We live out of town, on top of the Santa Cruz mountains. This makes a few things easier, we only have Santa Clara County to deal with, no city rules. We also have more space. The downside is that it can be hard to find people to work on the house, and it can cost more to deliver heavy stuff like gravel than it costs to buy it.
The complications start with a scenic highway. We can't build anything within 100ft of the road, Then there is a well, we can't do things within a 100ft radius of that. Then there is a septic tank and leach field. The leach field is two banks of 250ft long buried perforated pipes which occupies a lot of space, including the space that we want to put a garage on. Then a driveway has to find it's way through and have a turn around area big enough to take a fire engine. All of a sudden, a few acres of land is full.
A few years ago we got a plan drawn up for a modified leach field layout. This removed the upper 250ft field so that we could put the garage there, and added a new 250ft field below. To comply with planning rules we had to show that we could on theory add another 500ft of leach field if the first one failed. So that took up almost all the space.
After all that the biggest possible garage we could fit is a free standing building 32ft wide and 36ft deep. It will have one single and one double door and sit alongside the house about 20ft away and slightly downhill.
To prove that the space existed I got my local ground moving specialist Bob Whalen to use an excavator to dig holes and locate the leach field pipes, and made a big flat area in the right place. Along the way we destroyed the upper leach field before I got permission, we got told off but since the rest of the plan made sense we got away with it and were able to move forward.
At some point the county realized that the plan they had for my driveway bore no relation to what had been put in by the people who built the house, this raised the spectre of a grading violation and possible grading permit, which would be needed if we had to move more than 150 cubic yards to get a driveway that conformed to code.
With a lot of help from Terry and crew at TS Civil Engineering we ended up with a plan for the driveway and leach field that met code, didnt raise a violation and didn't need over 100 cubic yards of grading. With a few tweaks the county finally approved the plan.