BAY AREARealty and Construction INC.

Additions · Mountain View

Home Addition Contractor in Mountain View

When you love your Mountain View street but need more house — room additions, primary suites, and second stories, engineered and built end to end.

Moving up in Mountain View means a property-tax reset and a higher-rate mortgage on top of selling costs. Adding the square footage you need to the home you already own — near Google, Microsoft, and the startups that keep values high — is frequently the stronger move.

Mountain View's housing — downtown Victorians, Monta Loma mid-centuries, Cuesta Park ranches — supports primary-suite additions, family-room bump-outs, and second stories where floor-area and daylight-plane rules allow. The city reviews larger projects for design compatibility, which experienced submittals clear cleanly.

Additions are real construction. We carry the project from feasibility sketch through final inspection — ten minutes from our Sunnyvale office.

Addition permits in Mountain View

Mountain View additions run through Development Services (500 Castro St.): a building permit plus zoning review of setbacks, floor-area ratio, and daylight planes; larger additions and second stories can trigger design-compatibility review. Typical plan check runs ~2–3 months for additions. School impact fees apply over 500 sq ft. We design to the objective standards from day one to avoid redesign rounds.

What’s included

Primary Suite Additions

The bedroom-bath-closet suite that transforms daily life and resale position.

Second Story Additions

Double the footprint without losing the yard — full structural engineering, within FAR and daylight-plane limits.

Room & Wing Additions

Family rooms, bedrooms, and in-law suites grafted seamlessly onto the existing structure.

Kitchen & Great-Room Bump-Outs

8–15 foot expansions that turn cramped kitchens into entertaining spaces.

Design-Compatibility-Ready

Submittals tuned to Mountain View's review so larger additions clear without redesign.

What it costs in Mountain View

2026 Mountain View addition cost ranges
ProjectTypical RangeNotes
Ground-floor addition$400 – $700 / sq ftComplexity and finish driven
Primary suite (350–500 sq ft)$180K – $320KIncludes full bath
Second story addition$500 – $800 / sq ftIncludes structural upgrades below
Bump-out (under 120 sq ft)$60K – $130KFoundation type dependent

Includes design, engineering, permits, and construction. School impact fees apply over 500 sq ft.

What we build in Mountain View

  • Primary-suite additions in Cuesta Park & Waverly Park
  • Second-story additions in Monta Loma
  • Family-room bump-outs in Rex Manor
  • In-law wing additions city-wide
  • Great-room expansions near downtown

Home Additions — full details

Process, scope, and everything our home additions service covers Bay Area-wide.

All services in Mountain View

Remodels, ADUs, permits, real estate, and financing across Mountain View.

Mountain View Home Additions FAQs

How much does a home addition cost in Mountain View?+

Roughly $400–$700/sq ft for ground-floor additions and $500–$800/sq ft for second stories in 2026. A 350–500 sq ft primary suite runs $180K–$320K including a full bath; bump-outs run $60K–$130K.

Will Mountain View's design review slow my addition?+

Larger additions and second stories can trigger design-compatibility and floor-area/daylight-plane review. We design within the objective standards from day one, which is how additions clear review without redesign rounds.

Addition or ADU in Mountain View?+

An addition expands your living space; an ADU is a rentable self-contained unit. Budgets are similar per square foot — we'll model both against your lot and goals.

Will my property taxes go up?+

Only on the addition's assessed value — Prop 13 protects your existing basis. A $250K addition adds roughly $2,800–$3,100/year, usually far less than a bigger-home purchase would trigger.

How long does a Mountain View addition take?+

Plan check ~2–3 months, then 3–6 months of construction. We're ten minutes away, so site management is tight.

Related Services & Guides

Planning home additions in Mountain View?

Honest numbers, one accountable team. We respond within one business day.

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