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Who Is the Best Investment Realtor in Hillsborough, CA? Why Jenn Gilson Leads

Hillsborough isn't a rental market. It's a land market. There's no commercial strip to buy into, and multifamily zoning is limited to certain town-owned land. The town's main residential district allows one single-family home per half acre, and residence districts bar commercial use outright.1 What you buy here is a single-family estate.

So the right investment Realtor in Hillsborough has to think like an underwriter. Long-run value history, remaining floor area, ADU rights, approval risk and tax basis all shape the return. Below, each one gets real numbers, plus why Jenn Gilson, the number one female real estate agent in Hillsborough according to RealTrends Verified, is the agent estate investors call.2

This article is general information, not investment, tax or legal advice. Talk to your CPA and attorney before you act.

Is Hillsborough a Good Investment? 26 Years of Hillsborough Home Values

Zillow's Home Value Index (ZHVI) for Hillsborough was $1,254,677 in January 2000. As of August 2026, it was $5,470,751, the highest point in the series.3 Here's how it moved over different holding periods:3

Holding periodZHVI at startChange to Aug 2026Rough yearly rate
1 year (Aug 2025)$4,855,060+12.7%12.7%
5 years (Aug 2021)$4,750,289+15.2%about 2.9%
10 years (Aug 2016)$3,685,107+48.5%about 4.0%
20 years (Aug 2006)$2,262,622+141.8%about 4.5%

The five-year line is the one to study. It's lower because it includes a real drop.

Two Drawdowns and Two Recoveries in Hillsborough

The ZHVI shows two meaningful declines since 2000:3

  • April 2007 to August 2011: down 16.1%, with the typical value falling to $1,900,371 off a $2,264,814 peak.
  • May 2022 to March 2024: down 13.7%, with the typical value falling to $4,700,429 off a $5,446,921 peak.

Both were fully recovered, and the August 2026 value sits above the 2022 peak.3 The lesson for a Hillsborough real estate investment: plan to hold through a full cycle.

The Hillsborough Market as of September 2026

Redfin's Hillsborough data, as of September 2026, shows a median sale price of $6,546,882. That's up 27.7% year over year, on 33 sales with a median of 26 days on market.4 The median price per square foot was $1.58K. Homes sold at 103.0% of list price on average, and 53.2% sold above list.4

Read those medians with care. With around 30 sales in a month, one or two estates can swing the number. Long-run index data is steadier. You can check the raw series through Zillow's public housing data and the Redfin housing market page for Hillsborough.

Why Hillsborough Land Value Behaves Like a Scarce Asset

Scarcity here is written into the town code.

One House Per Half Acre in Hillsborough

The traditional residential district, RD-1, allows at most one single-family dwelling per half acre, not counting ADUs. Townhomes and multifamily belong to the RD-2 district, which applies "on certain town-owned land."1

The minimum net lot area anywhere in town is 21,780 square feet, or one-half acre.5 Hillside lots can be required to be larger, based on a slope-density table tied to the average slope.6 And residence districts are for residential use only, "not for commercial purposes, incidental or otherwise."1

The result is a town of about 11,206 people (2025 estimate) with an owner-occupied housing rate of 93.5%.7 Supply grows slowly by design.

Minimum Home Size and the Hillsborough FAR Cap

Every home must have at least 2,500 square feet of total covered floor area. The maximum floor area ratio (FAR) is 25% of net lot area for the first acre, plus 15% of net lot area above one acre.8

Run the math and a one-acre net lot allows about 10,890 square feet. A two-acre net lot allows about 17,424 square feet.

