In a hypothetical $150,000 new construction project, my experience suggests that passive solar design and construction might cost and added $22,500 (15%). And based upon our experience, such a structure should require less than 50% of the heating costs of a conventional home. Assuming a conventional heating budget of $700.00/yr, this suggests an annual savings of $350 or 1.5%/yr of the costs of the passive solar components.
|1/11/01 Some of the data suggests that the energy savings from passive solar heating might be twice as high as the above numbers. I would rather underestimate the benefits and avoid the type of unrealistic and damaging 'hype' that accompanied passive solar information in the early 80's.|
1.5%/yr is a relatively poor return on investment. But a passive solar home has some additional advantages:
And passive solar design and construction is not an 'all or nothing' proposition. It can start with the selection of a lot and building site with a good southern orientation. Increasing glazing on the south side, and decreasing glazing on the north side can help. Placing the garage on the cold side of the house and the living spaces on the south side will also help. Each of these and many other small steps can start to transform a house into more energy efficient and pleasant home.