Gail Mercedes Cole
Your Westside Homes
1st you need to get plans and then a solid contractor. Since we are general we can take care of everything and manage your project with our in house crews. We do great work. #1 in los angeles. Ask around and call us now for a free estimate 855-247-6225 http://www.socalpb.com
You will have to make sure your garage meets current setback requirements. 3 feet on the side 5 feet on the back (to the lot line)... also you may not be able to building a complete dwelling if your zoning only permits 1 dwelling per lot.. unless your lot is over 7500 sq ft.
There are lots of things to consider and a trip to the city building and safety counter can make things clear for you.