If you want to build a Solar or Net-Zero house today, you'll likely encounter this source of frustration: the amount you invest in a PV system will not be reflected in the home's appraised value. In my area, a PV system is given no value (ZERO) by appraisers, even though it has a real asset value of $20-30,000, and it will reduce the home's operating cost by hundreds each month. Why would a speculative homebuilder include solar? The buyer will only be able to borrow up to the appraised value; the builder will be giving away his or her profits by installing PV. Everyone I've talked to in the real estate industry knows about this. The NAHB acknowledges this problem in a page entitled “Valuing Green Homes for What They’re Worth.” Appraisal practices represent a huge barrier to solar energy.
This would seem to be an easy problem to solve. Would you be surprised to learn that it has persisted for nearly 40 years? Here's an excerpt from a 1978 report (referring to solar-thermal heating systems):
"The appraisal of a solar home for purposes of permanent finance is an unresolved issue within the financial community. The builder and purchaser benefit from appraisal practices which include the cost of the solar system in the value of the home.
Lenders report that the most common appraisal technique is the market valuation method, which is based on the sales of comparable units. However, at this time there are few, if any, solar homes in the market area served by local financial institutions. As a result, appraisers have wide discretion in determining value. The diverse practices of the interviewed permanent lenders reflect uncertainty over the question of appraising solar systems."
It is hard to believe that this is still an "unresolved issue"!
Source for quotation: "Building the Solar Home," HUD Report by Dubin-Bloome Associates, 1978.
Update, October 2017: A new Rocky Mountain Institute (RMI) report confirms this problem, saying builders "do not directly benefit from the operational cost savings and have no incentive to maximize them." The solution is called residential property assessed clean energy (R-PACE) financing.