How Much Does a Room Addition Cost in Los Angeles?

Most people are familiar with the famous quote from J.P. Morgan (1837-1913) the famed financier and banker who said, “If you have to ask how much it costs, you can’t afford it”. While that quote may apply to yachts and the envied top 1%, even Mr. Morgan would have wanted to know how much it would cost him to add a room to his mansion. And for the common person, it is imperative to get a cost estimate on any construction project such as a room addition.

Determining the cost to add a room in the Los Angeles area is a two-step process

The first step is the actual construction of the walls, windows, doors and ceilings. The second step will depend on if you are adding a bathroom, kitchen, small sunroom, large bedroom, office or recreational area and what features and furnishings will go into the new room.

If you hire a qualified room addition contractor, the average cost in the Los Angeles area will be around $200 to $220 per square foot of added space

This means that a 300 square foot addition will cost you about $60,000 before any features are added to the room. The $60,000 cost should include laying the new foundation, framing, windows and doors, insulation and roofing to match the existing house. Electrical work will be included as well but some savings can be realized if the addition is a breezeway or sunroom without electrical outlets.

The signed contract for the room addition should list all the included work, but it is of utmost importance to know what is not included. Is there any demolition or site preparation work not included in the contractors bid? Does an old foundation need to be removed before the new one is poured? Does the new foundation site require any leveling? Are there any plumbing or HVAC considerations? Will the work require any state or county fees that the contractor will not pay as part of the contract? Failure to address any of these issues will cost you money or leave you with a half-completed addition when you run out of funds.

There is an old joke about a man who chases a beautiful woman for many years without success but finally she succumbs to his charms. His victory complete, the man then complains to his friend “Now that I have her, what will I do with her?”. With a room addition the “victory” is when the final payment is made to the contractor and the noise of power saws, hammering nails and construction worker banter all goes away. You turn to your friend and say, “Now that I have this room, what do I do with it?”. You wonder how much it will cost to complete the second step of the process.

Turning a bare room into a useful area is a bit like adding accessories to a car. Adding a GPS system, a sound system, tinted windows are all amenities that drive up the cost of a vehicle. With an added room the two most expensive amenities will be any plumbing if the added room is a kitchen or bathroom and any special electrical wiring. Your contract may call for three 110-volt electrical outlets but what about the 220-240-volt outlet needed for an electric oven? Other costly amenities are custom windows and window treatments like drapery or shades, special flooring, and items that make the room more atheistically pleasing like artwork or mirrors.

The last cost consideration will be the furniture and any electronics for the new room. If you have run low on funds, there are great deals for decent furniture at thrift shops and Habitat for Humanity stores where a decent bedroom set can be purchased for way less than buying a new set. A big screen HDTV, sound system, workout gear, easy chairs and sofas are all items where the wise shopper can find great deals.

Finally, the “first step” costs of a room addition in the Los Angeles area is about $200 to $220 per square foot and add another $50 to $100 to that figure if the added room is a bathroom or a kitchen. If the addition is to an upper story or over a garage it is best to consult with a qualified contractor as there will be added costs to comply with local building codes. The “second step” costs are largely the choice of the homeowner and the limitations of his or her budget.