It is easy to see why many appraisers interpret these two words to mean the same thing. Here are the definitions of both words as presented in Real Estate Appraisal Terminology by Byrl N. Boyce of the former appraisal organization known as the Society of Real Estate Appraisers.
Overimprovement- An improvement which is not the most profitable for the site on which it is placed because of its excessive size or cost, and consequent inability to develop the maximum possible land value. May be temporary or permanent.
An overimprovement typically reflects environmental obsolescence, although a substantial market may exist for such property among a group which takes personal pride in owning the most expensive home in the block and is willing to pay a price commensurate with cost.
Superadequacy- A greater capacity or quality in a structure or one of its components than the prudent purchaser or owner would include or would pay for in the particular type of structure under current market conditions.
[Thus] an over-improvement would be external (environmental?) obsolescence .... instead of a super-adequacy which suggests only a component or components of that improvements were excess to the market "norm."
I like that distinction, and I think it would answer the questions I asked weeks ago. I should have reflected an external obsolescence, because if the dwelling was in the appropriate neighborhood (the other side of county, lakeside, etc.) there would be no items super-adequate. I.e.- a $40,000 chandilier is super-adequate in most markets, but a new home in the slums is an over-improvement.
Terrel
It seems like a minor point what you call the source of the excess, just so you recognize and account for the excess, but on the other hand words mean things and it is best to preserve the language. In my mind over-improvement relates to highest and best use. It has the connotation of a loss in value due to a lack of conformity or harmony with the neighborhood norm. The total property is above the neighborhood norm.
On the other hand, super adequate means an excess of something. A foundation that will support double the required load, fixtures whose quality far exceeds the standards required, over sized hvac capacity, excessive bath fixtures like his and her toilets side-by-side ( I still can’t figure that one out). , etc.
If you look at it this way, it is clear that two standards of measurement are involved. Over-improvement is a total property concept and super adequate is a value factor concept. One is a measure of a residual and the other the difference between the excess less the standard. It is macro vs micro. Or so it seems to me.
I blocked, copied and pasted it into WP and then edited it a bit.
