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

$283,500-$648,000, with the median landing near $465,750. The range reflects finish tier and layout complexity within the second-story addition scope; the San Diego labor multiplier of 1.35× vs national median is baked in.

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

28-42 weeks of on-site construction for the second-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?

Foundation inadequacy — if the existing foundation can't carry the new load, underpinning or new footings add $25-50K and 4-8 weeks.

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

Low

$284K

$283,500

Median

$466K

$465,750

High

$648K

$648,000

Scope timeline: 28-42 weeksSan Diego permit window: 6-14 weeksUpdated 2026-04-24

Why second-story addition × San Diego produces this band

A second-story addition scope for a home addition in San Diego combines two price levers: scope and metro labor rates. A second-story addition requires the existing foundation to be verified (sometimes reinforced), structural beam and column work to carry the new load, a new roof replacing the old, and a new staircase. Most complex addition type. Against the national median remodel labor rate, San Diego runs 35% above the national median — so the second-story addition band comes in 50% above 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 second-story addition scope

·Structural engineer for load path + foundation capacity
·Full existing-roof removal and new roof install
·New staircase location (often forces a first-floor layout change)
·Weather protection of the existing house during construction

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 $284K-$648K band for San Diego and hands the scoped brief to one licensed builder.

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Questions LA homeowners actually ask

$283,500-$648,000, with the median landing near $465,750. The range reflects finish tier and layout complexity within the second-story addition scope; the San Diego labor multiplier of 1.35× vs national median is baked in.