- (669) 609-0069
- truebuildersca@gmail.com
- Lic # 1110631
Home additions in San Jose, built to look original.
In-house design, engineering, City of San José permits and construction under one contract, with a fixed price before work begins.
- 25+ yearsof building experience
- CSLB #1110631licensed and insured
- One contractdesign, permits and build
- 1-year warrantyon all workmanship
The True Builders difference
The space you need, on the lot you own. Your fixed price is set before we break ground.
3-9months of construction
1single point of contact
25+years of experience
In short: Most San Jose home additions take 3-9 months of construction after design and permits. Every addition needs City of San José permits; second stories can also need planning review.
BeforeAfterDesign concept
Same home. One seamless new room.
Roofline
The roof extends with a clerestory bump-out, so the addition reads as one house.
Exterior
Stucco, trim and window frames are matched so the new room looks original.
Glass
A narrow slider becomes a wall of glass that opens onto a new garden patio.
Illustrative design concept. Ask us about completed additions near you.
Why True Builders
Add the space you need without leaving your street.
San Jose families often outgrow their homes before they outgrow their neighborhoods. The single-story ranch homes common in Cambrian, Blossom Valley, West San Jose and Willow Glen suit rear and side additions well. We engineer the foundation for local soils and tie into the existing roof, so the addition looks original.
- Roofline and exterior matched to yours
- Foundations engineered for local soils
- Electrical, plumbing and HVAC extended
- Floors and trim that flow right through
Addition options
Four ways to add space to a San Jose home.
Primary suite
A bedroom, ensuite bath and walk-in closet, set at the quiet back of the house.
Ask about this
Great room
A larger family room that opens the kitchen to the backyard behind a wall of glass.
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Second story
When the lot is tight, build up, with structural and foundation review done first.
Ask about this
Home office
A 200-300 sq ft bump-out for an office, nursery or guest room, and quick to build.
Ask about thisWhat’s included
Everything your addition needs, under one contract.
01
Design that matches
Floor plans and elevations that extend your home’s architecture, inside and out.
02
Structural engineering
Foundations, framing, beams and roof tie-ins engineered for your home and its soils.
03
Permits & planning
Zoning checks, permit drawings and any planning review handled with the City of San José.
04
Systems extensions
Electrical, plumbing and HVAC extended, and upgraded where your existing systems need it.
05
Energy efficiency
Insulation and dual-pane windows keep the new room comfortable year-round.
06
Seamless finishes
Matching floors, trim, paint and fixtures, so the addition feels like it was always there.
How it works
Five clear steps, one accountable team.
01
Feasibility visit
Week 1We measure your home, review setbacks, height limits and lot coverage, and look closely at the roof and foundation.
02
Design & engineering
Design phaseFloor plans and elevations that match your home, with structural engineering, foundation design and energy calculations.
03
Fixed price
Before constructionWith design and selections complete, you receive a fixed construction price and a schedule, with no surprise line items later.
04
Permits
City reviewWe submit the drawings to the City of San José, answer plan-check comments, handle any planning review and order materials.
05
Build & tie-in
3-9 monthsFoundation, framing, roofing and systems, then the tie-in to your home and matching finishes, inspected at every stage.
60-second planner
What kind of addition fits your home?
Your answers carry into the estimate form
Local know-how
Adding on to a home in San Jose.
Neighborhoods
Cambrian
1950s-1960s ranch homesWide single-story homes with deep backyards make Cambrian a natural fit for rear primary suites and great-room additions that keep the whole house on one level.
Willow Glen
1920s-1950s homesAdditions here have to blend into older architecture, so matching trim profiles, window styles and rooflines matters as much as getting the floor plan right.
Blossom Valley
1960s-1970s family homesGenerous lots allow ground-floor additions without giving up the backyard, most often a new primary suite or a family room built off the back of the house.
Almaden Valley
1970s-1990s homes, larger lotsBigger footprints and lots support larger family rooms and suites. Foothill properties may need a geotechnical review before the foundation is designed.
West San Jose
1950s-1970s ranch homesA popular area for primary suite additions that turn a three-bedroom ranch into a home that fits a growing family, without leaving a street you love.
Rose Garden
1920s-1940s period homesPeriod homes where every addition is designed to respect the original proportions, trim and windows that make these houses so well loved in the first place.
Setbacks & floor area
San Jose’s single-family zoning limits setbacks, height and floor area on every lot. We map your buildable area before design.
Second-story review
Larger or second-story additions can trigger planning review, especially in conservation areas such as Naglee Park.
Soils & foundations
Expansive clay soils are common in parts of the Santa Clara Valley, so every foundation is engineered for site conditions.
Protected trees
Ordinance-size trees, 38 inches or more around at 4½ feet above grade, need a permit to remove, so we design around them.
Client stories
What homeowners say about True Builders.
I am a designer in my profession and I am very much into the details… True Builders never stopped the work and continue with everything that is needed to make a progress.
Having Nathan as our project manager was an absolute blessing!… Nathan made communication a breeze, keeping us in the loop with progress updates throughout the entire project.
We collaborated with True Builders to renovate two bathrooms in our home… What stood out was their offer to select finished materials for us, saving time and energy for a fixed fee.
FAQs
San Jose home additions, questions answered.
Single-room additions of about 200-300 sq ft typically take 3-4 months of construction. Primary suite additions of 300-500 sq ft take about 4-6 months, and larger additions of 500 sq ft or more about 6-9 months. Design and City of San José permitting come first.
Yes. Additions require building permits from the City of San José, including structural, electrical, plumbing and mechanical review. Larger or second-story additions may also need planning review. We prepare and manage the full process.
On many San José lots, building out with a rear or side addition is simpler and keeps the home single-story. Building up preserves yard space when the lot is tight, but it requires structural and foundation evaluation and can involve planning review. We study both at the feasibility visit.
Yes. Matching rooflines, stucco or siding, windows and interior finishes is central to how we design additions, so the new space looks like it was always part of the house.
Often, yes, for ground-floor additions, because most work happens outside the house until the final tie-in. Second-story additions involve roof and structural work and may require temporary relocation for part of the project.
An addition expands your existing home, such as a bigger family room or a new primary suite. An ADU is a separate, independent living unit with its own kitchen and entrance, attached or detached. If you want rental income or independent space for family, an ADU may fit better.
Size, whether you build out or up, foundation and soil conditions, roof tie-ins, structural needs and how much of your existing electrical, plumbing and HVAC must be upgraded all affect cost, along with finish level. We provide a fixed construction price after design.
Adding livable square footage, especially a bedroom, bathroom or primary suite, is one of the most effective ways to build equity in the high-demand San José market. We design additions that fit your neighborhood, so they appeal to future buyers too.
Free estimate
Start with a free feasibility visit.
Tell us what kind of space you need and we’ll reach out to schedule a visit. No pressure and no obligation, just a clear plan.
- Share your projectA few details now; photos help if you have them.
- Free site visitWe measure, check feasibility and talk through ideas.
- Design and fixed priceA clear plan and a fixed price before any work begins.
More in San JoseHome remodeling · Kitchen remodeling · Garage conversions · ADUs
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