Home Additions · Los Angeles

More house, without moving.

LA real estate isn’t getting cheaper. The smart move for many of our clients is to add square footage to the home they already own , a second story, a primary suite, a kids’ wing, a home office addition.

We design it, we permit it with LADBS, we build it. Fixed price.

See your addition rendered → • Get a fixed-price estimate →

CSLB #[CSLB Number , pending owner verification] · Bonded · Insured · LADBS-permitted · Hillside ordinance experience · Fixed-price

What an LA addition actually costs in 2026

Type	Typical sqft	Typical investment
Single room addition (bedroom, office, sunroom)	200 to 400 sqft	$80,000 to $180,000
Primary suite addition (bedroom + bath + walk-in)	400 to 700 sqft	$200,000 to $400,000
Second-story addition (full or partial)	800 to 1,800 sqft	$400,000 to $900,000
Hillside addition (cantilever, complex foundation)	varies	+20 to 40% above flat-lot equivalent

LA additions cost more than the national average , California energy code, seismic engineering, LADBS permit fees, and licensed-trade labor all add up. Hillside, historic, or coastal lots add further.

Ten months of careful work. Same roof line, twice the home.

Types of additions we build

Second-story additions

The classic LA play: 50s/60s ranch on a flat Valley lot, single story, 2,200 sqft. Add 1,200 sqft on top. Bedrooms move upstairs, the existing footprint becomes living + primary suite. Plan for 8 to 14 months from contract to keys.

Primary suite additions

Often built to the rear of the existing footprint. 500 sqft adds bedroom + bath + walk-in closet, sometimes a small office. Lets you keep the existing primary as a guest suite or kids’ room.

Hillside additions

Bel Air, Hollywood Hills, Mt. Washington, Pacific Palisades. Cantilever construction, deep caissons, fire-access requirements. We’ve built all of it. Permit timelines run longer (12 to 20 weeks plan check) and engineering is more complex , but the value-add for a hillside home is enormous.

Detached studio / office / gym additions

Smaller-footprint outbuildings on the same lot. Often confused with ADU but not the same , an addition shares mailing address and utility metering with the main house and isn’t a separate unit. Cheaper and faster than a full ADU.

Sunroom / glass-enclosed patio additions

Folding-glass-wall systems that turn covered patios into thermally controlled four-season rooms. Permitted as conditioned space. ~$80 to 180K for a 250 to 400 sqft sunroom.

What “Built for LA” means for additions

Setbacks. Front, side, and rear setbacks vary by zone. We check zoning before any design work , sometimes a lot’s effective buildable area is much smaller than expected once setbacks, slope, and easements are applied.

Floor Area Ratio (FAR). LA’s FAR limits the total square footage you can build on a given lot. Adding a second story is usually fine; adding a 2,000 sqft addition to a small lot may not be. We tell you upfront.

Hillside Ordinance. Hillside lots have additional rules: maximum cubic capacity, ridge protection, fire access, ember-resistant cladding, drainage. We’ve navigated all of it.

HPOZ (Historic Preservation Overlay Zone). Hancock Park, West Adams, Greater Wilshire, Highland Park, Pasadena districts. Additions in HPOZ require Cultural Heritage Commission review , we know the path.

Coastal Commission. Palisades, Venice, parts of Malibu in coastal zone. Additions over a certain size or height trigger Coastal Development Permit. Adds 4 to 8 weeks.

Title 24 and energy code. Every conditioned addition must meet current Title 24 , insulation, glazing, HVAC efficiency, HERS testing on new HVAC.

Drawn properly. Engineered properly. Permitted properly.

What’s in a fixed-price ACE addition contract

Architectural design (every elevation, every interior plan)
Structural engineering (especially critical for second-story over existing)
Title 24 / energy compliance
LADBS permits + plan check management
Foundation work (often the biggest variable in cost)
Framing, roofing, MEP, drywall, finishes
Integration to existing home (matching siding, roof, interior trim language)
HVAC capacity upgrade if needed
Electrical panel upgrade if needed
Final inspection + Certificate of Occupancy
One-year workmanship warranty + two-year mechanical

FAQ

Will my addition look “added on”?

Not if we do our job. The biggest tell of a bad addition is when the new wing doesn’t speak the same architectural language as the original , different roof pitch, different cladding, different window scale. We design for integration, not contrast.

How long does a second-story addition take?

Plan for 12 to 18 months total. Design + permits: 4 to 7 months (longer for hillside or HPOZ). Construction: 8 to 12 months. You’ll likely need to relocate during the build phase since the roof comes off.

Can I live in the house during a single-room addition?

Often yes for a rear primary suite addition or a single-room addition that doesn’t disturb the existing house. We isolate the work area with proper dust barriers and protect existing finishes. Some demo days will be loud , we coordinate around your schedule.

Will my homeowners insurance change?

Yes , the policy needs updating before construction starts (course-of-construction rider) and again at completion (replacement value adjustment). We’ll prompt you with the right timing.

Does an addition require a panel upgrade?

Often. Many older LA homes have 100A or 125A service which can’t carry an addition’s load (especially with HVAC and modern appliances). We test during design and itemize a panel upgrade in the contract if needed.

Can I add a second story to a hillside home?

Often yes. Hillside ordinance has specific rules about ridge height, mass, and setback. Sometimes the buildable envelope is constrained , we’ll evaluate during feasibility.

What’s the value-add of an addition versus a remodel?

Square footage added in LA usually appraises at $400 to $1,200/sqft depending on neighborhood. A $300K addition that adds 600 sqft in a $900/sqft neighborhood appraises at ~$540K , net value gain of $240K plus the cost-recovery of finishes. The math usually works in LA.

Can I do an addition + ADU together?

Yes, and it’s often cost-efficient (one mobilization, one permit cycle, one disruption). Plan for 14 to 20 months and a substantial single contract.