If its a simple rectangle, 5 ac lot for example, 15% will cover it fine for me.

Having a simple rectangle roof can really keep the costs down on a metal roof as well.

Our current duplex is a simple spanish style rectangle with a footprint of 800 sqft.  

The same two acres, could probably get about 30% more if it was a rectangle versus a square, due to less turnarounds.Attachment:This is a relaxed layout, I did not try to cram the spaces in.Rows and Road ConfigurationARoadBCRoadDERoadFThis layout is on a 2 acre square.Roads are all the same width.All rows are set at 45 degree anglesUnitDescriptionRow: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 notes:If I didn't do back to back would have about 30% less spots ( you have to add more driveways for the same number of units) and payback would be around 18 years versus 12.

It's not worth the cost in this kitchen.2 - Open the entire wall where you want to just open the top of it (blue rectangle), this will be your egress through the kitchen, and move the fridge and stove to where you will...3 - Get rid of that ugly useless peninsula with the red counter top.4 - Fill in the entire opening with a wall where the red countertop peninsula used to be.You now have a galley kitchen, the most efficient design there is of a kitchen. 

Those are NOT the same thing.Look at it this way, "All squares are rectangles, but not all rectangles are squares".

Get the feel of it.  4 acre square, rectangle, other; will determine the number of spots. 

Hey JR, You can actually do this on listsource.com and isolate a neighborhood on a map by drawing a rectangle or circle

I like clean rectangles. 

The building was basically an empty, masonry 2,000 sq/ft rectangle.