Hjälmaren

My house is built in an unusual manner, and many have asked me to explain it in a little detail. This page is an attempt to do that. The name, by the way, is a very obscure joke that I hope someone, someday, will get.

Environment

The house is on the midcoast of Maine, on a tidal river, a dozen miles from the ocean. The climate is zone 5. The latitude is 44°N. It is nestled into the south side of a small hill at an elevation of about 50 feet. The climate here is temperate with cool summers (< 90°F) and cold winters.

Objectives

I hoped to construct a house which would have a minimal impact on this beautiful environment. That meant among other things as little introduction of poisons as I could manage, energy efficiency, low embodied energy construction materials, and beauty. That last, as I understand that the most green building possible is wasted if it is torn down because no one wants to live in it. Whereas Fallingwater is a house so pretty that people are still paying large sums to maintain it despite nobody wanting to live in it. It was occupied for only a few years (Dec 1937 - 1940).

Design

The house is a high post cape, with a timber frame covered by a 12 inch thick Larsen truss. The inside dimensions are 24 feet by 36 feet. The model shown, is part of the design process I used. Not being good at visualizing, I made a computer model of my thoughts for a house on a program called Bryce 5. It was very useful for determining how things would look, and making small changes. For instance, I found that moving the windows by a couple of inches was enough to change the house from looking 'wrong' to 'right'.

The design is available as a Sketchup model

Interior

The interior is an open plan with few walls in the first floor, and (currently) no attic, thus all upstairs rooms have cathedral ceilings.

The timber frame posts in the interior could have been avoided, however, I am glad I didn't. The posts define the space. They separate the various functions, provide a path from one end of the house to the other, and allow furniture to be place against them without looking stupid.

Failures

Front door

I wanted a wood front door, because I like the appearance. I left the choice of door companies up to my builder, so I got a cheap door. In the first winter, due to the high humidity in the house, the door sweated, causing the weather stripping at the bottom of the door to freeze, bind, and eventually, to fail completely. Since the R-value of wet wood is practically nil, I lost a lot of heat through the door. I have since dried out the door, sealed with high quality oil-based paint, re-weatherstripped and gotten something only slightly better looking than the fiberglass door that I perhaps, should have gotten at the start.

In an effort to fix this front door, I have since put a wooden storm door on the outside, and built insulated panels for the inside (read the story here). Without these, the front door represented 5% of the total heat loss of the building.

Insulation around windows

My builder shoved fiberglass insulation into the gap between the window and the rough opening. This is standard practice, and although my situation was extreme, I can't help but believe that everyone must suffer from this practice. What happened was that, I do not yet have trim boards over that gap, so air moved through the fiberglass and the vapor condensed and then froze. So I had fiberglass reinforced ice around all my windows. I was forced to remove it all with ice picks and heat guns, and replace with expanding foam. I attempted to use latex foam at first, but it never dried due to the moist conditions. Polyurethane foam is water cured and worked great. In my opinion, all houses should be using foam in this application.

Bulkhead

A standard bulkhead is a disaster (as far as I can tell) from an energy perspective. It is a large steel door with no insulation, no weather stripping, no locking mechanism to speak of. Mine leaks both air and water. I have made adjustments to mine to make it tolerable. Namely, complete weather stripping, a system (rope) for closing it tightly against that weather stripping, and then sealing it off behind 4 inches of foam insulation board (R-20). The insulation sits on the first step, and boards installed along the sides at the same height, and then there is an interlocking cover in the front. My builder recommended this design over just covering the doorway in the basement, because he said that it could cause the bulkhead concrete to freeze and crack away from the basement walls.

What I should have done was to put in a walk out basement door. I did not because my general contractor said that it would cause grading problems. Turns out he was wrong about that.

Insulation settling

In 02008, I was able to examine the entire house with a borrowed infrared camera. Doing so pointed up many places where the insulation had settled (or never got) and there were now gaps in the insulation coverage. This required reapplying insulation (blown in from the inside). I would recommend anyone using trusses to use wood I-beams with a solid webbing to keep insulation from migrating during application. In addition, I would recommend a dense pack process.

Successes

Light

One unexpected benefit of the house design, is the extraordinary qualities of light throughout the house. With the open plan, the sunlight can pass through the entire house illuminating unexpected places. Two days a year, the sun sets directly down the line of the house, bouncing from one window back to the one where the light came in. Very cool.

Energy

The house consumes very little energy. Heat is accomplished with a heat pump and about ½ cords of wood. All energy is total 4,482 (was 9,927 when the house was first built; improvements happen) purchased BTUs / (heating + cooling) degree days. If you want to see how your house compares, you can use this Calculator