Home addition — Single-story addition Cost in San Diego, 2026

Why single-story addition × San Diego produces this band

A single-story addition scope for a home addition in San Diego combines two price levers: scope and metro labor rates. Single-story additions extend the existing footprint at grade — new foundation section, roof tie-in, and framing that matches the existing structure. No structural work on the original house beyond the tie-in. Against the national median remodel labor rate, San Diego runs 35% above the national median — so the single-story addition band comes in at the mid-range, then scales 35% above the national median on top of that. Permit timelines for residential work in San Diego typically run 6-14 weeks, which is the window you plan your design and decision sequence against. This page gives you the actual 2026 San Diego bands for this exact combination, plus the three cost drivers Baily asks about first when scoping the project live.

What drives cost for a single-story addition scope

• ·Foundation extension (slab or stem-wall to match existing)
• ·Roof tie-in flashing and structural connection
• ·Exterior siding match (often requires whole-elevation repaint)
• ·HVAC extension into the new zone

What makes San Diego different

• Labor — CSLB-licensed GC market with strong ADU-construction demand following SB 9 and SB 10.
• Labor — Coastal Commission jurisdiction adds project-management time for parcels west of the 1st public road.
• Labor — Military-base proximity generates steady remodel demand (off-base housing), keeping trades busy year-round.
• Material — Title 24 energy requirements same as LA — higher envelope + glazing spec.
• Material — Coastal corrosion protection required on hardware and fasteners within 1,500 ft of the ocean.

San Diego rules that affect this scope

• San Diego Development Services Department (DSD) handles plan check — timeline varies by review type and discretionary vs ministerial.
• Coastal Development Permit required within the Coastal Zone — adds 4-12 weeks.
• San Diego ADU Bonus Program allows additional ADUs above state minimums with deed-restricted affordability.
• Fire-prone hillside parcels subject to ember-resistant construction under Chapter 7A of California Building Code.

Scope your home addition with Baily.

Baily asks the eight questions that determine where your project lands inside the $189K-$432K band for San Diego and hands the scoped brief to one licensed builder.

Related pages

Questions LA homeowners actually ask

• What is the 2026 cost range for a single-story addition scope home addition in San Diego?

  $189,000-$432,000, with the median landing near $310,500. The range reflects finish tier and layout complexity within the single-story addition scope; the San Diego labor multiplier of 1.35× vs national median is baked in.

• How long does a single-story addition scope home addition take in San Diego?

  18-26 weeks of on-site construction for the single-story addition scope, plus 6-14 weeks of permit review in San Diego if the scope requires a permit. Cosmetic-only refreshes often skip permits; anything touching plumbing, electrical, or structural does not.

• What is the single biggest budget-overrun risk for this scope?

  Matching old siding or brick — if the material is discontinued, the whole elevation has to be reclad. $8-20K unexpected if not scoped up front.