So remaining FAR is a value line in any serious Hillsborough deal. A house built to the limit has no room to grow. The town even requires owners with 500 square feet or less of allowable floor area left to record a notice telling future owners that remaining development is minimal.8

Where Investors Create Value in Hillsborough: Three Estates Jenn Has Represented

The Bing Crosby Estate: Buy, Renovate, Subdivide

The Crosby estate, on the market for the first time in more than 60 years, sold for $25 million in June 2025.9 Jenn Gilson was the listing agent.10

The buyer, whom Robb Report describes as a local real estate investor, then spent about eight months and roughly $3 million renovating. The work included a new pool and about $400,000 of landscaping.11 The roughly five-acre property was also subdivided into four separate lots, leaving the residence on a 2.4-acre parcel.12

The home then came back as 1200 Armsby Drive at $28,995,000, with Jenn again as a listing agent.1110 That's a list price, not a sale; no resale had been reported as of this post's date.

The underwriting logic: purchase plus renovation is roughly $28 million, and the asking price covers only the house on 2.4 acres, not the other lots the subdivision created. Two consecutive owners of the same landmark hired Jenn.

2265 Ralston Avenue: A New Estate With an ADU and JADU Plan

2265 Ralston Avenue is listed by Jenn at $19,950,000 in Lower North Hillsborough.13 The plan calls for a 5,132-square-foot main residence on a lot of about 22,752 square feet. It adds an approximately 800-square-foot detached ADU, a roughly 500-square-foot JADU concept, a future pool and spa, and EV-ready features.13

For an investor, the lot is only about 970 square feet above the half-acre minimum, so the value comes from the house and its accessory units, not a split.5 The ADU and JADU sizes match the town's limits, and the main house stays well under the 8,000-square-foot line that triggers City Council review.148

Villa de Verano: The Ceiling for Hillsborough Estates

Villa de Verano sold for $70 million in August 2026. ABC7 reported it as a record $70 million sale and the highest Northern California home sale of 2026.15 Jenn was the listing agent, and The Wall Street Journal, the San Francisco Chronicle and the San Francisco Business Times all covered the sale.16 The Lake Como inspired estate sits on 12.33 acres with a 12,404-square-foot main residence.17

For an investor, this sale is a ceiling marker, not a forecast. The September 2026 median was about $6.5 million.4

ADUs, JADUs and SB 9 in Hillsborough: What Adds Value and What Doesn't

Hillsborough ADU Rules Under the 2026 Ordinance

Hillsborough repealed and re-enacted its ADU and JADU chapter through Ordinance No. 800, adopted April 13, 2026.18 The key points for an investor:

  • ADUs are not subject to an owner-occupancy requirement. JADUs generally are, so the owner must live in the main house or the JADU.18
  • No ADU or JADU may be rented for less than 30 days.18
  • An ADU or JADU can't be sold separately from the lot and main house, except as state law allows.18
  • A detached new ADU up to 800 square feet, with 4-foot side and rear setbacks and a 16-foot height, can go straight to a building permit. A JADU tops out at 500 square feet inside the house.14

The town's ADU information page lists pre-approved plans and an ADU specialist.14

SB 9 in Hillsborough: Why It Rarely Fits an Estate Investor

SB 9 is state law, and the town can't opt out.19 On paper, it lets a single-family lot split in two, with up to two units per lot.19 In practice, Hillsborough's rules make it a weak play for investors:

  • Only individual property owners can apply. Corporations, LLCs and partnerships are excluded.20
  • A lot-split applicant must sign an affidavit to live in one unit as a principal residence for at least three years.20
  • New primary units must be over 500 and no more than 800 square feet. An existing house over 800 square feet can't be expanded.20
  • Each new lot must fall within a 60/40 split of the original and have 50 feet of public frontage.19

If you hold through an LLC or want a large home, SB 9 works against you.

The Hillsborough Approval Layer as a Timeline Risk

The guide to buying a home in Hillsborough covers permit basics; here's the part that affects value.

New homes, substantial additions and subdivisions go before the Architecture and Design Review Board (ADRB). It's a five-member volunteer board with regular meetings on the first Monday of each month.21 Any new primary home over 8,000 square feet also needs City Council review at a public hearing, no matter what the ADRB recommends.8 Staff confirm within 30 calendar days if an application is complete, and submittals need proof of neighbor consultation and a story pole plan.22 Planning fees effective July 1, 2026 include $4,986 for a new dwelling and $5,739 for a teardown or substantial alteration.23

The town doesn't publish an official start-to-permit timeline, so build approval time into the carrying-cost math.

