These days perhaps the most important consideration in home design and construction is energy efficiency. Once it was common knowledge that the larger the house the more energy it would use, not anymore. Today’s houses can be built comfortably spacious and energy efficient. The greater indoor mass and larger insulated airspace will help a home resist temperature changes and enable it to bank more solar heat without overheating, and then retain the heat farther into the night.

Here are the points that I consider most important in any home building project.

Insulation
By far the most important part of a home’s energy strategy is a robust insulation package. Every exterior surface of a home should be insulated, including basement walls, crawlspace floors, concrete floors in living areas.

Insulation is very cheap in that it will pay for itself, guaranteed. So go beyond the energy code, which was written years ago anyway. At least R19 in sidewalls, and a minimum of R50 over ceilings. Also important is to know that cellulose insulation is significantly more effective than fiberglass in very cold conditions, also it will air seal an area much better than fiberglass, which makes it a better choice for ceiling applications.

Windows
The most common energy problem I see in new home construction is the use of cheap vinyl windows. That is a foolish way to save money. The largest energy drain in a well insulated home is the window area. My advice to clients is to buy lots of windows, buy big windows, and buy good windows. Small windows look horrible from the exterior, and greatly detract from the interior’s look and feel. Now since even good windows have a low R rating compared to an insulated wall, a quality airtight window is important.

A good window will be constructed of clear fir or yellow pine, and clad with vinyl or aluminum on the exterior. The energy ratings for every brand is available on the internet.

Some good brands are Hurd, Pella, Marvin, and Andersen.

Also keep in mind that casements close tighter than double hungs, use fixed glass when possible, and avoid sliding windows as they are seldom tight.

Passive solar heat
Using solar heat to warm a home would seem to be a no brainer here in the Bighorn basin where winter sun is so abundant. Surprisingly none of the new homes around here are designed to use this free, natural heat source. I think the reason is that a passive solar home needs to be designed specifically to each building site. An off the shelf plan or a manufactured home will not be suitable for passive solar. If a builder doesn't have the capability to design housing , then he either hires an architect or doesn't build passive solar housing. Since I design everything I build free of charge, I’m confident that most of my future projects will have some solar heating capacity built in.

Passive solar is a simple concept, here a few design guidelines;

A south facing wall is most important, with abundant glass area, use clear insulated glass, low E glass only allows 20% of solar heat through.

There needs to be roof overhang which will prevent the sun from entering the windows during the summer season, and allow the low angle winter sun to shine as far into the room as possible. My drafting program, Chief Architect, allows me to design this critical element.

There needs to be enough thermal mass in the floor to absorb the sun’s heat. This keeps the room from overheating and allows the floor to bank the heat to help warm the house at night. The larger the thermal mass the better.

My own sunroom is a good example , I excavated about 2 feet lower than the finished floor, then I lined the bottom and sides with 4” of rigid foam insulation, filled the cavity with rock rubble, then poured a concrete floor on top. The concrete is then acid stained a dark color, sealed with acrylic, and waxed. It looks nice, is fairly maintenance free, and absorbs winter sun like crazy. It’s a delight to walk barefoot on it on a cold winter night and feel the warmth from the sun.

Avoid efficiency disasters
Many of my clients insist on having real masonry fireplaces despite my advice to the contrary. These are real works of art especially if done by a master brickie, but they will cost plenty for the life of the house. The masonry conducts heat to the outside and the flue is a heat highway, specially when a fire is lit. I you want to burn wood, place a masonry chimney within the house walls and install an airtight wood stove. This will easily heat a well insulated house when the sun doesn't shine and won't be a heat loss the rest of the time.