Andrea Costanzo Design — residential design for San Francisco Peninsula homeowners
Why choose Andrea
More Than Great Design. Experience That Gets Projects Approved.
A successful project requires more than beautiful plans. It takes experience navigating local planning departments, building codes, permits, and construction.
Since 2000, Andrea Costanzo has helped Bay Area homeowners move projects from concept to completion with confidence.
We guide you through every step—from the first sketch to city approvals and construction.
- Serving the Bay Area since 2000
- 100+ ADUs designed and completed
- Extensive experience in remodels, additions, and new homes
- Deep knowledge of local planning and permitting processes
- Personal guidance from design through construction
2000
Serving the Bay Area since
100+
ADUs designed and completed
25+
Years of residential design
ADUs
Maximize Your Property with an ADU
Whether you're creating space for family, generating rental income, or adding a private home office, Andrea has designed and overseen more than 100 ADU projects throughout the Bay Area.
Home Remodeling
Transform the Home You Already Love
From kitchens and bathrooms to whole-home renovations, we design spaces that improve the way you live while preserving what makes your home unique.
Additions & New Homes
Create More Space for What's Next
Whether you're expanding your current home or building a custom home from the ground up, we'll help create a design that fits your family, your lifestyle, and your future.
Selected work
Projects Across the Peninsula
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Our process
A Simple Process from Idea to Construction
- 01
Consultation
Share your goals, ideas, and vision.
- 02
Design
Develop plans tailored to your home and budget.
- 03
Permits
Navigate city reviews and approvals with confidence.
- 04
Construction Support
We'll stay involved throughout the building process.
Client testimonials
See what homeowners across the Peninsula have to say about working with Andrea.
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Meet Andrea
Local Experience You Can Trust
Since 2000, Andrea Costanzo has helped homeowners throughout the Peninsula improve the way they live through thoughtful residential design. Her combination of creative design, practical construction knowledge, and experience working with local cities helps clients move through the design and permitting process with confidence.
Ready to start?
Let's Talk About Your Project
Whether you're planning an ADU, remodeling your home, building an addition, or building a new home, we'd love to hear your ideas.