In for a dime, in for a dollar.
I only used the SCA for the assignment I posted. Here is my final reconciliation which explains why the SCA is so relaible (in my opinion) and why I didn't feel the need to include the Cost or Income Approach.
Note that I don't say the Cost Approach "isn't applicable" (it is always applicable when the assignment is market value and there are land + improvements to value); the biggest reason not to use it is because the data is so superior in the SCA that the cost approach isn't necessary. My subject's buyer-type is an owner-user; therefore, the income approach isn't necessary (again, IMO).
RECONCILIATION COMMENTS
The sales comparison approach is used and relied upon within this assignment to conclude credible results. In this market, residential properties are purchased primarily for owner-user utility and the sales comparison approach best reflects this market motivation.
The overall quality of the data is very good. There is a model-match that just closed on the same street with a pool. Furthermore, I have another cul-de-sac sale from within the immediate neighborhood as well as competitive sales from the overall competitive market. I was able to confirm the terms/conditions of the sales with at least one agent/broker related to the transaction.
I did not consider this data set to have any significant weaknesses. It provides a very reliable indication of value for this assignment.
The cost approach is not necessary to conclude credible results and is not required by my client. The typical buyer in this market does not consider the alternative of developing a site him/herself vs. purchasing home already built. As noted in the H&BU analysis, it is not financially feasible to develop a vacant site at this time; the lack of feasibility further weakens this approach's reliability. And, last but not least, the data available for the use in the sales comparison approach is so superior that the cost approach would be given little if any consideration, and only in a supporting role. Therefore, the cost approach is not completed.
The income approach is not necessary to conclude credible results and is not required by my client. The subject has been updated and is well maintained; as noted in the H&BU analysis, the typical buyer for this property is an owner-user; owner-users rely on the sales comparison approach as their primary means for evaluating a purchase: income revenue is not a significant owner-user motivation. Therefore, the income approach is not completed.
But, I say again: The entire reason for explaining oneself in the report is so the client/intended user can understand where you are coming from and why you did what you did.
They can always disagree (I'm fine with that as an appraiser). But what I don't want to hear from a client is, "Denis, we don't understand why you did what you did??". If they say that, I've failed to properly communicate my analysis.
(and, you can see one doesn't have to write War & Peace. A short paragraph for each approach should do the trick on most residential assignments).