ADUs
Plan an ADU in San Diego County.
Detached, attached, garage conversion and junior ADUs, planned, permitted and built by a licensed San Diego contractor.
ADU overviewADU types
Plan your ADU
Services
Three practices, one team.
ADUs, remodels and additions, and custom homes, designed and built across San Diego County.
All servicesRemodeling and additions
Custom homes
How we work
Resources
Tools and guides for planning your project.
Free calculators, permit guides and the local rules, for building in San Diego County.
All resourcesAbout
Why choose BHI Builders.
A licensed San Diego County builder of ADUs, remodels and custom homes since 1997: who we are, what clients say, and how we work.
About us
Remodeling and additions in San Diego County
We remodel kitchens, baths and whole homes, and we add rooms and second stories, starting with what your existing house can support.
BHI Builders, a California general building contractor licensed since 1997 (CSLB 738313), designs, permits and builds whole-home remodels, kitchens and baths, room additions and second stories across San Diego County, with one contract and one project manager from the first measurement to the final inspection.
Book a call and we walk the house with you before anything is drawn.
The short answer
Four things decide it: who the work is for, what we take on, what shapes the scope and the schedule, and what you bring to the first call.
Everything a remodel can include
The work a high-end remodel covers in San Diego County, grouped the way a house is lived in. Most projects touch two or three of these at once.
The plan, the light and the systems reworked together.
The room that decides how the rest of the house works.
Primary suites, guest baths and powder rooms.
More room on the lot you already own.
On the call we tell you which of these your house needs, including when the answer is less than you planned.
What you can change
Each has its own rule in the City of San Diego. The 17 other cities and the County apply their own; the finder below opens each authority's page.
Remodel, add on, or rebuild?
The right answer comes from the house and the lot, not from a rule of thumb. These are the questions we work through with you on the first walk-through.
The structure and the footprint can serve you, and the change is in how the rooms work: the plan, the kitchen, the baths, the light and the systems.
You need more room, and the lot and the zone leave space to build out on the ground or up as a second story.
So much would be worked around that the lot, not the house, is the asset. A replacement home starts from today's code.
Two San Diego rules decide more of this than taste does: the 45-year historic screening and, in the Coastal Overlay Zone, the 50 percent exterior wall rule. Both are explained further down.
Our remodels and additions
One remodel shown room by room, and the remodels and additions on our permit record, each with its type, its community, the office that issued the permit and the year.
Every row is a public permit record under license 738313 or in BHI's name. Ask us on a call about any of them.
Craft
The test of a good addition is that a visitor can't find the seam. That is decided before construction, in the drawings and the material list, not on site.
We match the roof's pitch and its tile, the plaster's texture, the window profiles, the trim and the floor. Where a material is no longer made, the closest current one is chosen and shown to you before anything is ordered. And before we build on the old house, its footings and framing are opened and checked.
How a remodel runs with BHI
The same six stages every BHI project moves through, with what you have in hand when each one ends. A remodel adds one question at discovery: what the house can carry, and what has to be opened up to find out.
Scope and schedule
No two remodels are alike, so the scope is settled with you on a call and a walk-through. These are the things that shape it.
Living at home during the work
Whether you stay home depends on how much of the house is open at once. A kitchen or a bath can usually be phased around you. A whole-home remodel usually means some time away.
Either way, it is settled on the call and in the plan, before any demolition: where dust walls go, which bathroom stays working, where materials are kept and how the site is closed up each day.
Local rules
San Diego County has 19 permit authorities. Choose yours to open its own page. The notes beside it are the City of San Diego's rules for remodels and additions.
Our tools cover all 19 permit authorities: 18 cities and the County.
In the City of San Diego a kitchen or bath remodel in a house or duplex that changes no structure, framing or exterior walls and adds no plumbing fixtures can use a No-Plan Building Permit. Roof replacements and buildings without a legal permit can't use it, and a historic review can still apply.
Any construction permit on a parcel with a structure 45 years old or older goes through the City's historical screening first (Municipal Code 143.0212). Interior work is exempt; exterior work on a remodel or addition is not. The review typically takes ten business days for a ministerial project, and a house that may be significant gets a site-specific study.
In the Coastal Overlay Zone, demolishing or removing half or more of a house's exterior walls, measured in linear feet floor by floor, needs a Coastal Development Permit, including when it happens by accident. Building onto the outside of a wall counts as removing it.
The City asks for a demolition plan with a wall matrix, every wall in linear feet and in percent removed and kept. A wall meant to stay that turns out to have dry rot or termite damage still has to stay, treated and sistered in place. Once the project passes final inspection, the finished house becomes the new set of existing walls.