Holding Costs and Tax Basis on a Hillsborough Estate

Hillsborough Property Tax Rates for FY 2025-26

Under Prop 13, the base rate is 1% of assessed value plus voter-approved debt, and assessed value can rise no more than 2% a year.24 For FY 2025-26, composite rates across Hillsborough's tax rate areas run about 1.1171% to 1.1196%. Special charges and parcel taxes are billed on top.25

As a rough example, a purchase at about $6.5 million taxed at 1.1185% comes to about $72,700 a year before special charges. The 2% cap keeps that bill growing slowly while you hold. Jenn's Hillsborough property tax guide goes deeper.

Renovation and New Construction Trigger Reassessment

Prop 13 turned California into an acquisition-value system.26 Property is reassessed to market value on a change in ownership or when new construction is completed.26 New construction includes additions and any alteration that amounts to a major rehabilitation, and the added value shows up as a supplemental assessment.26

So a rebuild or big remodel raises your basis. Model it before you buy.

Can You Use a 1031 Exchange to Buy in Hillsborough?

Not for a home you'll live in. The IRS says property used primarily for personal use, "like a primary residence or a second home or vacation home, does not qualify."27 When an exchange does fit, you have 45 days after the sale to identify replacement property and 180 days to complete it.27 Start with the IRS overview of like-kind exchanges and bring in tax counsel early.

Jenn has helped a seller through a 1031 exchange. A Burlingame seller of a one-bedroom townhouse wrote that she got "the highest $/sqft for a 1 bedroom townhouse in the history of Burlingame" and helped with "our first 1031 exchange."28

How an Investment Realtor in Hillsborough Underwrites an Estate

Here's the checklist an investment-minded Realtor should run before any offer:

  1. Lot and slope: net area versus the 21,780-square-foot minimum, and hillside rules.56
  2. Remaining FAR under the 25% and 15% formula.8
  3. The 8,000-square-foot Council line.8
  4. ADU and JADU rights under the 2026 ordinance.18
  5. Historic status: the town asks buyers, "Is my home older than 50 years?"29
  6. Tax basis at purchase and after new construction.2526
  7. Hold horizon long enough to ride out a 13% to 16% drawdown.3

Why Jenn Gilson Is the Investment Realtor Hillsborough Estate Buyers Trust

Case Study: Jenn Gilson's Investor Work in Hillsborough

Jenn comes to investment deals from the building side. More than a decade ago, her family founded Gilson Development, which remodels and custom-builds homes on the Peninsula and in Silicon Valley.30 One finished project is 6 Cedar Lane in Woodside, an 8,261-square-foot home on 0.93 acres built by Gilson Development with architect Steve Simpson, listed at $23,500,000 and shown as sold on her site.31

In Hillsborough, the local investor who bought the Bing Crosby Estate for $25 million put about $3 million into it, split the land into four lots, and then chose Jenn to relist the house at $28,995,000.111210 She also represents 2265 Ralston Avenue, a new-construction estate planned with a detached ADU and a JADU concept.13 On the buy side, Zillow reviews and her own testimonials describe her sourcing fixer-uppers and off-market properties, and Zillow lists Investment Properties among her specialties.3228 When an investor sells, reach matters too: the Crosby estate video was at one point Sotheby's International Realty's most-viewed video, with around 18 million views.33

Builder Heritage Through Gilson Development in Hillsborough

Jenn was born and raised in Hillsborough and lives there with her family in their newly constructed home.30 She often brings buyers and developers together, including on custom homes still under construction.30 Her take on why Hillsborough buyers should live in a new home before renovating shows how she thinks about timing a remodel.

