Greengate Guesthouse in Biwabik

Before. Submitted photo When we chose to build a guest house in 2007, we envisioned a super-efficient, sustainably-built structure that fit in with the farm aesthetic of our historic 13-acre Biwabik homestead. To guide us through the building process, we enrolled in the LEED for Homes pilot program, and will soon become one of the first LEED-certified homes in Minnesota.

LEED (Leadership in Energy and Environmental Design) is a comprehensive green-building program taking home performance to a higher level. LEED-certified homes are designed and built to have a more positive impact on the areas of energy effi ciency, water conservation, indoor air quality, site impact, and materials selection. We were initially drawn to the LEED program because it outlined the fundamental building principles we aimed to achieve, and provided a means to measure and verify how the building performed- in short, we knew LEED certification meant we were ‘walking the walk’.

After. Submitted photo But unlike many projects of this nature, which tend towards space-age designs and often enjoy NASA-level budgets, we set out to show that a highly-efficient LEED home could be economically owner-built, aesthetically pleasing, and very livable. With smart design choices, wise use of local resources, and alot of hard work, we’ve been able to achieve these goals.

Our project actually started with a summer of ‘unbuilding,’ as we deconstructed one of the 70-year old barns on our property. Virtually all of the materials from this structure were saved for later use in the project, and a foundation was built directly on the site of the original barn. By utilizing the existing site, we were able to avoid the destruction of any forest, agricultural or wetlands that commonly occurs with new construction. With the foundation in place, we began construction of a new ‘barn home’ with the same architectural design as the old barn that inspired the project. While still under construction today, we expect to complete the project and achieve LEED Gold certification during the summer of 2010.

Like most high-efficiency homes, Green Gate features a tight, well insulated envelope. Designed to eliminate thermal bridging, a combination of spray foam insulation, dense-packed cellulose and foam sheathing fill the walls and ceiling. Blower-door testing revealed air tightness levels 5-times better than Energy Star standards.

An automated high efficiency HRV (heat recovery ventilator) ensures fresh air exchange inside the tight house, while radiant heat is provided by an electric micro-boiler and infl oor hydronic system. A wood pellet stove is also used for backup heat. A site-built solar thermal system to be installed in 2010 will soon provide heat for domestic hot water and a large fraction of the building’s winter space heating requirements as well.

Other key energy efficient features include triple-paned, gas filled windows, primarily on the south wall for passive solar gain. A Drain Water Heat Recovery (DWHR) unit extracts heat from shower drain water to preheat the incoming well water. A combination of CFL and LED lighting is both inside and outside the house, and key ‘safety’ areas like entry doors and stairs are motion activated.

Strategies to reduce water use both inside and outside the building were also utilized in our project. 100% of the adjacent landscaping is turf-free and requires no watering (or mowing!). Gutters drain to a 1000-gallon storage system to collect summer rainwater for our nearby vegetable and flower gardens, eliminating the need to pump well water for irrigation. Water efficiency measures inside the house include high-efficiency toilets, lowfl ow fixtures, a hot water recirculation system, and a small-scale gray water recycling system.

Non-toxic, recycled, salvaged and local materials were used extensively throughout the project. Nearly 100% of the interior timber framing and millwork is from the salvaged barn wood milled on site. A variety of non-toxic and water-based finishes from AFM Safecoat and Bioshield were used on interior surfaces. 50-year, recycled metal roof shingles were used to replace tradition asphalt shingles. Local, refinished antique furniture were often chosen instead of new. Local stone, slate pavers, salvaged urbanite, tiles and mulch were used for all of the landscaping. The kitchen features Eccorok countertops, FSC-certified formaldehyde-free cabinetry, and higheffi ciency Tier III Energy Star appliances.

As part of our commitment to educate other homeowners about Green Gate’s ‘green’ features, we encourage others to visit our ongoing construction tion blog at www.greengateguesthouse. blogspot.com.