Mr. Rawlings:
I basically agree with what you have written. I've a few observations to make, not to defend or knock down your premise, but perhaps to add some clarity.
The value of the land and the value of the structure are typically separated in the local county assesors valuations. Local insurance companies also look at these values when they underwrite hazard insurance, as a structure may burn, the but underlying land will not. The insurance companies also look at replacement costs, which is typically a per square foot number when applied to tract homes. This cost will vary depending upon market conditions - costs would have been higher in 2004 at the height of the real estate bubble simply because all the contractors would have already been very busy, as compared to say, today.
Note, however, that assessors values and market values can and almost always do differ in significant amounts.
Valuation a few years ago was much easier, as an appraiser could count on his number being "low" against similar sales in a few weeks or months time. When the market is in decline, as it still is in most of the country, he has to be much more careful, as banks do not want to lend more than the property is worth.
When all the homes are similar the appraiser is working in familiar territory and can establish a value with much more confidence. When the structure is not typical he will by nature want to get more cautious lest he determine a too high value.
That said, there is a market value for a home that is "architect designed". It's a statement that says this is a custom home, not just another out of the tract home mill. Establishing a value for that is difficult, as some will love the design and others will not, much like any tract home. Tell the appraiser that the house is "Rawlings", and thus worth much more than some damn tract house.
For a custom home perhaps the best way to proceed is to find an appraiser that consistently works with higher end homes. He or she will be more aware of non-typical items that can increase the value of an appraisal, including the value of the land it sits on.
I've bought homes as investments, and some investors take the line that the house should appraise for a certain value because they have a buyer willing to pay that amount. Banks will consider that, but also consider that the greater fool theory may be at work.
Appraised value may not completely relate to cost of construction. Probably the best example of this is a swimming pool, which may cost over $20,000 to install, but add only half of that to the homes appraised value. Sadly, this can also apply to the main structure as well.
I wish you well on this.
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Klaus Steinke AIA
Las Vegas NV
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