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Hillsborough CA Real Estate & Homes For Sale

Hillsborough is a town in San Mateo County where the Architecture and Design Review Board reviews exterior design, including landscaping, fences and gates on major projects. Owners should also note separate tree-work and historic-review processes, and that town natural open space is preserved without public access.

Explore Hillsborough, CA real estate and homes for sale with this local guide. Contact Diamond to discuss your criteria and current property-search options.

At a glance
County	San Mateo County
Local government	Town of Hillsborough — Architecture and Design Review Board
Water and sewer	Town water system with interconnected pressure zones
Housing	Older residences and estate properties with large grounds
Local rules	ADRB design review; historic review; tree-work permits

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Hillsborough real estate at a glance

Hillsborough home comparisons should connect architectural character with the grounds, water service and the way the property is actually used. The town’s Architecture and Design Review Board considers exterior design, while separate resources address tree work and development applications. Town-owned natural open space also differs from a public recreation park: an open-looking backdrop does not automatically provide trail access. Compare the house, usable garden and neighboring landscape separately, then account for the specific building history and infrastructure rather than assuming all estate properties carry the same responsibilities.

Hillsborough home-search comparisons
Local setting or property	Practical difference	Useful comparison
Older residence	The town provides a historic-review application alongside development review.	Establish the particular building’s status before planning exterior changes. Planning applications
Major addition / grounds redesign	Design review can extend beyond the principal house.	Compare the proposed building, landscaping, fences and gates as one defined project. ADRB scope
Natural open-space edge	Town open-space areas are preserved and not open for public access.	Distinguish a landscaped outlook from a usable public route. Open-space management
Different topographic settings	The water system uses interconnected pressure zones.	Evaluate the home’s actual service and plumbing rather than a townwide pressure assumption. Town water-system study

Local source review: October 29, 2026. These are property-comparison considerations; current listings, travel times and individual project approvals require the specific address and current information.

Hillsborough homes: compare the residence with its grounds

A Hillsborough property comparison should explain both the house and the site supporting it. Larger interiors, grounds and accessory spaces can create useful options while adding different maintenance and record questions. Identify the features you will actually use before deciding which property offers more value to your move.

Hillsborough homes for sale

Hillsborough market report

Keep the site systems visible

Walk the relationship between parking, entry, outdoor living areas and detached structures. Where slope, retaining work or drainage features matter, collect the relevant plans and condition evidence. The visual size of a landscaped site cannot establish its future building capacity or maintenance budget.

For the residence, separate original construction from later additions and major replacements. A detailed improvement chronology is more useful than a broad renovation label, especially when rooms or accessory uses are central to your plans.

Buying in Hillsborough

Use the town resource identified by the county city directory. Establish the status of significant improvements and obtain a parcel-specific answer about any proposed change before assigning it value.

The county property workbook keeps residence, site and approval questions separate. Compare Burlingame or San Mateo where their actual homes meet your needs rather than treating all nearby addresses as the same property proposition.

Selling a Hillsborough property

Create a clear residence-and-grounds file with records for material alterations, site work and accessory spaces. Explain present use accurately and identify missing evidence. Show the areas buyers can comfortably use and the actual entry sequence.

The San Mateo County seller service connects those facts to preparation and pricing. Avoid presenting a conceptual project, separate amenity or unverified use as an established feature of the sale.

Types of property for sale in Hillsborough

Hillsborough is almost entirely single-family. In January 2024, Ordinance 792 replaced the old single residence district with three districts (Chapter 17.12):

RD-1, Traditional Residential: the town’s single-family neighborhoods. This covers nearly every home for sale.
RD-2, Mixed Residential: townhomes and multifamily housing on a limited number of parcels.
RD-3, Governmental and Residential Mixed Use: town facilities with a small number of homes on specific town-owned land.

Lots are large by rule. Under §16.08.010, the ordinary subdivision framework uses 21,780 square feet of net area, which is half an acre, not counting street or driveway easements. It also needs 150 feet of continuous street frontage and a 100-foot minimum width. Lots created legally under earlier rules remain valid. ADUs and SB 9 two-unit projects follow Chapters 17.52 and 17.54.

