How much does an ADU cost in Los Angeles?

A 400 to 500 square foot detached unit lands around $150,000 to $200,000. At 600 to 800 square feet it is roughly $200,000 to $250,000. At 800 to 1,000 square feet, $250,000 to $300,000. A 1,000 to 1,200 square foot unit runs $300,000 to $350,000, and a two-story unit $350,000 to $400,000.

Drawings and engineering for an ADU typically run $8,000 to $12,000 on their own, and most quotes you see online leave them out, which is why real projects feel more expensive than the number you read.

Hooking up to the sewer, and upsizing the main line if it cannot take another unit. Upgrading the electrical panel, and adding a separate meter if you want the tenant on their own bill. Trenching across the yard. Taking down whatever is there now. Sometimes the city also asks you to upgrade things in the main house, like smoke detectors or an earthquake gas shutoff valve.

Together those can add $10,000 to $60,000. We walk the site specifically looking for them before we give you a number.

The slab, the walls and the roof already exist. The money goes into a new or resurfaced slab with a moisture barrier, insulation, windows, a bathroom, a kitchen, wiring, plumbing, heating and air, and fire separation if it touches the house. A detached unit pays for the foundation, framing and roof on top of all of that.

In most central and westside neighborhoods, a one-bedroom ADU rents for enough to cover the construction loan with room left over, and the unit adds appraised value to the property. We will run those numbers with you before you spend anything on drawings.