I understand that Zillow's algorithms use information from areas that may over-extend the boundaries of the primary area of sale to come up with an estimated sales price.

@Terry Burger , For a "regular" house on a "regular" lot your looking about 7 bucks a foot +/-    For this type of situation I would consult with the municipality, my engineer and my plumber on the EXACT parcel of land I was looking to develop.  

This allows you to borrow all of the payment/transaction history (which is roughly 35% of the weight to your FICO algorithm/score) all the way back to when the card was opened.

I wouldn't use their algorithm solely to rely on a value of the property.

Had an interesting discussing at the Orange County BP Meetup (everyone should come) with an engineer that deals with solar projects.

I am a licensed PE in CA.

Development is a very complex business that involves real estate, construction, engineering, design, finance, etc.

Now that the easy part is over (yes, that was the easy part) you will need to research SEO or Search Engine Optimization.

@Mike Mitchell Techniques such as direct mail, craigslist ads, networking with realtors, pay-per-click, search engine optimization, and bandit signs (check your local area to see if they are legal).

What would be the all included (engineering, permits, materials, labor,...)sqft construction cost on a $/sqft basis for the such a project excluding land?