The label (EA, HC) isn't the thing. Only (some) appraisers understand what those labels actually mean. Nobody else knows or cares about the labels. What's important is what you (SR1) do and how you (SR2)disclose the additional assumptions and limitations of what you did. And then provide the (SR2) warning to the reader that if some aspect of the SR1 scenario occurs differently it would have an effect on your opinions and conclusions.
The effective date isn't always the date of inspection. Appraisers do retrospective on a regular basis for certain situations like date of death or prior to the earthquake or whatnot. Same can occur when the question is what the property will be worth when a proposed or potential something is expected to occur by some date in the future.
---------------------
For an existing use/condition the Prospective includes some variables
1. What that future date is (for an existing use/condition the client will probably pick that date for whatever reason they have for asking for a future value)
2. What the pricing trends will do between now and that future date
3. How those pricing trends will change the current value
If this is a single family, the appraiser's only way to do this is to take the current value and project it into the future based on recent and current trends or whatever the appraiser thinks it will be. Usually and in lieu of info to the contrary the appraiser can extrapolate the recent past/present trends into the future. But that isn't the only possibility.
----------------------
Then when there's a "subject to" that changes the subject property attributes you still have all of the same variables that apply when there is no anticipated change to the subject attributes, but are adding a couple more variables:
4. That the work will be completed as of a specific date (which the appraiser may be the one forecasting when the project is complete)
5. That the work will be completed per plans and specs because if it isn't then that will affect the appraiser's opinions and conclusions
One wrinkle they never mention is that you basically cannot get to what this altered subject will be worth in the future without starting with what it would be worth today. That's why I always add a 3rd valuation scenario "subject to/current date" whether they ask for it or not.
"As Is / Current Date"
"Subject To Completion / Current Date"
"Subject To Completion / Future Date"
In that manner I am conveying the effect of the changes to the property (which is knowable as of today) separately from the effect on value of the future market trends (which is unknowable as of today).
I also build 3 projections of that future value - based on different assumptions for the pricing trends during the interim - before reconciling to one of them as my own conclusion. That way the reader can get an idea of what else might happen if the scenario I concluded to doesn't work out.
"The market trends over the last 2 years have shown moderate increases averaging ~6%/year.
A- If the rate of increase stops at 0%/yr then the 03/2026 value will be similar to the current 03/2025 value. $500k x 1.00 = $500k
B- If the rate of increase slows to 3%/yr then the 03/2026 value will be slightly higher than the 03/2025 value. $500k x 1.03 = $515k
C- If the rate of increase remains at 6%/yr then the 03/2026 value will be markedly higher than the 03/2025 value. $500k x 1.06 = $530k
In lieu of information or indications to the contrary I have projected the recent/current trends into the future (#C above) so in my opinion the future value as of 03/2026 will be $530,000.
This opinion of the future value (aka prospective value) is based in part on the assumptions that the improvements will be completed by then and the market trends don't change over the next 12 months. In the event that any of these assumptions are not met in full it would have an effect on my opinions and conclusions."
Obviously, the above isn't the only way to get to a prospective value for a construction related project, but it is one way to do it. YMMV.