Fifteen miles southeast of Steamboat, Colorado, within a residential development divided into 35–40 acre parcels will soon be an off-the-grid home known as the Blacktail Residence. Because of the size of the property, there’s an abundance of material on-site to burn to heat the home, and to take advantage of the views and the privacy on the property, the owners chose to have their home positioned at the top of a steep ridge rather than lower on the land. Keith Kelly, a principal at Kelly & Stone Architects says this choice has been a significant driver in the design.
The homeowners of the Blacktail Residence wanted a low-energy, self-sustaining home and hoped to achieve a sub-30 HERS rating. Various systems, including those for water capture and storage, have been explored—a task that’s been a challenge, Kelly says, as the owners requested each system be proven effective prior to installation. Plus, with Steamboat’s late-in-the-day summer sun, the heat liability was another obstacle the home’s structure and materials would need to resolve.
To begin, Kelly & Stone Architects brought in an energy consultant to conduct energy modeling. A 3-D model of the home was created to assist with heat-load calculations and assemblies, prompting the incorporation of deep overhangs and window shading, in order to minimize late-day heat gain caused by the west-facing façade. Triple-glazed openings for the windows and doors also will improve the home’s efficiency.
Taking advantage of all that sunlight, the home will use hot-water solar and photovoltaic systems. Its extremely efficient thermal envelope is designed to reach between R-80 and R-100 in the roof and up to R-45 in the walls. Another request was a multifuel boiler, something Kelly & Stone Architects hadn’t used before. “It has a wood-burning combustion chamber that is also tied into a liquid propane burner,” explains principal Tim Stone. “When wood isn’t burning, … and it calls for heat, the gas burner takes over.”
Though there’s power within reach of the Blacktail Residence, the homeowners are determined to operate off the grid. This decision has financial benefits: Stone says the utility lateral across the parcel is rather far, and a lot of the alternative-energy systems’ costs will be recouped if utilities aren’t installed.