Santa Rosa has spent the years since 2017 rebuilding thousands of homes, and the city's builders, inspectors and suppliers know the process well. For an investor, that history shapes every project: fire-resistant building standards, insurance questions, high labor costs and a state law framework that allows more units per lot than ever.
In short: LendingStreet funds ground-up construction loans for 1-8 unit investor projects in Santa Rosa and across Sonoma County, including spec homes, rebuilds on vacant fire lots, homes with ADUs, SB 9 duplexes and small 5-8 unit buildings. Loans are sized on loan-to-cost with terms set per project, and funds are released through a draw schedule after inspections. Plans, permits, a detailed budget and builder experience matter.
Some vacant lots remain in neighborhoods burned in the 2017 Tubbs Fire and the 2020 Glass Fire, including parts of Fountaingrove and the Skyhawk area. Infill lots across the city are being used for homes with detached ADUs, and California's SB 9 allows duplexes and lot splits on many single-family parcels, subject to local standards.
Builders also work in Windsor, Rohnert Park and Petaluma, each with its own permit office and fee schedule. Unincorporated Sonoma County projects go through the county's permit department.
| Project type | Where it is common | What to plan for |
|---|---|---|
| Rebuild on a vacant fire lot | Fountaingrove, Skyhawk, scattered lots | WUI standards, insurance, utilities already in place |
| Spec home with detached ADU | Infill lots citywide | ADU standards; two exit options |
| SB 9 duplex or lot split | Eligible single-family lots | Eligibility rules, local objective standards |
| Small 5-8 unit building | Multifamily-zoned infill | Longer review; commercial-grade code items |
Much of the hillside and edge areas of Santa Rosa are mapped as fire hazard severity zones, and new homes there must meet California's wildland-urban interface building standards: ignition-resistant siding, Class A roofing, ember-resistant vents, tempered glazing and other requirements. These add cost, but they also help with insurance and resale.
Even outside mapped zones, building with fire-resistant materials can make the finished home easier to insure. Include those upgrades in the budget from the start.
North Bay winters bring heavy rain, and grading and foundation work during the wet season usually require erosion control and can be delayed by storms. Many builders aim to have foundations in and the structure dried in before the rainy season begins. A project that starts late in the year may lose weeks to weather.
Sloped lots in the eastern hills often need retaining walls, drainage and engineered foundations, which add cost and inspection steps. Flat valley-floor lots are simpler but may have their own soils or drainage questions, so a soils report is worth the money on almost any Santa Rosa lot.
This example is illustrative and not a quote. A builder buys a vacant former fire lot for $225,000 and plans a single-family home with a detached ADU. Hard costs are $790,000, fire-resistant exterior upgrades add $30,000, soft costs including plans, permits, impact fees and utility connections are $115,000, and the contingency is $45,000. Total project cost is $1,205,000.
At 80% loan-to-cost, the construction loan is $964,000 and the builder's equity is $241,000. Funds are released in draws after inspections at each stage.
If the finished property sells for $1,475,000, the projected profit after selling costs and estimated interest is about $125,829. If the builder holds it, the house and ADU lease for about $6,100 combined, but with taxes reassessed on the new construction, the largest DSCR loan at 1.0x is about $648,000. Holding would require paying down about $316,000 at refinance.
| Sources and uses | Amount |
|---|---|
| Lot (former fire lot, land credit) | $225,000 |
| Hard costs: house and detached ADU | $790,000 |
| Fire-resistant exterior upgrades | $30,000 |
| Soft costs: plans, engineering, permits, impact and utility fees | $115,000 |
| Contingency | $45,000 |
| Total project cost | $1,205,000 |
| Construction loan at 80% loan-to-cost | $964,000 |
| Builder equity, including land | $241,000 |
The same project produces very different results depending on the exit. Selling repays the construction loan. Holding in Santa Rosa usually requires substantial equity, because new construction is assessed at current value and rents are moderate relative to building costs.
One exception is worth knowing. California has rules that can let an owner who rebuilds after a disaster keep the prior assessed value for a comparable replacement, with only added square footage assessed at current value. A buyer who purchases a vacant fire lot generally starts with a new assessed value instead. If you owned the property before the fire, confirm your status with the Sonoma County Assessor, because a lower tax bill can change the hold math considerably.
Other paths include selling the finished house and ADU as a package to an investor buyer, or dividing the lot under SB 9 where eligible and selling one home while holding the other. Each structure carries its own permit, valuation and lending questions, so decide early.
| Exit | Sell on completion | Hold as a rental |
|---|---|---|
| Value or rent | $1,475,000 value | $6,100 a month (house plus ADU) |
| Main costs | $88,500 selling costs, about $55,671 interest | $1,789 a month taxes and insurance |
| Result | About $125,829 projected profit | Largest DSCR loan at 1.0x about $648,000 |
| What it means | Repays the construction loan | About $316,000 must be paid down at refinance |
Santa Rosa charges development impact fees and utility connection fees on new homes, and some fees are reduced for smaller ADUs under state law. Fire lots may already have utility stubs, which can save money, but confirm their condition. Include survey, soils report, engineering, plan review and permit fees in your soft cost budget.
California's energy code also applies to new homes, and local rules on building electrification have been changing across the state. Ask the city which energy requirements apply to your permit application date, since they affect equipment choices and cost.
Projects without plans or permits, or a borrower with no build track record and no experienced general contractor, usually do not qualify.
Draw requests follow the schedule set at closing; an inspector confirms each stage before funds are released. Builder's risk insurance is required, and in Sonoma County it can take time to place, so start early. Use our construction draw schedule calculator to map your budget, then send your plans and budget. Call (877) 298-1001 or use the form below.
Yes. We fund 1-8 unit investor projects in Santa Rosa and Sonoma County, sized on loan-to-cost with terms set per project.
Yes, with approved plans and permits. Expect to meet wildland-urban interface building standards in mapped fire hazard zones.
Many single-family lots are eligible under SB 9, subject to state rules and local objective standards. Confirm eligibility with the city.
Funds are released in stages after inspections confirm completed work.
It affects the schedule. Plan foundation and grading work for drier months where possible and budget for weather delays.
Yes, into a DSCR loan once the property is leased, though the loan amount may be lower than the construction loan.
Those are commercial projects. See our multifamily lending.
New construction is generally assessed at current value. Owners rebuilding after a disaster may keep the prior assessed value for a comparable replacement under California rules; confirm with the Sonoma County Assessor.
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