The Architect's Principles for Designing an Efficient House

As stated in earlier posts, it is pretty important to articulate your plan for your home in a written document for all to discuss prior to the start of construction. This helps everyone-owners, builder, plumbing, electrical and mechanical system designers/installers- to understand the end goals and discuss any potential questions and concerns so that they may be resolved with enough time and thought from all. For instance, one of the goals we had was to keep all of our HVAC ducts within the envelope, that is, not a single duct or return in a wall. This wasn't as easy as it might have been for the fact that our bearing wall is our central stairwell, so we had to design some duct chases in interior spaces in both the dining room (we gave up 4") and along the stairwell (which we'd intended to leave open). Because we really liked the layout of our house, these compromises were a small concession to achieving the interior ductwork goal without a significant re-design.

Below are some of the design principles Les Moore (the architect) used to inform his work:

Energy Efficiency Elements

Northern exposure: Garage rear windows at left, to allow for natural light in that space (unheated) and minimum window surfaces on north and East exposures. Small rectangular windows on main house are to provide light under upper kitchen cabinets.

1. The Most Volume for the Least Surface:  The best volume to skin ratio is the first element to consider for an energy efficient house.  A sphere gives you the most enclosure for skin surface, but, as any hippy can tell you, spheres (or their close relative...domes) make very awkward living spaces.  The nearest form to a sphere that can be easily built is a cube...so that's the general form we used for the house.
2. Minimum Interior Volume:  Ceiling heights are minimized to keep the interior volume as small as possible to minimize the heating and cooling loads.
3. Exposure:  Catching and controlling sun while protecting the house from cold and winter winds takes best advantage of the sun's heat. This means maximizing the southern exposure and minimizing the northern exposure of windows and doors.  In cold/icy climates like Syracuse, entrances, entries and garages need to be facing south so that ice can melt on sunny days. Entries with north exposure will remain frozen all winter unless considerable labor or chemical melters are used.
4. Good Insulation:  Lots of good insulation combined with the judicious use of foam to prevent air leakage is the cheapest/best use of material to conserve energy.
5. Good Windows and Door Openings:  Windows and doors must be energy efficient and sized to maximize appropriate sun gain and cold protection.  Generally this means more window area to the south, while minimizing windows on the other faces. Solar "eyebrows" on the south windows, and a pergola on the west main floor (over the deck) will reduce summer heat gain while allowing for optimal sun and some solar gain in the winter. Overhangs are designed to shade from the (at Syracuse) noon sun's 71 degrees on 21 June, but will let in the 25 degrees noon sun rays on 21 December. Additionally, south side window glazing will allow for more heat gain than on the other faces.
6. Solar Systems: To provide areas for solar systems, all the primary roof surfaces (house, entry and garage) are sloped at 45 degrees and face south. The area available for solar panels free of shade and at a reasonably efficient angle for the panels, can provide for both solar hot water (which Lisa and Justin are installing now), and photo voltaic panels (to be added in the future), which ideally will offset a considerable portion of their electric and hot water gas requirements. We used the developer's standard roof truss construction system (a cost saving measure), while also making a house form consistent with its neighboring homes. 

Preliminary sketch for solar shades over main and lower floor south windows

Les notes that when we look at colonial houses in the Northeast many of these natural elements are often applied: minimum space in minimum volumes, taking advantage of southern exposures, while protecting from northern exposures. However, he stresses that while the colonials were saving energy for their own survival, we now need to save energy for global survival.