Should I scrap it and start new or renovate and add a 2nd level?

[Tyron McDaniel]

I really hate tearing down old structures but I have this corner lot and this 1,000 sq ft storefront is in much worse condition that this picture shows. It's currently set up as a (2) storefront like spaces just over 500 sq. ft each.

Rather than scrapping it, I am thinking of adding a 2nd level 3 bedroom unit so that you now have a fully functioning business space and an attached but seperate house. Ideal for business owners and people who work from home and because of the close proximity to downtown Houston I am thinking this could be a neat property! 

Have any of you renovated a property where the initial structure wasn't in great shape and you added a 2nd level? Did you regret not scrapping it and starting fresh? Obviously I could do that but I just hate tearing down older properties... (weird I know) - it's my inner tree hugger! 

[J Scott]

We've done both -- repaired and added-on square footage and tear-downs...

What are the numbers?  What is the time savings by not tearing down?

Those are the two pertinent questions...