Does asphalt vs. concrete matter much, and does the condition impact appraisal value?

Additionally you might need to "pound the pavement" locally and hand out fliers to talk with business owners and managers if they would want to move to your location etc.  

I can not pound the pavement enough and they serve as a good way to get basic info on properties.

Then another cost to restore the asphalt.

I'd add that it is not just the monthly HOA, but all the SPECIAL assessments that occur; exterior paint, pool repairs, fencing, asphalt parking and roof replacement for just a few.

My roof is 4 years old asphalt shingles and my insurer is Lloyd's of London.

You’ll need to confirm the setback requirements, the acceptable age of the homes, and the required permits.4) Other infrastructure:  You may need to prepare the home site, lay concrete/asphalt parking pads, remove trees, add drainage trenches, and otherwise develop the land to accommodate the homes.Executing this type of project can add significant value to your property but you must have a reasonable belief that you can earn enough after factoring in the $20k+ investment required per lot to create the new living space.

Asphalt shingles leach material during rain storms, and can leach material not great for ground water. 

I am going to be using LP smartside instead of vinyl siding which is going to cost an extra $3,000-$4,000.I suppose when I build a spec house I would opt for asphalt shingles ($1.50/square foot) and do good double pane windows for half the cost of triple pane and still have it be good quality, energy efficient, and attractive.  

If I were you I would start pounding the pavement and talking to people in the neighborhoods where these run down properties are located.