Subdivision in Palo Alto:
The minimum lot size is 6,000 sf with minimum width of 60 feet and a minimum depth of 100 feet.
Detached 2nd Unit: Maximum floor area: 900 sq ft.
Maximum floor area (MFA) and maximum development area (MDA) depend on the degree of the slopes in a property.
MDA needs to take into account of the driveway including a firetruck turnaround area.
Hills are preserved in Los Altos Hills. You can not build your driveway anywhere in your property.
You might only be able to build a home of 5000 sq ft including garage in a one acre lot. Indeed, considering MDA, you might end up with a home of 3600 sq ft.
Be aware of specific setbacks in every side of the lot.
Depends on the location, you might be able to connect with the public sewer. The cost is about $25,000.
When you abandon the septic tank, you have to have the tank removed from the underground and you can leave the pipes as they are before.