Home Addition Contractor
Home Additions in Los Angeles
Need more space but love where you live? We build additions that feel like they were always part of the house.
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Moving in Los Angeles is expensive. Property taxes reset, transaction costs add up, and you leave a neighborhood you know. For many families, building an addition is a smarter path — more space, more value, same street.
ARM Builders has been building additions across West and Central LA for over 20 years. We handle everything from the initial design coordination through permits, construction, and final inspection — and we build additions that integrate seamlessly with your existing home rather than looking like they were bolted on later.
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TYPES OF ADDITIONS WE BUILD
What We Build
- Second-story additions — add a full floor above your existing footprint
- Primary suite additions — bedroom, bathroom, walk-in closet, and privacy
- Room additions — extra bedrooms, home offices, playrooms, family rooms
- Guest houses and pool houses — separate structures on the same lot
- Garage additions and conversions
- Kitchen and dining expansions — open up the back of the house
- Laundry rooms and mudrooms — practical additions that change how the house functions
- Additional storage — built-in solutions that free up living space
HOW IT WORKS
How a Home Addition Works
Additions are structurally more complex than remodels. You're tying new framing into an existing structure, which means foundation considerations, load calculations, and careful engineering — not just construction. This is exactly where having a civil engineer running your project makes a difference.
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WHY ARM FOR YOUR ADDITION
Why Homeowners Choose ARM for Home Additions
- Structural expertise built in. Additions require load calculations and structural review. Aaron Weiss is a civil engineer — that expertise is part of every project, not an add-on.
- Permits handled completely. Additions without proper permits are a liability when you sell or refinance. We pull every permit correctly and manage the full approval process.
- Seamless integration. We match your existing structure — framing, roofline, exterior finishes — so the addition looks like it was always there.
- One contractor, every trade. Framing, electrical, plumbing, HVAC, drywall, finishes — all coordinated by ARM under one contract.
- Licensed and insured. CSLB Lic. #915352, Class B. Your home and investment are protected.
Home Additions in LA Frequently Asked Questions
How much does a home addition cost in Los Angeles?
Most home additions in LA run between $300 and $500 per square foot, depending on complexity, structural requirements, and finish level. A second-story addition over the full footprint of a house will cost significantly more than a single-room ground-floor addition. We provide detailed estimates based on your specific project.
Do I need permits for a home addition in Los Angeles?
Yes, always. Any addition that adds square footage, changes the roofline, or involves structural work requires permits from the city or county. Unpermitted additions can be flagged during a sale, required to be demolished, or create liability if something goes wrong. ARM handles all of it.
How long does a home addition take?
A straightforward room addition might take 3 to 5 months. A second-story addition over an existing structure typically runs 6 to 10 months, including the permitting phase. We give you a realistic timeline at the start — not a best-case number that slips.
Can I stay in my home during the addition?
In most cases, yes — especially for additions that don’t require significant work inside the existing living space. We discuss sequencing during the consultation and do what we can to minimize disruption to your household.
What's the difference between an addition and an ADU?
A home addition is an expansion of your primary residence — it becomes part of the main house. An ADU (accessory dwelling unit) is a separate living unit on the same lot that can be rented or used independently. If you’re looking to add a rentable unit or a fully self-contained guest space, the ADU page covers that. (link to ADU page)
Will the addition match the rest of my house?
That’s something we focus on specifically. We match exterior materials, rooflines, and architectural details so the addition integrates with the existing structure rather than looking like it was added as an afterthought.
Ready to Add to Your Home?
If you've outgrown your space but aren't ready to move, let's talk. We'll walk your property, understand what you need, and give you an honest picture of what's possible.
Request Your Free ConsultationARM Builders, Inc. · CSLB Lic. #915352 · 877.755.1350 · armbuildersinc.com