Room Additions in San Diego

Murray Lampert Design, Build, Remodel is your go-to expert for home additions in San Diego, whether it’s for a new entertainment hub like a family room or great room, an extra bedroom, a luxurious master suite, or a dedicated home office. As a fully licensed General Contractor (CA License #458038) we are committed to designing and constructing your home addition in a way that aligns perfectly with both your vision and financial plan. Room additions consistently rank among the highest-value investments a San Diego homeowner can make.

Room addition costs in San Diego vary based on the type of space, structural conditions of the existing home, finish level, and whether the addition includes a bathroom or kitchen. The ranges below reflect fully permitted, design-built projects, not stripped-down bids that grow through change orders once work is underway.

Family room or additional bedroom (no bathroom): $150,000 – $250,000 A single-room addition without plumbing (family room, home office, bedroom, or playroom) built off the back or side of the existing structure. Requires structural integration with the existing roofline and foundation, electrical work, insulation, drywall, and finish materials.

Master suite addition (with bathroom): $200,000 – $400,000 Includes a bedroom, walk-in closet, and full custom bathroom. Plumbing extension, tile work, custom cabinetry, and finish-level selections drive cost in this range. The bathroom component alone typically adds $60,000 to $120,000 to the base addition cost.

In-law suite or attached guest unit: $200,000 – $400,000 A self-contained living space (bedroom, bathroom, kitchenette, and separate entrance) that provides private accommodations for a family member. Involves plumbing, electrical, and HVAC extension, plus coordination with local zoning for setback and occupancy requirements.

Full second story addition: $300,000 – $700,000+ The most complex addition type. Requires structural engineering review of the existing foundation and first-floor framing, a complete roofing replacement, and coordination of all mechanical systems across two floors. Delivers the most square footage without reducing the footprint of your outdoor spaces.

What drives cost up: Including a bathroom or kitchenette (plumbing relocation and rough-in), HVAC extension into the new space, foundation work or soil conditions requiring engineered solutions, complex roofline integration, high-end finish selections, and permit complexity in coastal or hillside zones.

What drives cost down: A single room without plumbing, simple roofline connection, standard finish selections, and straightforward permit conditions on a flat lot.

We provide a written investment range after the first site visit, before any design work begins. Schedule a consultation to get yours.

Our design-build process keeps every phase of your home addition under one roof, from the first conversation to the final walkthrough.

1. Consultation. We start by listening. We want to understand how you use your home today, what space you are missing, and what your goals are for the addition. This initial conversation is complimentary and obligation-free.

2. Design development. Our in-house architectural designers and interior designers translate your vision into detailed drawings, renderings, and material selections. You will see exactly what you are getting, including how the addition integrates with your existing home, before a single nail is pulled.

3. Structural engineering. Every home addition requires a licensed structural engineer to evaluate the existing foundation and framing and specify how the new addition connects. Murray Lampert coordinates engineering as part of our design process, not as a separate step you manage on your own.

4. Fixed pricing. Once design and engineering are complete, we provide a written fixed-price contract. No cost-plus estimates, no vague allowances. The price is the price.

5. Permitting. We handle all permit applications and submissions to the City of San Diego Development Services Department. Our team manages the back-and-forth with the city, including plan check responses and revision cycles, so you do not have to.

6. Construction. Your dedicated Project Manager oversees every phase: demolition, foundation work, framing, roofing, rough plumbing and electrical, insulation, drywall, finish work, and final punch. Your Project Manager keeps you informed throughout. All inspections are scheduled and managed by our team.

7. Final walkthrough. Before we consider the project complete, we walk through every detail with you. The project is done when you say it is done.

Murray Lampert has been building room additions across San Diego County since 1975. We work throughout the region, including La Jolla, Del Mar, Rancho Santa Fe, Encinitas, Carlsbad, Mission Hills, Hillcrest, North Park, University City, Scripps Ranch, Poway, Carmel Valley, Point Loma, Coronado, Chula Vista, El Cajon, and surrounding communities.

Our familiarity with local building departments, San Diego zoning regulations, HOA requirements, and neighborhood-specific permitting timelines means your project moves efficiently from design through construction. Whether your home is a mid-century modern in Mission Hills, a craftsman in North Park, or a newer build in Carmel Valley, our team has worked in neighborhoods like yours.

Room additions are complex, high-stakes projects. The contractor you choose determines whether the finished space feels like it was always part of the house. Murray Lampert Murray Lampert’s in-house architectural designers ensure every addition is designed to integrate with your home’s existing architecture, not just bolted on. Our A+ BBB rating maintained since 1976 and recognition by the National Association of the Remodeling Industry (NARI) reflect the trust San Diego homeowners have placed in us for over five decades. Our no-change-order policy and price-certainty guarantee mean the number we quote is the number you pay.