Additions in Los Angeles, CA
Full-scope room additions, second-story expansions, multi-family additions, and commercial building expansions across Los Angeles. One licensed team handling design coordination, foundation and structural work, MEP, finishes, and LADBS compliance from our Pasadena headquarters.
250–550
$/sq ft typical Los Angeles finished room / home addition range (2025–2026 planning)
LADBS Permits & Zoning
Any addition of square footage, footprint change, or second story requires a building permit from LADBS plus trade permits for electrical, plumbing, and mechanical. Zoning review (ZIMAS), floor-area ratio limits under the Baseline Mansionization Ordinance, hillside and seismic considerations, and historic-resource review can apply. We coordinate plan check and clearances.
Building Stock & Structural Reality
LA includes wood-frame residences, multi-family buildings, commercial structures, and hillside properties. Ground-floor additions typically need new foundation and roofline tie-in; second-story work requires structural engineering, foundation reinforcement, and shoring. Exterior finishes must match or complement existing stucco, siding, or cladding.
One License, Multi-Trade Coordination
B-license general contracting plus C-33 painting lets us self-perform or tightly coordinate foundation, framing, roofing, MEP, exterior envelope, interior finishes, and final coatings — critical for schedule-driven residential and commercial addition projects.
Citywide & Corridor Reality
High-intent demand spans residential room and second-story additions across neighborhoods from the Valley to the Westside and Eastside, multi-family expansions, and commercial or office building additions. Occupied-property phasing, neighbor coordination, and LADBS timeline management are standard.
Our Los Angeles Addition Process
Assessment
On-site review of the existing structure, lot, zoning constraints, access, and desired program (bedroom, suite, second story, commercial expansion). We flag structural, hillside, historic, and floor-area issues early. Pasadena HQ supports efficient mobilization citywide.
Design & Engineering Coordination
Architectural and structural coordination, soils report when required, Title 24 energy compliance, and clear scope covering foundation, framing, roof, MEP, exterior matching, and interior finishes. Pricing presented as planning ranges with on-site confirmation.
Permits
We prepare and submit LADBS applications, coordinate plan check corrections, and obtain required clearances (zoning, fire, public works as applicable). Trade permits for electrical, plumbing, and mechanical are sequenced with the building permit.
Execution
Phased construction with dust, noise, and access controls so residents or tenants can remain where practical. Foundation, framing, roofing, MEP rough-in, exterior envelope, insulation, drywall, finishes, and coatings sequenced under one project manager.
Walkthrough & Close-Out
Final inspections, Certificate of Occupancy or final sign-off coordination, punch list, as-built notes, and warranty handover. For commercial expansions we align with landlord or owner schedules.
Projects staged from our Pasadena headquarters for reliable response across Los Angeles neighborhoods and commercial corridors.
Los Angeles Addition Regulatory Notes
Do I need an LADBS building permit for a room or home addition?
Yes. Any addition that adds square footage, changes the building footprint, or adds a story requires a building permit from the Los Angeles Department of Building and Safety, plus trade permits for electrical, plumbing, and mechanical work. Garage, attic, or basement conversions to living space also require permits.
Source: LADBS building permit requirements
How does zoning affect additions in Los Angeles?
Zoning (checkable via ZIMAS) and the Baseline Mansionization Ordinance limit floor-area ratio on many single-family lots (commonly 0.50 FAR with height and story caps). Hillside areas, Very High Fire Hazard Severity Zones, and historic districts add further constraints. Allowable addition size should be confirmed early in design.
Source: LA Zoning / Baseline Mansionization Ordinance & LADBS guidance
What about second-story additions and structural requirements?
Second-story additions almost always require structural engineering, foundation evaluation and often reinforcement, and careful temporary shoring. Existing first-floor occupancy can be maintained with proper phasing and protection. Engineering and soils reports are coordinated as part of the permit package.
Source: LADBS structural & existing-building practice
Do SCAQMD and Title 24 rules apply to additions?
