Design inspirationSecond-Story & Two-Story Addition Builders
Double your square footage without giving up an inch of yard — a full second floor built above your existing home.
Second-Story Addition across Greater Los Angeles.
A second-story addition, which turns a single-story house into a two-story home, is the highest-value move on a Southern California lot. Land is scarce, backyards matter, and building up preserves both. Done well, a second story reads as if the house was always two stories — matched rooflines, integrated stairs, and no visible seam.
The hard part isn't the new floor. It's the existing house underneath. HomeAdd's structural team reinforces the first-floor walls, upgrades the foundation where needed, and engineers the lateral system to modern seismic code before a single stick of new framing goes up.
We build second stories throughout the San Fernando Valley — Woodland Hills, Tarzana, Encino, Sherman Oaks, Studio City — and across the Westside and Conejo Valley.
Common second-story addition options.
Full second story
New floor covering most of the existing footprint — 3 bedrooms, 2 baths, laundry, and a bonus space.
Partial second story
A primary suite plus one bedroom over part of the house — keeps original rooflines and lowers cost.
Primary-suite loft
A single luxury primary suite with vaulted ceilings and private balcony, built over the living area.
Second floor + first-floor remodel
New upstairs bedrooms free up the downstairs for a bigger kitchen, family room, and office.
Detached second-story ADU
Above-garage second-story ADU that pairs beautifully with a main-house pop-up.
Roof-deck integration
Where zoning allows, we integrate a rooftop deck with proper waterproofing and railing engineering.
What's included in every HomeAdd project.
Every phase, in order.
- 1Feasibility + structural review
Inspect the existing foundation, framing, and roof. Confirm lot, zoning, and height limits.
- 2Schematic design
Floor plans, stair location, elevations, and 3D renderings.
- 3Construction documents
Structural engineering, Title 24, MEP, and permit set.
- 4Plan check & permits
Local plan-check submittal, corrections, and permit issuance.
- 5Site prep & first-floor retrofit
Foundation upgrades, new shear walls, holdowns, and temporary weather protection.
- 6Framing & dry-in
Floor system, walls, roof, windows, and exterior weather barrier.
- 7MEP & insulation
Electrical, plumbing, HVAC rough, followed by insulation and drywall.
- 8Finishes upstairs + downstairs patching
Bedrooms, baths, laundry, stair finish, and blending into existing spaces.
- 9Final inspection & handoff
Building final, punch list, walkthrough, and closeout package.
Planning ranges (Los Angeles & Ventura)
Preliminary planning ranges vary by jurisdiction, site conditions, design, utilities, and finish level. A written proposal follows feasibility and design.
Primary suite plus one bedroom, straightforward roofline, mid-range finishes.
3 bed / 2 bath second floor plus stair and downstairs patching.
Full new upstairs plus opened first floor, new kitchen, and refreshed exterior.
Filed, corrected, inspected — by us.
We prepare and submit the permit package to the department that reviews your address, whether that is LADBS, LA County, Ventura County, or a city building department in Los Angeles or Ventura County. You never touch a portal, sit on hold, or drive to a counter.
- Building permit (second-story addition)
- Structural engineering + retrofit plan check
- Title 24 energy compliance
- Mechanical, Electrical, Plumbing permits
- Panel & service upgrade coordination
- Fire sprinkler compliance (per LAMC 57)
- Hillside or HPOZ review (as applicable)
- Final building inspection & CofO
What this scope typically looks like.
Representative planning images of the kind of build described above.
Questions homeowners ask first.
Still have questions? Call (877) 544-1543 or request a callback — a HomeAdd project advisor will walk your address on Google Earth with you on the phone.
Can every house support a second story?+
No. Some homes need foundation or structural upgrades before a second story; an engineer confirms this during feasibility. Where it doesn't make sense, a rear or side addition may be the better move.
Do I have to move out?+
Often, for at least part of construction. How long depends on the design, structure and scope; we plan this with you and include it in the schedule in the proposal.
Does a second story trigger seismic retrofit of the first floor?+
Often. Adding a second story adds weight, so the building department typically reviews the lateral (seismic) design of the existing structure, and upgrades below may be required. The engineer confirms the scope during design.
How long does the whole project take?+
Timing depends on design, plan check, the existing structure and scope. We give you a realistic schedule in the proposal.
Will the second story look like it belongs?+
Yes — that's the whole design brief. We match roof pitch, eaves, window proportions, and stucco texture. The goal is an addition that looks like it was always part of the house.
Are fire sprinklers required?+
Sprinkler requirements depend on project scope and local jurisdiction rules. HomeAdd confirms applicable requirements during design and plan review and coordinates qualified trade professionals to install anything required.
Other ways to grow your home.
A kitchen addition bumps out the back of the house, takes down the wall, and makes the kitchen the heart of the home.
A private new primary bedroom, walk-in closet, and spa bath — added to your existing home.
Bigger living space with vaulted ceilings, a fireplace, and doors that open to the yard.
A fully permitted, insulated, four-season room with glass walls and matched roofline.
A brand new full or half bath added to your home — designed and permitted end-to-end.
A quiet, permitted, HVAC-served office with its own entry and built-in millwork.
Ready to plan your second-story addition?
We'll walk your property, pull the zoning, and give you a real budget and timeline — before you spend a dollar on design.