Home Addition Contractor in Murrieta, CA
A home addition extends your existing house to add a bedroom, a primary suite, an office, or a larger living area. Unlike an ADU, an addition becomes part of your home rather than a separate dwelling, so it has no kitchen and no separate entrance.
Spencer has worked in construction since 1990 and has built more than 100 room and home additions across the Temecula Valley. License B-842038. Call (951) 551-6165.
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Home Additions We Build in Murrieta
Murrieta's 1990s and 2000s housing stock is at the age where families outgrow the original floor plan. These are the projects that solve it.
Bedroom additions
The most common request in Murrieta. A new bedroom needs egress, meaning a window sized to allow escape, plus a closet to count as a bedroom for appraisal purposes. Both are easy to get right during framing and expensive to retrofit.
Primary suite additions
A bedroom plus a bathroom, often with a walk-in closet. This combines structural work with the bathroom work we do every week, so it sits squarely in what we build.
Living space expansions
Extending a family room, a dining area, or a kitchen footprint outward. Removing an existing exterior wall means engineering, because that wall is usually carrying load.
Home office additions
A dedicated room with its own door, proper electrical for equipment, and enough insulation to keep calls quiet. Demand for these has not gone back down.
In-law suites
A bedroom and bathroom connected to the house for a parent or adult child who needs proximity rather than independence. If it gains a kitchen and a separate entrance, it becomes a legal ADU with different rules — we walk through which one you actually want on the first visit.
Loft additions and attic conversions
Where the lot leaves no room to build outward, building up adds square footage without touching your setbacks. See our loft additions and attic conversions page.
Where Additions Work in Murrieta
The same addition question gets a different answer depending on which side of the freeway you live on.
West-side parcels have room
Butterfield, California Oaks, and the semi-rural lots off Los Alamos Road often have the side and rear yard to build outward under standard setbacks. These are the lots where a ground-floor addition beats every other option.
East-side tracts are tighter
Central Park, Greer Ranch, and the newer 92563 tracts were platted dense. Where standard setbacks leave no buildable footprint, a loft addition or a garage conversion usually makes more sense than building outward.
HOA review is the norm
California Oaks, Copper Canyon, Greer Ranch, Central Park, and the gated communities all carry architectural standards. An addition is visible from the street, so exterior matching is not cosmetic — it is what gets the project approved. We design to pass the first time.
Additions follow standard setbacks
State law grants ADUs a four foot side and rear setback. A room addition gets no such exemption and follows Murrieta's standard residential setbacks, which are larger. Some lots that can hold an ADU cannot hold an addition. We measure before design.
What a Home Addition Involves
More structural work than most homeowners expect, which is why it costs what it does.
Foundation
New square footage needs a new foundation, tied properly to the existing one. On a slope this means engineering and possibly retaining. This is not the part to save money on.
The roof tie-in
Where the new roof meets the old one is where additions leak. The tie-in has to be detailed on the plans and built correctly, because a leak at that junction is the most disruptive repair on the building.
Removing an exterior wall
To open the addition into your house, an exterior wall comes out. That wall is usually load bearing, so a beam and posts replace it, sized by an engineer and inspected.
Electrical, HVAC, and insulation
New square footage adds load to your panel and your HVAC. An addition tied into an already maxed system leaves you with a room that never heats or cools properly. We check both before quoting.
Matching the exterior
Stucco texture, roof tile, window style, and color all have to match or deliberately complement. Most Murrieta housing went up between 1990 and 2006, which makes matching more achievable than in an older, more varied neighborhood.
What a Home Addition Costs in Murrieta
A 500 square foot home addition runs $175,000. That total covers construction, plans, engineering, and typical site prep.
For reference, our detached ADU builds run $225,000 at 499 square feet and $290,000 at 749 square feet, covering construction, plans, engineering, typical utilities, and standard finishes.
Estimated costs. Every property is different, so your final price depends on your lot, design, and finish selections. We give you a firm number after a free site visit.
What moves the price
Foundation work and whether your lot has slope. Whether the roof tie-in is simple or complex. Panel and HVAC capacity. Whether the addition includes a bathroom, which brings plumbing into the scope. Finish level.
What sits outside a construction number
Site plan, city permit fees, school fees, and structural engineering. Depending on your property, a soils report, grading, retaining walls, and HOA fees.