Yes. Los Angeles is within the South Coast AQMD; architectural coatings must meet Rule 1113 VOC limits. Additions trigger Title 24 energy compliance for the new conditioned space and often affect the overall envelope and systems. We specify compliant materials and documentation.
Source: SCAQMD Rule 1113 & California Energy Code / Title 24
What Los Angeles Clients Say
4.9
36 verified reviews
“They added a master suite to our Mid-City home while we lived there. Foundation, framing, and finishes were coordinated cleanly, and the exterior matches the original house. LADBS process was handled without drama.”
Homeowner
Mid-City
“Second-story addition in the Valley. Structural work and foundation reinforcement were thorough, and we stayed on the first floor the whole time. Certificate of Occupancy came in on schedule.”
Homeowner
San Fernando Valley
“Commercial rear expansion on our East LA building. Business kept running, dust and access were controlled, and final approvals landed when promised.”
Property Manager
East Los Angeles
Commercial Additions — Also Serving Surrounding Hubs
Delivering dedicated commercial additions expertise, local code compliance, and licensed crews across Southern California.
Also serving
Looking for commercial additions outside of Los Angeles? We serve the greater Los Angeles basin, Orange County, and San Gabriel Valley.
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Room & Building Additions Los Angeles — FAQ
Planning ranges for finished additions typically run $250–$550 per square foot depending on type and complexity. Basic ground-floor room additions often $250–$325/SF; mid-range with bath or upgraded finishes $325–$400/SF; master suites and higher-spec work $375–$475/SF; second-story additions commonly $400–$550/SF due to structural and foundation work. Example totals: 200–400 sq ft room $80k–$200k; master suite $120k–$250k; second story $200k–$500k+. Final price is always based on on-site scope, engineering, finishes, and site conditions.
Yes. We hold California CSLB License #1083764 covering General Building (B) and Painting & Decorating (C-33). We are licensed, bonded, and insured for residential room and second-story additions, multi-family expansions, and commercial building additions throughout Los Angeles.
Yes. Any addition of square footage, change to the building footprint, or second-story construction requires a building permit from LADBS, along with electrical, plumbing, and mechanical trade permits as applicable. Conversions of garage, attic, or basement space to living area also require permits.
Many single-family lots are subject to floor-area ratio limits under the Baseline Mansionization Ordinance (often 0.50 FAR) plus height and story caps. Hillside, fire-hazard, and historic overlays can further restrict size and design. We check ZIMAS and zoning early so the proposed addition is feasible.
Yes. We routinely phase ground-floor and second-story additions so residents can remain on site, using temporary barriers, weather protection, dust control, and sequenced access. Second-story work requires careful shoring and protection of the occupied lower level.
Our headquarters is at 1055 E Colorado Blvd, Pasadena, CA 91106. Drive times to most LA neighborhoods range from 15–45 minutes depending on location and traffic, supporting reliable mobilization citywide.
Yes. We perform commercial and multi-family additions and expansions in addition to residential room and second-story work. Commercial projects follow LADBS commercial pathways, accessibility, and fire-life-safety requirements, with occupied-building phasing when needed.
After design and permit issuance, a straightforward ground-floor room addition often runs 3–5 months of construction; master suites 4–6 months; second-story additions longer due to structural and foundation work. Permit and plan-check timelines vary with package completeness, zoning complexity, and LADBS workload.
Ready to plan your Los Angeles addition?
Get a clear scope, realistic 2025–2026 LA pricing, and a phased plan that works with your property, zoning, and household or business operations. Licensed GC serving residential, multi-family, and commercial additions across Los Angeles from our Pasadena HQ.
Get In Touch
Phone
(626) 240-4624Service Area
Pasadena · Los Angeles · LA County
Response Time
Monday–Friday 7:00 AM – 5:00 PM
★ CSLB Licensed · Bonded & Insured · Est. 2004