How Much Does It Cost to Build a Custom Home in Hillsborough? (2026)

What Does It Cost to Build a Custom Home in Hillsborough?

Hillsborough is one of the most exclusive residential communities in the San Francisco Bay Area. Located in San Mateo County between Burlingame and San Mateo, the town is entirely residential, with no commercial zones, no retail, and no multi-family housing. Every property is a single-family home, and the half-acre minimum lot size ensures that the community maintains its estate-scale character. Hillsborough’s tree-lined streets, bay views, and proximity to both San Francisco and Silicon Valley make it a perennial destination for affluent homeowners.

Custom home construction in Hillsborough costs $400-$700+ per square foot in 2026. The town’s design review process, large lot sizes, and the finish expectations set by a market where homes regularly sell for $5M-$15M+ all contribute to construction costs that exceed most Bay Area communities.

All pricing is approximate, reflects 2026 Bay Area market conditions, and is subject to change. Every project is unique. Final costs are determined on a project-by-project basis during our design phase.

For Bay Area-wide custom home pricing, see our custom home cost guide.

Cost Per Square Foot by Build Tier

Hillsborough’s construction market serves a premium clientele that expects quality materials, thoughtful design, and finishes that match the community’s standards. Here is what each tier looks like in 2026.

Build Tier	Cost Per Sqft	3,500 Sqft Home	5,000 Sqft Home	What to Expect
Standard Custom	$400-$500/sqft	$1.4M-$1.75M	$2.0M-$2.5M	Quality finishes, efficient design, standard systems
Mid-Range Custom	$500-$600/sqft	$1.75M-$2.1M	$2.5M-$3.0M	Premium materials, architectural detailing, smart home integration, custom cabinetry
Luxury Custom	$600-$700+/sqft	$2.1M-$2.45M+	$3.0M-$3.5M+	Ultra-premium finishes, complex architecture, full home automation, imported materials

These ranges cover hard construction costs. Land, architecture, engineering, permits, landscaping, pool, and soft costs are additional.

Total Project Cost Breakdown

Here is how total project costs typically break down for a Hillsborough custom home.

Cost Category	Percentage of Total	Typical Range
Land acquisition	35-50%	$3M-$10M+
Hard construction	30-40%	$1.6M-$3.5M+
Architecture and engineering	8-12% of construction	$130K-$420K
Permits, fees, and inspections	3-5% of construction	$50K-$175K
Landscaping, pool, and hardscape	8-12% of construction	$130K-$420K
Contingency	5-10% of construction	$80K-$350K

Land is the largest single expense. Properties in Hillsborough range from $3M for a smaller lot that needs a complete teardown to $10M+ for a prime lot with sweeping bay views.

What Drives Custom Home Costs in Hillsborough

Architecture and Design Review Board (ADRB)

Hillsborough’s ADRB reviews all new residential construction, major additions, and exterior modifications. The board evaluates projects based on compatibility with neighborhood character, architectural quality, lot utilization, and landscaping. This process is one of the defining aspects of building in Hillsborough.

The ADRB process affects costs in several ways:

• Design investment. Submissions require detailed architectural drawings, material specifications, color boards, and landscape plans. Architects experienced with the ADRB typically charge 10-15% of construction costs, reflecting the additional design work required.
• Timeline extension. The review process adds 3-6 months to the pre-construction schedule. Straightforward projects with designs that clearly align with neighborhood character move faster; projects that require revisions or generate neighbor concerns can take longer.
• Design modifications. The board may request changes to massing, roofline, exterior materials, or landscaping. These modifications can increase design costs by $10,000-$30,000 and sometimes affect construction costs if materials or structural elements change.

Despite the added time and cost, the ADRB process protects property values by maintaining the quality and character of the community.

Large Lot Sizes and Estate-Scale Building

Hillsborough’s half-acre minimum lot size means that custom homes are built at a scale that goes beyond just the house itself. A typical Hillsborough estate project includes:

• The main residence (3,500-7,000+ sqft)
• Swimming pool and outdoor living areas ($150,000-$500,000+)
• Detached or attached guest quarters where permitted
• Multi-car garages (3-4+ bays)
• Extensive landscaping on half-acre to multi-acre lots ($100,000-$400,000+)
• Driveways, motor courts, and pathways ($30,000-$100,000+)

The estate elements beyond the main home can add 20-40% to the overall project budget.

View Lots and Hillside Terrain

Many of Hillsborough’s most desirable properties sit on elevated lots with views of the San Francisco Bay, the city skyline, or the surrounding hills. These view lots command premium land prices and often involve hillside construction that adds to building costs.