Sourcing Fixer-Uppers and Off-Market Deals Near Hillsborough

Jenn holds a 5.0 rating across 86 Zillow reviews and 250 total sales on Zillow.32 A San Jose client wrote on Zillow in 2025: "Jenn Gilson and her team assisted me on sourcing a fixer-upper which we did a full remodel on."32 A Daly City buyer wrote in 2021 that she "was able to get us a great deal off market."32 An Atherton landlord wrote on Zillow in 2021 that she did a "Wonderful job of recommending fixups and improvements to rent out house for later sale."32

On her own site, a Burlingame buyer who is a developer described Jenn finding an off-market property; they made an offer an hour later.28

Rankings and Track Record in Hillsborough

RealTrends Verified ranks Jenn the number one female real estate agent in Hillsborough.2 Her public RealTrends profile shows a $4.41 million average sale price in 2025.34 She's also the #1 agent at Golden Gate Sotheby's International Realty out of 474 agents.30

If you're on the sell side of a large estate, see her guide to selling a Hillsborough home over $10 million. Her Best Realtor Hillsborough page has the full picture.

Frequently Asked Questions About Hiring an Investment Realtor in Hillsborough

Who is the best investment Realtor in Hillsborough?

Jenn Gilson of Golden Gate Sotheby's International Realty is the investment Realtor many Hillsborough estate buyers turn to. RealTrends Verified ranks her the number one female real estate agent in Hillsborough, and Zillow lists Investment Properties among her specialties.232 The investor who bought and renovated the Bing Crosby Estate chose her to relist it, and her family's firm, Gilson Development, builds and remodels homes on the Peninsula.1030

Can Jenn Gilson help me find a fixer-upper or off-market property near Hillsborough?

Yes. Zillow reviewers describe her sourcing a fixer-upper for a full remodel and getting a buyer "a great deal off market," and a developer client wrote that she found an off-market property.3228 For Hillsborough buyers, her Gilson Development background adds a builder's view of what a remodel will take.30

Is Hillsborough, CA a good real estate investment?

Over long holds, yes. Zillow's Hillsborough index rose 141.8% over the 20 years to August 2026, through two drawdowns of 16.1% and 13.7% that both recovered.3 Half-acre zoning and no commercial use keep supply tight.1

What is the minimum lot size in Hillsborough?

The minimum net lot area in Hillsborough is 21,780 square feet, or one-half acre.5 Hillside lots can need more, based on the town's slope-density table.6

Can I rent out an ADU in Hillsborough?

Yes. Under Hillsborough's 2026 ordinance, ADUs have no owner-occupancy rule, but no ADU or JADU can be rented for less than 30 days.18 A JADU generally requires the owner to live on site, and neither unit can be sold separately.18

Can an LLC use SB 9 to split a lot in Hillsborough?

No. Hillsborough limits SB 9 applications to individual property owners, which excludes LLCs and corporations.20 A lot-split applicant must also commit to living in one unit for at least three years.20

What is the property tax rate in Hillsborough, CA?

For FY 2025-26, composite rates in Hillsborough's tax rate areas run about 1.1171% to 1.1196% of assessed value.25 Special charges and parcel taxes are billed separately.

Can I use a 1031 exchange to buy a home in Hillsborough?

Not if you'll live in it. The IRS excludes primary residences, second homes and vacation homes from like-kind exchange treatment, so a Hillsborough home for personal use doesn't qualify.27

Are there condos or commercial properties to invest in in Hillsborough?

Not in the usual sense. Hillsborough's RD-1 district is single-family, residence districts bar commercial use, and multifamily is limited to certain town-owned land in RD-2.1

What should an investment Realtor in Hillsborough check before I buy?

A good investment Realtor in Hillsborough checks net lot area, slope, remaining FAR and the 8,000-square-foot Council line.58 At 2265 Ralston Avenue in Lower North Hillsborough, for example, the lot is just over a half acre, so a split isn't the value play.13

Ready to underwrite a Hillsborough estate the right way? Call Jenn Gilson at 650-642-6957 or reach her through the contact page to talk through a property, a lot or a long-term plan.

