Here at Gimme Shelter during this wonderful Midwestern spring, we are wrapping up a variety of winter projects that represent some of the many opportunities and challenges that come our way through our diverse and discriminating clients.
We have spent much of the winter months working with the delightful Order of Julian of Norwich, an Episcopalian Monastic Order, creating a place of reflection in Northeastern Wisconsin.
We entered into a design process with the Sisters in early 2016. Our goal was to expand the lodging and communal space at their newly acquired Home in White Lake, Wisconsin. The Sisters came to the design process having experienced extensive work upgrading their previous residence in Southeastern Wisconsin. Their mission includes a commitment to sustainability and this shared commitment guided our design process. Below is a discussion we shared with the Sisters and their supporters explaining our design and construction process:
Energy Efficiency, Design and Sustainability
The Guesthouse Wing for the Order provides an opportunity to consider the integration of energy efficiency, design and sustainability in the context of contemporary understanding of building science and environmental awareness.
Energy Efficiency is a baseline expectation for us. We understand that the building envelope has to be understood as a balanced system in terms of the relative levels of performance in the floors, walls and ceilings. Keeping that in mind, we want the floors, walls, windows, and ceilings to have similar levels of thermal performance. This is somewhat affected by cost benefit considerations.
For example, higher levels of insulation in the ceilings are relatively inexpensive compared with achieving those same levels in the walls. In the case of the guest wing, we are building to the following levels of performance: Floors will be R20, Walls R30, Ceilings R70 and the Windows R5 (window R value will vary as south windows will have a lower R value in order to have a higher solar heat gain). Insulation values, by themselves, are only a part of the overall thermal performance characteristics of the building. Air sealing or air tightness is equally important.
We understand that there needs to be a consistent strategy to provide a high level of air sealing. Our strategy involves using “smart” vapor control membrane (Intello) combined with tapes and sealants to seal all plumbing and electrical openings as well as with the window and door penetrations. This attention to air sealing means that we can receive the full benefit of the insulation we are installing, while ensuring the long term structural integrity of the building.
The design process begins with an understanding of the value of simplicity as a design concept. When we create simple somewhat rectangular shapes on an east west axis, we are responding to our climate and our seasonal exposure to the solar cycle. We can favor south facing windows for their day lighting, ventilation and views, and offset their relatively poor thermal performance with the thermal gain they provide during our heating season. In the case of the Guest House Wing, we were able to position the structure so that we could place the majority of the window glazing facing to the south looking through the west yard.
Sustainability is a concept that can have many levels of understanding. First, we want to create safe and healthy environments. This means ensuring that the inhabitants have adequate and efficient ventilation and we choose materials and finishes that have low or no volatile organic compounds (VOC). In the case of the Guesthouse, we will be using heat recovery ventilation (HRV); a strategy in which heat or cold is extracted from exhaust air and is used to temper incoming air. We will use hard surface flooring, rather than carpeting and low or no VOC finishes and materials.
We want to build buildings that are emotionally satisfying. When we are successful, we increase the chances that these buildings will be long lived and will thereby help justify the resources consumed in their construction.
We also consider the environmental impact of the materials we use, for example, we favor cellulose insulation in the walls and ceilings and EPS foam subslab because of the low global warming impact and high performance profiles of these products compared with extruded or sprayed foam or fiberglass.
The Guesthouse walls, floors and roof are sheathed in native white pine lumber provided by the internationally acclaimed 150 year old sustainable forestry efforts of Menominee Tribal Enterprises. We choose this material for its sustainable source, and also for its high level of durability; especially when we compare it to typical modern choices of manufactured sheet goods like OSB or plywood. Other material and finish choices are driven by that mix of environmental impact and durability, sometimes referred to as Life Cycle assessment, are standing seam steel roofs, LP SmartSiding, and thin coat plaster.
The creation of the Guesthouse wing also prompted several significant upgrades to the existing systems in the original house. The boiler and furnace were replaced with state of the art condensing modulating units, the outdoor smoky and inefficient wood fired boiler was replaced with a European style Masonry Wood Stove complete with indirectly fired bake oven and a generous heated bench. The original improperly ducted, and thus poorly performing, bath vents were replaced with a more robust central vent system.
The design and construction of the Guest House wing has been a great shared experience with the Sisters, and we hope that it will provide a nurturing space for the Sisters and their associates for many years.