I would ask for $5,000 if I were you or even $10K if you can get it.Why do people pay such "steep" non refundable option considerations (incorrectly called "downpayment") when they could have paid that and get a bank loan?

Somehow bp propogated something that is not found in any textbook nor taught in any accredited university. 1% or 2% is not always the consideration vs the other primary fundamentals.

One other consideration would be two buy 2 or more properties as your replacements.

I will take that into consideration

As with all lots of residential character there will be a requirement for front, side and rear setbacks resulting in a loss of buildable area further reducing the building size (no permanent structure may be constructed in setbacks)  Depending on city zoning ordinances there may a provision of a zero lot line (meaning possible reduction of side yard setbacks)  with zero lot lines it may be possible to build a  20 foot wide structure, however you may be restricted in height and required to provide additional fire protection between your property and the next.

Is there special consideration I should look for as I add more properties going forward.

Is there special consideration I should look for as I add more properties going forward.

I'm trying to change the pitched roof on a duplex in Newport Beach (Balboa are) to add height and living space for new bathrooms to be added.

Other considerations may be energy efficiency, age, style of the home, functionality, condition, marketability and useful economic life of the entire property.

I will take all advice into consideration when I meet again.