In the City's RS-1-1 to RS-1-7 zones the limit is 24 feet at the setback and 30 feet overall, inside an angled building envelope plane: 45 degrees on lots under 75 feet wide, 30 degrees up to 150 feet. West of Interstate 5 as it ran on January 1, 1971, the voter-approved Coastal Height Limit caps any building or addition at 30 feet.
A residential addition that increases assessable space by more than 500 square feet pays school fees. The City measures the space; the school districts set the fee and collect it, and the receipt is uploaded when the permit is issued.
An owner can pull the permit and act as the general contractor by signing the City's Owner-Builder Verification form. The owner then carries the responsibilities a licensed contractor would, for the work and for anyone hired to do it.
The 2025 Energy Code applies to permit applications filed from January 1, 2026. Its prescriptive path calls for heat pump space heating in additions; the performance path allows alternatives that meet the same energy budget. The Energy Commission's own summary says the code mandates no specific technology.
Plan before you call
A first read of your lot, and the guides behind the rules above.
Real questions
Usually, in the City of San Diego. Painting, flooring and cabinet work alone need no building permit, though new wiring or plumbing does. A remodel that changes no structure, framing or exterior walls and adds no plumbing fixtures can use a No-Plan Building Permit, issued without plan review. Move a wall or add a fixture and the permit needs plans.
When the structure, the framing, an exterior wall or the fixture count changes. Moving a wall, enlarging a window, adding a sink or a shower, or adding any space takes a plan set: drawings to scale, the City's forms, Title 24 energy compliance and the stormwater form. A water meter data card goes in when new fixtures are added.
If it is 45 years old or older and the work shows outside. The City screens any construction permit on a parcel with a structure 45 years old or older, No-Plan permits included. Interior-only work is exempt. The screening typically takes ten business days for a ministerial project; if staff find nothing potentially significant, the parcel is cleared for five years.
Less than half of the exterior walls, without a coastal permit. In the Coastal Overlay Zone the City counts exterior walls in linear feet, floor by floor. Removing half or more needs a Coastal Development Permit, an addition built against a wall counts as removing it, and an accident still counts. The demolition plan lists every wall in feet and percent.
It depends on the yard, the structure and the zone. A ground-floor room keeps stairs out of the plan and is often simpler to engineer. A second story keeps the yard but has to fit the zone's height and angled plane, and the coastal height limit west of Interstate 5 as it ran on January 1, 1971. We look at both on the first walk-through.
An engineer answers that, before any drawing is final. The foundation, the framing and the load paths are checked first. Many houses need some strengthening, from new footings to shear walls and beams. Our permit record includes a 234 square foot second-floor room addition in San Marcos in 2022 and a second-story loft over a remodeled kitchen in Mira Mesa in 2010.
Often, with phasing. A kitchen or a bath can usually be phased around you. A whole-home remodel usually means some time away. That is settled on the call and in the plan, before any demolition.
It depends on how much of the house you keep. A remodel keeps the foundation, most of the walls and the house's permit history. Once the plan, the structure and the systems all change, a replacement home starts fresh under today's code, with the City's 45-year screening before demolition and, near the coast, the 50 percent wall rule. We walk through both with you.
That is decided in the drawings. The roofline, the tile, the plaster, the windows, the trim and the floors are matched in the plans and the material list. Where a material is no longer made, the closest current one is chosen with you before construction.
Older houses often hide something; the aim is to find it early. Old wiring, failed plumbing, undersized framing, moisture and unpermitted work are the usual finds. The permit history and an existing-conditions review come first, and any change to the work is talked through with you before it is done.
Yes, as an addition to the house. The garage becomes rooms of the house, permitted as an addition. Because a garage isn't assessable space, the converted area counts toward the 500 square feet that bring school fees. A separate unit with its own kitchen is an ADU, with its own rules.
Not always. Under the 2025 Energy Code, in force for applications from January 1, 2026, the prescriptive path calls for heat pump space heating in an addition. Extending the house's existing system is allowed, and the performance path accepts other designs that meet the same energy budget.
Months, with the permit as the variable. Design and engineering come first, then plan check with the City, which publishes a weekly snapshot of its queues and asks for complete submittals. A historic screening or a coastal review adds its own cycle. Your own timeline is set with you once the project starts.
Over 500 square feet, yes. A residential addition that increases assessable space by more than 500 square feet pays school fees in the City of San Diego. Garages, patios and detached accessory structures don't count as assessable space. The school districts set the amount and collect it.
Yes, as an owner-builder. The City accepts an owner-builder permit with its verification form. You then carry a contractor's responsibilities for the work and for anyone you hire. If you hire a contractor instead, check the license with CSLB: ours is 738313.
Book a call
Book 30 minutes with Koosha Tabrizi to talk through your house and what you want to change.
BHI Builders (B H I Builders Inc.), California contractor license B #738313.
