Room Addition vs Room Conversion

  If you are choosing between converting your garage to a Granny Conversion versus adding a room addition, the first thing to determine is to call me or the city to see if the city requires that you have a garage. Most cities require that you have a garage that handles enough cars based on your home’s square footage. If you have a two car garage, and it is required that you have a garage or covered parking, you might have to add a covered parking space or a garage.
   The next thing to determine is if you can add as much square footage as you want because some cities have a limit on how much square footage you can have. There is a setback requirement (how far your addition must be from the property line) and there may be a limit if your addition is adding a second story.
   Converting a room could be cheaper because you already have a slab and walls, but the cost would go up if you need to add a garage.
   You have to ensure the garage is up to where it is suppose to be, meaning you sometimes have to take a few steps back in order to go forward. To bring it up to current code, you may need to strengthen the foundation, pour a thicker slab or modify the tie ins (where walls join to the slab). Strengthening the foundation is also important when adding a second story or converting an attic to a living space with a bath.
   It is probably easier to go with an addition than a remodel, though not necessarily less expensive, because the only unknown can be handled by having the soil tested for how compact the dirt is. There are many unknowns for a conversion. How thick is the concrete slab? Is the framing up to code so it will sustain earthquakes, etc. or do you need to add support framing? Will the city decide that your garage slab is only one inch thick with no foundation around the edges and will they require you tear it down and rebuild it whether you do the conversion or not? Like opening a can of worms.
   In a room addition, you can put all the electric and plumbing right where you want it. Whereas with a room conversion, you have to break into the slab and run plumbing. If your garage has drywall walls, you’d have to break into them to run electrical, and you may need to increase your electrical service by adding a subpanel.
   Once you are past the foundation, framing, electrical and plumbing stage, the finish is very much the same for either an addition or a room conversion.
   All in all, it is pretty much a wash as far as the cost between the two. Whichever you decide to do, call or text me at (818) 613-5632. I can refer an architect or do a bid on your plans. I look forward to doing the job.

- Randy Mate, Ca Lic 978915