The comps will be from high prominent neighborhoods, larger square footage properties and not accounting for adjustments, distance of comps is way off and when appraisal comes back wants to cry foul.

Its a 3/2 with larger square footage located on a busy convient road connecting to all shops.

It was a borderline mansion in terms of rooms and square footage, but didn't have a view or anything.

As far as houses with horrible additions, I typically offer less for those to account for the costs of removal of the addition and the loss of square footage on the final price.I would recommend:1.

I have not looked at past 10 year appreciation but, for example, a similar floor-plan home (square footage lower by 40sqft but plot size bigger by 1000 sqft) which is 2 houses down got sold for 620K last year.

The total square footage is roughly 700 sq ft.

Building a greater amount of square footage on a lot all at once will likely lower the avg cost/sq ft for your project, but since you would be building multiple dwelling units (each with their own kitchen, bathrooms, utilities, etc.), the cost/sq ft is definitely going to be higher than if you just built a massive SFR on the lot. 

(but still trying to find exact sq footage requirements)3.

Here's their current top 6 city mix: 12 APEX 27 CARY 13 FUQUAY VARINA 14 HOLLY SPRINGS 103 RALEIGH 24 WAKE FORESTThe average square footage is 2096 sq.ft, and their average purchase price is about $268,341.

I recently spoke to one of my appraisers who informed me that though you may increase livable square footage with a garage conversion you actually run the risk of decreasing value of the property by eliminating the garage.