Murrieta Permits and HOA Review
A home addition in Murrieta needs a building permit, structural plans, and inspections at each stage. Murrieta incorporated in 1991 and runs its own Building and Safety Division. We handle the submittal and every plan check correction.
Where an HOA or a gated community association applies, that review comes first. Bear Creek runs guarded gates and its own architectural review, and California Oaks, Copper Canyon, Greer Ranch, and Central Park all carry design standards. We submit to the association, then the city.
Setbacks matter more for an addition than for an ADU. State ADU law grants a four foot side and rear setback that overrides local zoning. A home addition gets no such exemption, so we measure and confirm your buildable area before design.
How Long It Takes
You keep living in the house throughout. We seal the opening between the addition and your home until the new structure is weathertight.
Two to four months, including structural engineering and HOA review where one applies.
Three to six months depending on size, foundation work, and roof complexity.
Roughly five to ten months from first call to final inspection.
Our Process
Free site visit
We measure your lot, confirm your setbacks, check the foundation, panel, and HVAC capacity, and look at how the roof will tie in.
Design and engineering
Plans drawn and structurally engineered, with your selections approved.
HOA review, then city permits
Association review where one applies, then City of Murrieta permits, with every correction handled by us.
Foundation and framing
With inspections at each stage.
Rough trades
Rough plumbing, electrical, and HVAC, then insulation and drywall.
Exterior matching and finish
Exterior matching, finish work, and paint.
Final inspection
Final inspection and walkthrough.
Not Sure an Addition Is the Right Build?
If the goal is space for your own household, build the addition. If the goal is rental income or a fully independent living space, an ADU is the better tool — it carries a lighter setback requirement and returns rent every month. Trying to do both with one structure usually produces something that serves neither well.
See our ADU services or our full Murrieta services page to compare. We walk through the tradeoffs on the first visit.
Licensing and Credentials
More than 350 completed projects, including more than 100 room and home additions.
California general contractor license
B-842038, active and in good standing.
Experience
Spencer has worked in construction since 1990 and has built in the Temecula Valley since 2004. More than 350 completed projects.
Bonded and insured
General liability and workers compensation certificates provided before work starts.
Licensed subcontractors only
Every subcontractor on your job is licensed and insured.
Verify any California contractor license, including ours, through the Contractors State License Board. Check it before you hire anyone.
What Temecula Valley homeowners say
More than 350 completed projects in Southern California and the Temecula Valley, and a five star rating across Google, Yelp and Houzz.
“Spencer did an amazing job. He converted our loft into a bedroom with a walk in closet. He was flexible and very communicative throughout the whole process. He kept it as clean as possible and cleaned up everyday before leaving. We are extremely happy with his work.”
“We have done several projects with Spencer Woollard through the years including a major two-story addition on our Temecula home. He is a highly-skilled contractor and great to work with. He keeps a clean job site, communicates regularly, and has immaculate workmanship. Spencer is the best in town.”
“The bid was competitive and very reasonable. Spencer was responsive and accommodating; always ready to answer any questions that came up or think outside the box to keep us on budget. His subcontractors were professional and efficiently organized. The whole process was extremely quick once the permits were in place... just under four months from start to finish.”
A 500 square foot addition runs $175,000, covering construction, plans, engineering, and typical site prep. Cost turns on foundation work, roof tie-in complexity, whether a bathroom is included, and your finish level. We give you a written scope after walking the property rather than a number over the phone.
An addition becomes part of your house, with no kitchen and no separate entrance. An ADU is a legal second dwelling with its own kitchen, bathroom, and entrance. The ADU carries different rules, a lighter setback requirement, and rental potential.
Yes. A building permit from Murrieta's Building and Safety Division, structural plans, and inspections at each stage. Where an HOA applies, its architectural review comes first. We handle the submittal and every plan check correction.
An HOA cannot block an ADU, but it can and does review an addition, because an addition is far more visible from the street. Exterior materials, colors, and roofing go through architectural review. We design to the community standard so the package clears on the first pass.
Yes. We seal the opening between the addition and your home until the new structure is weathertight, so the disruption stays outside your living space for most of the build.
If it has a kitchen and a separate entrance, it is legally an ADU. If it is a bedroom and bathroom connected to your house, it is an addition. The right answer depends on whether the person needs independence or proximity.
Get a free Murrieta site visit
We measure your lot, check your setbacks and your panel, and tell you what your property will support. Call (951) 551-6165 or request a consultation online.
Request a site visit
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