I might disagree with Denis that an incentive for an owner occupant buyer is to realize some EI. Imo (usually, or at least in my market ), they choose the more intensive, and perhaps expensive, option of building new vs buying an existing home, either because they want to build their dream home, are architects or designers themselves, or they want a certain kind of home on a site location that is unavailable with existing homes...such as they might buy a 1950's dated but usable home in a fully built out beach side area, tear it down, and build a replica of a bungalow but with modern conveniences...what I call a "vanity house"..... The purchase and cost makes no economic sense but that is not the point, they have the money and EI is not an expectation...they may even lose money building their dream home (at least initially, they might profit later if it's a cool house or values go up)
I'm quoting you here because this is the common path (in my opinion) where many appraisers get sidetracked on the concept of EI.
In your example, you state that an owner-user may go over-the-top to build something for themselves. That is very true.
But (and again for the last time in this thread) plug your over-the-top owner into the position of:
A. Buying an over-the-top home that just happens to be his ideal/perfect custom home
or
B. Building it himself with all the risks, etc.
If he can buy it for the same price as he can build it himself, he will buy it rather than build it.
If he can bu it for slightly more than he can build it himself, he will buy it rather than build it.
Only when it gets to the point that he can build it for less than what it would cost him to buy it ready to go, and at a point where he determines its worth his hassle (risk) to manage it himself, will he opt to do it himself.
The cost approach requires apples for apples: It is the exact same house: build-it-yourself or have it ready-made. In the cost approach, one cannot put
extra money into the one you build-yourself without updating the ready made one to the similar degree.
It really is that simple:
Two homes exactly alike in all regards.
I can buy one for $X and move in.
I can build the same one for the same cost of buying its twin already to go. But if I build it myself, I'm taking on the risk associated with the project and spending the time to do so. When I'm done, it will be exactly like the ready-built home and cost me the same as-if I purchased the ready-built home.
There is no differences in the two choices as far as quality and condition/configuration. They are identical.
There is no difference in the price to acquire and the value of the home: They are identical.
The only difference is for one, it is ready to go without any development risk and waiting. The other one must wait and take on risk of something changing during the construction.
Which one does the rational buyer choose?
Like I said, it isn't that difficult (at least, as far as I'm concerned).
