Perched on a bench above Last Chance Gulch in Helena, Montana, Warren house is a test-bed for what we think of as reasonably sustainable architecture. Designed as a retirement home for Habitat X founder Chris Dorsi and his wife Amy Sheppard, Warren house captures many of the best methods and materials that have been identified, fine-tuned, and applied by Habitat Xers over the years. Groundbreaking is scheduled for Summer 2026.

Isometric Views

It’s a modest house with 1024 square feet on each of two floors and a simple rectangular form. The ground floor is dedicated largely to a shop space that supports Chris’ ongoing construction and metalworking projects, an ample mudroom and entryway that reflects Chris and Amy’s outdoorsy lifestyle, and a full bath with a shop washroom. The second floor is all living space with two bedrooms, one bath, and a covered porch. The main living area is a wide open space with interior sight lines of almost 40′ and room to entertain a dozen guests. Strategically placed triple-glazed windows take in a stunning view of downtown Helena and the forested ridges of the nearby Continental Divide.

The building rests upon a frost-protected monolithic concrete slab foundation. The walls are a double-stud wood frame insulated with cellulose and protected with continuous air and vapor barriers. The truss-built shed roof protects a ventilated attic. The walls have calculated values of about R-40 with the attic coming in at about R-80. The air change rate will be a fraction of code requirements, and a heat recovery ventilation system will provide fresh air to the living space. Redundant heat systems, sized to match the micro-load of this super-insulated building, will include a natural-gas fired hydronic system in the floors, and an air-to-air heat pump that can also deliver a modest amount of cooling to the living space.

Ground Floor Plan

Second Floor Plan