The Savory House
The Savory House was designed by homeowners with some envelope design and drafting assistance from Montpelier Construction. The house was built by Montpelier Construction with contributions from the homeowners.
Designing and building a High Performing Home, was about more than just energy efficiency for homeowners. The 2100 square foot house was designed for the long term, as a place to raise a family, with forming a connection to the local landscape and deepening ties to the community as important goals. The architectural concept drew inspiration from existing buildings in the area, starting with the basic shape and proportions of the traditional barns prominent in central Vermont. A close examination of the local climate and how it would relate to the energy use and comfort of the house was a critical phase of the design process. Material choices were based not only on aesthetics but were also considered for their traditional ties to the region including locally (and even site milled) flooring and trim, locally milled spruce siding, and honed slate countertops.
Getting to know the building site was an important first step. Camping out on the land, scouting potential timber that could be used for construction and a Solar Pathfinder reading were all part of the initial exploration for Richard and Leah. The sloped site is fairly open to the south and west, which meant they were going to be able to orient the house to take advantage of expansive views to the southwest, as well as make good use of passive solar heat gains through the windows. There ended up being a substantial amount of mature timber on the land as well that the homeowners were able to harvest, have milled on site and ultimately integrate into the build.
Orienting the house to take advantage of passive solar heat gains, was just one of the Passive House principles the homeowners wanted to integrate into the design of their thermal envelope. The design team worked with Montpelier Construction to use Passive House style energy modeling to guide this important part of the design. Projected energy use was modeled at various levels of efficiency and combined with construction cost estimates to determine projected pay-back periods for efficiency upgrades. The resulting thermal envelope was customized to the budget of the project while achieving a level of efficiency well above the norm that also met the requirements of the High Performing Home certification program.
One of the more difficult decisions to make that was going to affect the overall energy use of the building was determining what window manufacturer had the right combination of good thermal performance specs and readily available customer service. In the energy modeling, u-PVC European triple pane windows performed the best when compared to triple pane wood windows made in the US. For this project though, the small yearly energy savings of the better performing window, didn’t seem to justify the increased cost, long lead times and uncertain customer support inherent in ordering from Europe. Marvin triple pane windows made domestically and available through the local lumber yard were a better choice for this project.
The merits of different building assemblies for achieving high R-values were weighed carefully in this stage of the design as well. Different insulation types were chosen for different areas of the thermal envelope from EPS foam under the slab, hydrophobic Rockwool batts on the interior of the foundation walls, a combination of Rockwool batts and dense pack cellulose on the walls, and dense pack cellulose and with a polyisocyanurate rigid insulation ‘over-foam’ approach for the roof. The steeply pitched cathedral ceiling roof assembly was the most challenging envelope assembly both in achieving the high R-values targets and in the actual construction. The ‘over-foam’ approach was determined to be the most cost effective in the design phase, but tough weather conditions made the construction difficult. Despite these challenges, the end result is a high performing climate specific thermal envelope that is expected to use less than half the energy to heat when compared to a code-built home.
In addition to the thermal envelope, material choices and sourcing responsibly was an important ecological consideration. Integrating wood logged and milled from the site was an early goal. Hemlock was the most abundant mature tree species on the land and was an ideal choice for a timber framed second floor system cut by local artisan Dan Von Trapp. A large maple was made into flooring used in the living room which brings character that tells a story including a couple tap holes from an unknown former inhabitant of the land. A massive white pine was made into wide planks used as flooring on the second level. Most of the interior trim on the lower level was made from birch and ash that was also harvested and milled at the site. Working with wood that is harvested and milled on site is a slower and more deliberate process for the builder, but the rewards are well worth it. From grading the lumber to final milling and dimensioning, the building team worked closely with the homeowner to determine where each species of wood would be most useful in the house. The result is an interior that is sure to be a constant reminder of the warmth and beauty as well as utility of the large variety of species of wood that thrive in the mixed forests that make up much of the landscape of Vermont. Other building materials were sourced locally where possible including black locust decking, clear spruce siding from Ward’s Clapboard Mill just down the road and a pine v-groove ceiling milled in Wolcott.
The budget allowed for a strong emphasis on energy efficiency with the understanding that investing in future energy savings was a smart decision. The energy modeling at different levels of efficiency combined with construction cost estimates for each of these levels allowed the homeowners to make sure they weren’t going over board with their upfront investment in efficiency. Triple pane windows, High Performing Home R-values and airtight construction all made sense.
Each design and construction decision for the Johnson-Savory House was thoughtfully worked through. From decisions about windows, to how best to use wood from the land, no stone was left unturned. The result is a home that illustrates how a building can help create a sense of place, responsive to the climate where it is located, made from the same wood as the mixed forest that surrounds it, and built to last well into the future.
