TYPES OF HOME ADDITIONS IN MARIN COUNTY
The most common home addition types we build in Marin County include rear additions (extending the back of your home into the yard — the most popular and cost-effective option), second-story additions (adding a full or partial upper level — ideal when lot coverage is maxed out), bump-out additions (smaller expansions of 100–400 sq ft for a specific room like a kitchen or bathroom), and primary suite additions (master bedroom, bathroom, and walk-in closet additions — extremely popular in Marin). Each type requires careful consideration of your lot coverage allowances, setback requirements, and the specific regulations of your Marin County city.
Home addition costs in Marin County typically run $400–$700/sq ft for mid-range work and $700–$1,200/sq ft for luxury finishes. A 400 sq ft rear addition might cost $180,000–$300,000. A full second-story addition of 800 sq ft might cost $500,000–$900,000. Our in-house structural engineers design addition foundations and framing, our architects handle permit drawings, and our project managers coordinate every subcontractor. We serve all Marin County cities — Tiburon, Mill Valley, Sausalito, San Rafael, Corte Madera, Larkspur, Kentfield, Ross, and more.