centred design
The project was realised through a participatory process led by Studio Co Hab, engaging future residents in workshops and consensus-based design sessions. This collaboration ensured that every aspect of the community, from urban layout to material selection, reflected residents’ shared values.
The site plan prioritises walkability and social connection. Parking is placed at the periphery, leaving the interior pedestrian-only, where landscaped paths and courtyards promote interaction and safety. The 43 units are arranged into four ‘pods’, each with its own architectural character, fostering smaller community clusters within the larger whole. Homes range from 576-square-foot studios to 1,450-square-foot three-bedrooms, with universal design and ageing-in-place principles integrated across all layouts.
Affordability was addressed through spatial efficiency and community-driven funding models. Compact footprints, multi-family typologies, and shared amenities reduce construction and operational costs. Two permanently affordable homes were created through a resident-led subsidy fund, matched by city housing grants.
Sustainability and building performance
Sustainability guided every design and engineering decision. The community achieves net zero energy through a combination of super-insulated envelopes, airtight construction, heat pump systems, and on-site solar generation.
Each building employs ZIP System R-12 sheathing for continuous insulation and air-sealing, complemented by high-performance windows for thermal performance and daylighting. Blower-door tests confirmed an average air-tightness level of 1.0 ACH, exceeding Passive House requirements.
All homes and shared facilities are fully electric. Heat pump water heaters and heat pump dryers further reduce operational energy, while shared water-heating systems between units lower total equipment loads.
On-site energy is produced by solar PV arrays that offset 90–105 percent of the community’s total energy demand, achieving a modelled energy-use intensity (EUI) of 16 kBTU/sf/year, well below Passive House benchmarks.
Innovative passive systems further reduce reliance on mechanical systems. A 2,000-square-foot shared sunspace with skylights acts as a passive solar collector and thermal buffer. Natural ventilation and a downdraft cooling tower—the first of its kind in a cold climate—provide seasonal comfort without air conditioning.
Materials and carbon reduction
The project minimises embodied carbon by reducing concrete use in foundations and site paving. A permeable grass-reinforcement system replaces roughly half of the asphalt typically used in fire lanes and parking. Sustainable finishes include wood-core flooring, paper-composite countertops in common spaces, and community-built dining tables crafted from reclaimed site timber.
An independent study by Professor Jesse Sherry (Eckerd College) found that Bozeman Cohousing residents’ per-capita building carbon footprint is 1.6 tCO₂e per year, around half the state average. Including solar offsets, operational emissions drop to roughly 10 percent of the Montana average.
Sustainable mobility
The project’s infill location allows most residents to walk or cycle to schools and Montana State University. Every covered parking space includes Level 2 EV charging, supporting an EV ownership rate far higher than the state average.