Hillside-specific costs include:

• Grading and earthwork ($40,000-$150,000+)
• Retaining walls ($30,000-$120,000+)
• Engineered foundations for sloped terrain (pier-and-beam systems cost 2-3x standard slab foundations)
• Enhanced drainage systems to manage water flow on sloped lots ($20,000-$60,000)

Flat lots in the lower portions of Hillsborough build at the lower end of per-sqft ranges, while elevated view lots push costs toward the upper end.

Premium Finish Standards

Hillsborough’s market sets a high bar for interior and exterior quality. Custom homes in this community are expected to include:

• Natural hardwood or stone flooring throughout
• Quartzite, marble, or premium stone countertops
• Professional-grade appliance suites (Sub-Zero, Wolf, Thermador)
• Custom cabinetry and built-in millwork
• Multi-zone HVAC systems with air filtration
• Whole-home automation for lighting, HVAC, security, and audio
• High-performance window systems (wood-clad or steel-frame)

These finishes account for $140-$250+ per square foot of total build cost. Homes built with finishes below market expectations will not compete at resale in a community where comparable properties sell for $8M-$15M.

Seismic Requirements

Hillsborough, like all Bay Area communities, sits in one of the most seismically active regions in the world. New construction must meet California’s current seismic standards, including engineered lateral force-resisting systems. Geotechnical investigations ($6,000-$15,000) are standard for new construction, particularly on hillside lots where soil stability and slope performance must be evaluated.

Hillsborough vs. Nearby Cities

City	Standard Custom	Mid-Range	Luxury
Hillsborough	$400-$500/sqft	$500-$600/sqft	$600-$700+/sqft
Atherton	$500-$650/sqft	$650-$800/sqft	$800-$1,000+/sqft
Woodside	$400-$500/sqft	$500-$600/sqft	$600-$700+/sqft
Burlingame	$350-$425/sqft	$425-$500/sqft	$500-$575/sqft
San Mateo	$300-$375/sqft	$375-$450/sqft	$450-$500/sqft
Menlo Park	$350-$425/sqft	$425-$500/sqft	$500-$550+/sqft

Hillsborough’s costs are comparable to Woodside and below Atherton. Compared to neighboring Burlingame and San Mateo, Hillsborough commands a 15-30% premium due to larger lot sizes, the design review process, and higher finish expectations.

Sample Budget: 4,500 Sqft Custom Home in Hillsborough

Here is a realistic budget for a mid-range custom home on a half-acre Hillsborough lot with gentle terrain and partial bay views.

Line Item	Estimated Cost
Land (half-acre lot)	$4,500,000
Demolition (if existing structure)	$55,000
Architecture and engineering	$275,000
ADRB design review preparation	$15,000
Permits and fees	$95,000
Hard construction (4,500 sqft at $550/sqft)	$2,475,000
Swimming pool and outdoor living	$250,000
Three-car garage with finished interior	$150,000
Landscaping and hardscape	$250,000
Contingency (10%)	$247,500
Total estimated project cost	$8,312,500

This budget represents a well-executed home in a desirable part of Hillsborough. Prime view lots with larger homes, extensive estate amenities, and ultra-luxury finishes can push total budgets past $12M-$15M.

Why Custom Home for Your Hillsborough Project

Custom Home’s two-phase process aligns perfectly with Hillsborough’s building environment, where design quality matters and the ADRB sets high standards for every new home.

Phase 1: Design. We create complete 3D visualizations of your home and estate, showing every room, every material, every exterior detail, and the relationship between the home and the landscape. This visualization becomes a powerful tool for the ADRB review process, helping the board understand your design intent. We deliver an itemized budget with no hidden costs, no allowances, and no placeholders.

Phase 2: Build. Construction proceeds from fully approved plans with locked-in pricing. For a Hillsborough project with a $2-3M construction budget, eliminating change orders and scope creep typically saves 10-15%, representing $200,000-$450,000 in avoided cost overruns.

Custom Home is licensed by the California Contractors State License Board (CSLB #986048) and has been building custom homes across the Bay Area since 2005.

Start Planning Your Hillsborough Custom Home

Building in Hillsborough means building for a community that values quality, character, and enduring design. The right approach starts with understanding the ADRB process, evaluating your lot’s potential, and working with a builder who can deliver a home that meets both your expectations and the community’s standards.

Contact Custom Home for a free consultation to discuss your Hillsborough custom home project. We will review your lot, discuss your design vision, and provide a preliminary cost range so you can plan your Hillsborough estate with confidence.