Palo Alto

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ADU Builder in Palo Alto, CA

Palo Alto is one of Silicon Valley’s strongest housing markets. ADUs here can increase property value by 25 to 35 percent while generating steady rental income in a community with consistently high demand. Apex Homes provides complete in-house ADU design and construction services in Palo Alto, handling everything from feasibility and permits to the finished build. If you’re ready to move forward, we’ll start with a free feasibility study and tell you exactly what’s possible on your lot.

ADU Regulations in Palo Alto

Palo Alto allows ADUs on both single-family and multi-family lots, though requirements differ depending on lot type.

Single-family lots (R-1)

  • Units allowed: One detached or attached ADU + one JADU (up to 500 sq ft)
  • Size: Up to 900 sq ft for 1-bedroom layouts; up to 1,000 sq ft for 2+ bedrooms
  • Setbacks: Detached — 3 ft min from main home; attached — 4 ft side and rear
  • Height: Attached — up to 25 ft (or zone max); detached — up to 45 ft (RE zones) / 30 ft (OS zones)

Multi-family lots

  • Units allowed: Up to 2 detached ADUs + attached ADUs up to 25% of existing units
  • Size: Detached ADUs — 150 sq ft minimum, no maximum; JADUs up to 500 sq ft
  • Setbacks: 4 ft side and rear (front per zoning); 3 ft min separation from primary dwelling
  • Height: Up to 16 ft; up to 18 ft within ½ mile of transit or if main structure is multi-story

Palo Alto offers fee waivers for ADUs under 750 sq ft and expedited review timelines — making smaller units especially cost-effective to build.

Apex Homes handles zoning verification, setback calculations, and code compliance — included in your free feasibility study.

Build Your ADU in Palo Alto

Start with ParcelZ. Enter your address and get instant eligibility, your buildable area, and matching floor plans. Free, no signup. Then our team takes it from there.

Palo Alto ADU Permitting Process

To obtain an ADU permit in Palo Alto, homeowners should first confirm their property’s zoning and review the city’s ADU standards.

Free Feasibility Study

Apex checks your zoning, lot size, setbacks, and utility connections — at no cost, before you commit to anything.

Pre-Application Meeting

A meeting with Palo Alto’s Planning Department to confirm zoning, setbacks, and design compatibility before submitting.

Apex Prepares Your Permit Package

We prepare all required documents — architectural plans, structural calculations, site layouts, utility connections, and the New Single-Family Residence / Detached ADU Checklist.

Submit via ACA Portal

Applications are filed online through the Accela Citizen Access (ACA) portal. A project coordinator is assigned to confirm completeness. Plan review typically takes 2–3 months.

Construction & Inspections

Permits are issued electronically after approval. Apex builds your ADU and manages all city inspections, delivering a finished, move-in ready unit — typically within 5 months of your feasibility study.

Check my Property Eligibility


Browse ADU Floor Plans

Apex offers a range of 1, 2, and 3-bedroom ADU floor plans designed to meet California’s building standards and fit a variety of lot sizes. Each plan includes all documentation required for permitting — site plan, elevations, structural details, and Title 24 compliance.

View All Pre-Approved ADUs

Does a plan fit your lot?

Use ParcelZ to instantly see which of these plans fit your property in Palo Alto — free, no signup.

Why Build An ADU in Palo Alto?

Palo Alto is one of Silicon Valley’s strongest housing markets, and ADUs provide significant advantages for homeowners. An ADU can increase property value by 25 to 35 percent while offering steady rental income in a community with consistently high demand.

ADUs also provide flexible living options, making them perfect for aging parents, adult children, or caretakers who need independence but want to remain close to family. With Palo Alto’s incentives, such as fee waivers for ADUs under 750 square feet and expedited review timelines, homeowners can take advantage of faster or more cost-efficient construction compared to traditional housing projects.

Have questions? Contact Apex Homes Today

Our team knows Palo Alto’s zoning, permits, and pricing inside out. Call us for a free, no-pressure conversation about your property. We’ll tell you exactly what’s possible.


FAQs

How much does an ADU unit cost in Palo Alto?

Typical costs range from $300–$350 per square foot with Apex Homes predesigned ADU floor plan.

What is the maximum size of an ADU in Palo Alto?

Studio and one-bedroom ADUs can be built up to 850 sq ft, while two-bedroom or larger units can go up to 1,000 sq ft. In most cases, both detached and attached ADUs follow these size limits, though detached units may be allowed slightly larger under certain conditions.

Can I choose upgraded interior materials in Palo Alto?

Yes, we provide upgraded interior options for all of our ADU models.

Can I build more than one ADU in Palo Alto?

Yes! You can build more than one ADU in Palo Alto, but it depends on your lot type.

For single-family lots, you may have one ADU plus one JADU (Junior ADU). JADUs must be created within the primary dwelling and have specific owner-occupancy requirements if included.

For multi-family properties, such as duplexes or triplexes, you may add ADUs for up to 25% of the existing units, or at least one additional ADU, depending on site capacity and local zoning regulations.

Can I have financial options for my ADU in Palo Alto?

Yes, we work directly with lenders to simplify your ADU journey.