Remember that most construction projects require approval from the city of Irvine's Community Development Department. They are the ones that handle planning, permits and code enforcement.
Some ideas to consider.
Reroof: You will need to provide the city with the fire proof code of the material you wish to use. The city does not allow reroofing with shake anymore.
Construction: Make sure that you have your Title XIV study done. This study looks into energy efficiency and so on.
Fences: Be mindful of sightlines. The City can be touchy
about them.