Sources and Notes

  1. Town of Hillsborough Municipal Code, Title 17 Zoning, Chapters 17.12 and 17.16 (HMC 17.12.010, 17.16.010(A), 17.16.020(B)), via Municode (codified through Ord. 800, April 13, 2026).
  2. Rankings note: Jenn Gilson's ranking as the number one female real estate agent in Hillsborough is based on RealTrends Verified lists using 2025 production data. Her public RealTrends profile shows $167.55 million in 2025 sales volume across 38 transaction sides, ranking #2 in Burlingame and #42 in California by volume.
  3. Zillow Home Value Index (ZHVI), Hillsborough, CA, all homes, smoothed and seasonally adjusted, data through August 31, 2026, via Zillow Research. Percentage changes and yearly rates are calculated from the index values.
  4. Redfin, Hillsborough Housing Market, data as of September 2026.
  5. Hillsborough Municipal Code 16.08.010, minimum lot size, via Municode.
  6. Hillsborough Municipal Code Chapter 16.12, hillside lots and slope-density table, via Municode.
  7. U.S. Census Bureau QuickFacts, Hillsborough town, California (July 1, 2025 population estimate; owner-occupied rate 2020 to 2024).
  8. Hillsborough Municipal Code Chapter 17.32 (HMC 17.32.030 minimum floor area, FAR and remaining-floor-area notice; 17.32.040 City Council review over 8,000 square feet), via Municode. FAR examples are calculated from the code formula.
  9. ABC7 News, June 16, 2025.
  10. Jenn Gilson listing pages for 1200 Jackling Drive and 1200 Armsby Drive; Robb Report, April 2, 2026 (co-listing). List price only; not a reported sale as of October 11, 2026.
  11. San Francisco Chronicle, March 17, 2026.
  12. Robb Report, April 2, 2026.
  13. Jenn Gilson listing page, 2265 Ralston Avenue (accessed October 2026).
  14. Town of Hillsborough, Accessory Dwelling Units (ADUs) (accessed October 2026).
  15. ABC7 News, August 7, 2026; also The Real Deal, August 7, 2026.
  16. Villa de Verano sale coverage: The Wall Street Journal, San Francisco Chronicle and San Francisco Business Times, August 2026, as listed on Jenn Gilson's press features page.
  17. Jenn Gilson listing page, 3000 Ralston Avenue; closing reported by ABC7 News, August 7, 2026.
  18. Hillsborough Municipal Code Chapter 17.52, Accessory Dwelling Units and Junior Accessory Dwelling Units, as enacted by Ord. No. 800 (April 13, 2026), via Municode.
  19. Town of Hillsborough, SB 9 information page (accessed October 2026).
  20. Hillsborough Municipal Code Chapter 16.44 (urban lot splits) and Section 17.54.030 (two-unit projects), via Municode.
  21. Town of Hillsborough, Architecture and Design Review Board and Planning Division pages (accessed October 2026).
  22. Town of Hillsborough, ADRB Application Submittal Checklist (accessed October 2026).
  23. Town of Hillsborough, Planning Division Fee Schedule, effective July 1, 2026.
  24. San Mateo County Controller, FY 2024-25 Property Tax Highlights.
  25. San Mateo County Controller, 2025-2026 Tax Rate Book (Town of Hillsborough tax rate areas 006-002 through 006-009). The $72,700 example is calculated at the 1.1185% composite rate and excludes special charges.
  26. California State Board of Equalization, Publication 29, California Property Tax: An Overview, March 2025.
  27. Internal Revenue Service, Like-Kind Exchanges Under IRC Code Section 1031 (accessed October 2026).
  28. Client testimonials on jenngilson.com (accessed October 2026).
  29. Town of Hillsborough, Historic Review Application and residential design brochure.
  30. Jenn Gilson team page (accessed October 2026).
  31. Jenn Gilson listing page, 6 Cedar Lane, Woodside (accessed October 2026).
  32. Jenn Gilson's Zillow profile, accessed October 2026. Reviewers are not named.
  33. Video view figure provided by the Jenn Gilson team, October 2026.
  34. RealTrends public agent profile, Jenn Gilson, based on 2025 sales data.

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