Luxury homes and estates in Hillsborough

In Hillsborough, high-end property is the standard housing type, so the planning questions matter more than any single amenity:

Design review. The Architecture and Design Review Board hears new houses, major additions, landscaping, street-facing fences and gates (Chapter 2.12).
Structure size and lot coverage. House size and lot coverage are capped under Chapter 17.32. Height is limited under Chapter 17.28. A large lot does not mean a proportionally larger house is allowed.
Lot splits. A conventional subdivision follows the applicable lot/frontage framework, while an eligible SB 9 urban lot split or other statutory pathway requires separate review. Do not apply the ordinary half-acre rule as a universal prohibition.
Historic homes. Historic and landmark houses have their own review. See our Carolands design history for an example.

Due diligence for an estate purchase:

Get the permit and design-review history of each addition, pool house and guest unit.
Have drainage and retaining walls reviewed.
Get tree-permit records before you plan any landscape changes.
Read any private-road or shared-driveway agreements.

Our Hillsborough estate site inspections and estate ownership budget guides list the documents. Insurance needs early attention; see insuring a high-value home, the FAIR Plan guide and our guest-house guide.

Many Hillsborough owners value privacy. Ask Diamond Real Estate Group which permitted private-marketing options fit your property, goals and the applicable MLS rules. Availability of any particular listing is not guaranteed. Related reading: discreetly. See San Mateo County luxury homes and estate-town design review.

Costs to plan for when buying in Hillsborough

Hillsborough has its own real property transfer tax under Chapter 3.20. Ask the San Mateo County Recorder or escrow to confirm the currently collected town/county allocation, taxable base, rounding and exemptions under Chapter 3.20. Under Revenue and Taxation Code §11931, a city tax at half the county rate is credited against the county tax. The combined amount is collected once at recording and split between the town and the county. Look up the current bill and any special assessments with the San Mateo County property tax lookup. See also our San Mateo County property tax page and sewer lateral requirements at sale.

Hillsborough real estate: questions people ask

What is the minimum lot size in Hillsborough?

The ordinary subdivision minimum is 21,780 net square feet, or half an acre; current state housing/subdivision pathways and code exceptions must be reviewed separately. A new lot also needs 150 feet of continuous street frontage (Municipal Code §16.08.010–.020). Narrower frontage is allowed on corner and cul-de-sac lots. Existing lots that were legally created under earlier rules keep their status.

Does Hillsborough have a transfer tax?

Confirm the currently collected town/county allocation with the Recorder or escrow. State law provides a county credit for a qualifying city tax adopted at one-half the county rate, rather than automatically adding both full amounts.

Can I add an ADU or a second home on a Hillsborough lot?

Accessory dwelling units and junior ADUs follow Chapter 17.52 of the town code, and two-unit projects under SB 9 follow Chapter 17.54. State law requires ministerial review of a qualifying ADU within 60 days of a complete application (HCD). Ask the town which design-review steps still apply to the unit’s exterior. See our ADU buying guide and SB 9 lot split guide. Review periods apply to qualifying complete applications and the applicable state pathway, with statutory exceptions; they do not guarantee that a proposed unit is feasible or that a building permit will be issued. Confirm the current requirements with the permit agency and HCD.

Is Hillsborough a city?

Hillsborough is an incorporated town in San Mateo County, with its own council, design review board, zoning and building permits. San Mateo County assesses property, records deeds and collects taxes.

Who can help me buy or sell in Hillsborough?

Diamond Real Estate Group works with Hillsborough buyers and sellers. See our estate comparable-sales analysis, read our Hillsborough realtors guide, or contact us.

Sources for this section

Hillsborough Municipal Code, Chapter 17.12, Zoning Districts (Ord. 792, 2024): https://library.municode.com/ca/hillsborough/codes/code_of_ordinances
Hillsborough Municipal Code, Chapter 16.08, Minimum Lot Size and Frontage: https://library.municode.com/ca/hillsborough/codes/code_of_ordinances
Hillsborough Municipal Code, Chapter 17.32, Residential Structure Size and Lot Coverage: https://library.municode.com/ca/hillsborough/codes/code_of_ordinances
Hillsborough Municipal Code, Chapter 2.12, Architecture and Design Review Board: https://library.municode.com/ca/hillsborough/codes/code_of_ordinances
Hillsborough Municipal Code, Chapter 3.20, Real Property Transfer Tax: https://library.municode.com/ca/hillsborough/codes/code_of_ordinances
California Revenue and Taxation Code §11931 (official California Legislature): https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=RTC&sectionNum=11931
San Mateo County Assessor-Clerk-Recorder, Property Tax Lookup: https://smcacre.gov/assessor/property-tax-look
California Department of Housing and Community Development, Accessory Dwelling Units: https://www.hcd.ca.gov/building-standards/adu

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Questions about buying and owning in Hillsborough

Does Hillsborough design review concern only the size of a new house?

