Recently I have been thinking about energy issues to do with our future usonian house. I began to do calculations on the amount of energy being lost while heating the home for the year.
I will get more into these calculations later but for now realize that you lose heat through a house’s walls, roof and foundation (and leaks in venting). The more resistance to heat transfer each of these surfaces has, the more energy efficient the house is.
In fact, theoretically you could build a house that can be heated with a candle in the arctic. Now of course there would be no doors or windows or air circulation or anything…
…which brings me to the point of this post. Are we cutting ourselves unnecessarily off from nature in order to save nature?
I mean think about it. Allow me to paraphrase Frank Lloyd Wright; “A house should provide shelter from the elements no more than needed and still promote your access to nature.”
It is what “organic architecture” means.
So this REALLY got me thinking about the amount of windows on the walls of our new usonian home and the balance between connecting with nature and the monthly winter heating bills. Our home’s walls will consist of about 40% double paned glass which is about 16 times less heat resistant than the insulated walls. But I think it is worth it…and can be offset…here is why and how:
- The “gravity heat system” or in floor heating operates at a MUCH lower temperature than the “hot-air-blowing everywhere” system.
- The predominately south-facing windows will create a greenhouse effect in the winter and the floors and brick will store a lot of heat thus helping to take away some of the heating load and variances throughout a day.
- We will be using a geothermal system to help bring the floors up to a temperature of 60 degrees without having to add one BTU of heat to it. So this will reduce the load on the broiler by we believe 1/2 according to studies.
- The surface that loses the most heat is not the walls, it is the roof/ceilings. In our case the most insulation will be in that position (I’m thinking spray foam there up to R56 if we design it as such). Frank Lloyd Wright also theorized that a snow covered roof adds to the over-all insulation value.
- Insulation around and under the foundation will offset a lot of heat loss.
- The house’s concrete and brick will act as a thermal mass storing heat that is normally lost in today’s McMansions. In fact, FLW was known to say you could open all the Usonian house windows in the middle of winter to air the home out and close them awhile later with very little drop in the house temperature. Try that with a forced air gas system.
- No 20% loss of heat through venting because there is none!
The alternative is of course a home which is super energy efficient with few windows and expensive and dishonest materials in the walls.
Everything is a trade off in the world but I do think the windows are worth it. I just can’t picture building a beautiful new home in the country and not being able to see the world around us. Who the heck want’s to live in a windowless box???