Adding square footage to a San Marino home is a structural project with full design, engineering, plan check, and inspection cycles. This guide covers what to expect from feasibility through final inspection.
Feasibility comes first
Before any design work, a feasibility walk tells you what is buildable. Setbacks, lot coverage, height limits, hillside ordinance applicability, and foundation conditions all narrow the addition envelope. Some San Marino lots can support a 1,000 sf rear addition. Some can only support a 200 sf bump out. Hillside parcels may need foundation retrofit on the existing house before the addition is even framed. Feasibility happens before you spend on architectural design.
Design and structural engineering
Plans, elevations, 3D renderings, and structural engineering all go together. A homeowner sees the 3D renderings. The plan checker reads the structural calcs and the framing details. Both are required for a complete plan check submittal. Design and structural together typically take 8 to 12 weeks for a San Marino addition project.
Permits and plan check in San Marino
City of San Marino Building and Public Works. reviews building, structural, plumbing, mechanical, electrical, and energy calcs in one package. Design Review Committee reviews exterior work on every project. Front yard fence height limits, mature tree protections, and strict massing rules. Plan check rounds typically run 4 to 10 weeks. Bigger additions or projects in hillside or historic overlays run longer.
Construction window
Excavation, foundation, framing, MEP rough, dry in, insulation, drywall, finishes. Single story rear additions in San Marino typically run 5 to 8 months of construction. Second story projects run 7 to 12 months. Hillside lots with grading or foundation retrofit add time.
Specific considerations in San Marino
Mostly flat. Adjacent to the Raymond fault zone. For an addition project this drives foundation type, framing approach, and roof tie in scope.
How Paradigm Builders Can Help in San Marino
Paradigm Builders runs design, permits, and construction across the full residential scope in San Marino. Browse our service pages for what fits your project:
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