No. The Architecture and Design Review Board describes review of new houses, additions, landscaping, fencing, gates along streets and other exterior changes. A future project therefore needs a coherent description of the house and grounds. When buying with a redesign in mind, compare the particular project with the town’s review resources instead of assuming an attractive architectural concept already answers the landscape and frontage questions.

Does an ADU follow exactly the same design-review path as a principal house?

Not necessarily. The town’s Planning Division distinguishes ADU review from administrative and ADRB review, and its application directory provides a separate ADU application. This matters when comparing a documented accessory dwelling with a pool house or studio. The intended use, current approvals and applicable standards should be established for the specific structure rather than inferred from its detached appearance.

Can a group of smaller trees matter even if no single trunk looks large?

Yes. Hillsborough’s tree-removal guidelines distinguish individual trees from groves and describe additional analysis where a proposed removal affects a grove. A proposed garden redesign should therefore consider the group’s setting and neighboring properties, not merely the largest trunk. Identify the actual scope of removal and associated construction before treating vegetation clearing as an ordinary maintenance item.

Do trees near the street follow the same process as trees deep inside a lot?

The town’s guidelines identify an encroachment-permit requirement for tree removal in the front right-of-way regardless of trunk size. They also distinguish removals linked to other improvements from independent tree work. That makes location and project scope important. A fence line or a tree’s position beside the driveway does not establish that it lies outside the town’s frontage requirements.

Can residents walk through all town-owned open space?

No. Hillsborough’s open-space management page expressly says these areas are not open to the public. It identifies natural lands including Crocker Lake and Spencer Lake as preserved assets. A home beside them can have a distinctive outlook without gaining a public trail or private recreation right. Compare the parcel boundary and permitted access rather than treating undeveloped land as an extension of the yard.

How do the town’s public parks differ from its natural open space?

The parks directory identifies usable destinations such as Crossroads Park, with benches and a fountain, separately from preserved open space. That is a useful distinction for a household planning everyday walks or time outside. Trace the actual route from the home to the particular public facility; nearby green land and an accessible neighborhood park can offer quite different experiences.

Where does Hillsborough’s drinking water come from?

The town’s water-supply page identifies SFPUC as its wholesale source, including Hetch Hetchy and local watershed supplies. The town then operates its local distribution system. For an estate with substantial grounds, separate household and landscape usage when reviewing the property’s actual service history. A regional source description does not establish the condition of private irrigation, service piping or fixtures at the home.

Why should topography be considered when evaluating water service?

The town’s water cost-of-service study describes interconnected pressure zones, pumps and storage serving varied elevations. That is useful infrastructure context, not a pressure warranty for any street. Compare the actual home’s service, regulating equipment and plumbing performance, particularly where multiple levels or extensive irrigation are important to the purchase. A hilltop view alone does not establish either inadequate or superior service.

Does a Hillsborough sale involve private sewer-lateral review?

The town’s sewer FAQ states that the lateral must be inspected when a home is sold and repaired or replaced if necessary. Its published utility-code provisions also address transfer-related testing, responsibilities and discretionary waivers. Establish the current process and property’s existing compliance history with the town; do not interpret a previous plumbing repair or a public-main improvement as automatic satisfaction of every transfer requirement.

Does being an older Hillsborough house automatically establish historic status?

Age, architectural appeal and formal historic status are different things. The town’s planning application directory includes a historic-review application, and its Planning Division addresses historic and environmental assessments. Identify the particular resource record before assuming either that all exterior changes are unrestricted or that no changes are possible. Compare the house’s character with the specific alterations you want, including windows, materials and additions.

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