Check out this awesome project on Bainbridge Island, WA – One of our favorite parts:
“A roof takes the most abuse of any surface and it has to do a lot of things for you. Overhangs provide shading for windows for example. Its primary task is to keep rain and snow out of the home. It needs to be incredibly durable because it’s getting pounded by everything. Metal is the best material for roofing, with the possible exception of green roofs, and we have that as well. But the primary roof is metal.”
A Big Metal Energy and Water Collector
The metal roof, which runs over the two-story body of the house, was selected to help fulfill those energy and water requirements. “We try to use building materials in ways that are best suited for the materials properties,” McLennan says. “A roof takes the most abuse of any surface and it has to do a lot of things for you. Overhangs provide shading for windows for example. Its primary task is to keep rain and snow out of the home. It needs to be incredibly durable because it’s getting pounded by everything. Metal is the best material for roofing, with the possible exception of green roofs, and we have that as well. But the primary roof is metal.”
The structural standing seam roof from Metal Sales Manufacturing Corp., Louisville, Ky., uses 22-gauge roof panels. The ridge runs east to west, which provides a large southern exposure for a solar array. The eaves drop low enough to provide shading during summer months and allow winter sunlight to warm the house. The mass of the rammed earth structure absorbs the heat and radiates it out during winter.
During summer, that same mass tends to keep the structure cool. The house has no air conditioning and does not need it. The solar array uses photovoltaics that provide electricity for the house and also power the family’s electric cars.
Clean Water Run-off
No building product is isolated. They are all part of a system, and the roof is a very important part of the rainwater system in the house. At Heron Hall, that is especially true since the roof is the main collector for the rainwater collection system that provides 100 percent of the family’s water. To be able to reuse that rainwater, the water shedding from the roof needs to be clean. “Because we also used the roof as a water collection surface,” McLennan says, “it needed to be inherently clean. That means no asphalt shingles, which are loaded with chemicals. And you can’t capture water off a green roof.”
McLennan specified Minneapolis-based Valspar Corp. Fluropon Pure metal coating. “The new Valspar coating,” McLennan says, “was the first coating for a metal roof that is on the DECLARE List of products under the Living Building Challenge.” That means the coating uses none of the chemicals that land on the dreaded Red List of chemicals damaging to the environment and human health, and that Valspar has been transparent about its manufacturing process so buyers can trust its sustainability claims.
Water running off the metal roof is collected in a 15,000 gallon cistern that nestles tightly to the house and fits the salvaged modern aesthetic, especially given the homes natural setting. All water for drinking and other uses comes from the collected rainwater. In fact, the home isn’t even on the municipal sewerage and uses composting toilets.
The McLennan family moved into the house in April 2017 and last month enjoyed its first holiday season.