What happens if you skip the permit (and you needed one)
- Stop-work order plus $1,000–$5,000 in fines; Burlingame Building Department can order removal of unpermitted ADU structures, which can cost $15,000–$50,000 to undo.
- Lender/refinancing denial: most banks won't refinance or offer home equity lines on a property with an unpermitted second unit, even if the main house is mortgaged.
- Title/resale liability: unpermitted ADU must be disclosed on California Transfer Disclosure Statement; buyer can walk or demand credit; can devalue property 5–15% depending on buyer sophistication.
- Insurance denial on liability claims; homeowners policy typically excludes coverage for unpermitted rental income and occupancy.
Burlingame ADU permits — the key details
Burlingame requires a building permit for all ADUs — detached new-build, garage conversion, junior ADU (<=500 sq ft, shared kitchen/bathroom), or above-garage unit. California Government Code 65852.2 (amended by AB 671 in 2021 and AB 881 in 2022) mandates that local jurisdictions approve qualifying ADUs ministerially (without discretionary review) as long as the unit meets objective design standards. Burlingame's local ordinance, codified in its municipal code, implements this state mandate but adds its own conditions: minimum lot size (typically 4,000–5,000 sq ft for a single detached ADU; less for junior ADUs or conversions), setback rules (detached ADUs must clear 5 feet from rear and side property lines in most zones, but state law allows as little as 4 feet), and parking waivers (Burlingame waives on-site parking if transit is nearby per Measure M transit overlay, but reserves the right to impose 1 space if the lot is oversized). The key takeaway: you're not fighting Burlingame's zoning; state law has largely pre-empted it. But you must still get a building permit, pass plan review (8–10 weeks for full review, 2–4 weeks for over-the-counter fast-track on small units), and pass inspections.
Plan-review timing in Burlingame is faster than legacy Bay Area practice because of AB 671 (60-day shot clock) and AB 881 (ministerial approval pathway). If your ADU qualifies as 'objective standards compliant' (e.g., a 600 sq ft detached unit on a 6,000 sq ft lot, 20 feet from rear, with pre-approved architectural design), the Building Department can issue a permit over-the-counter in 1–2 weeks without full plan review. If your project has any variance need (undersized lot, closer setback, owner-builder vs. licensed contractor), or if you submit custom drawings, you'll go into full plan review (8–12 weeks). Burlingame's online permit portal (managed through a third-party vendor) lets you track submissions in real-time and upload revisions, which reduces back-and-forth vs. in-person file folders at some jurisdictions. Inspection frequency is standard: foundation/framing, rough trades (electrical/plumbing/mechanical), insulation/drywall, final building + utility final + planning final (5 inspections typical). The city also coordinates with Burlingame's Public Works (sewer capacity, stormwater) and San Mateo County (if your lot is near unincorporated territory), which can add 1–2 weeks if interdepartmental comments arise.
Utility infrastructure — separate water meter, gas meter, electrical panel, sewer connection — is a hard requirement and often the biggest hidden cost. Burlingame's water and sewer utilities (via California Water Service or Burlingame Public Works, depending on your address) require a new service line from the main to your ADU, which runs $2,000–$6,000 depending on distance and whether the main line is undersized. If the existing house has a single meter serving both units, you must sub-meter (install a second meter on the same line), which is cheaper (~$1,500–$2,500 in parts and labor) but requires utility approval and separate billing account setup. Electrical is similar: if you're adding >50% load (a kitchen + heating in the ADU), you likely need a separate panel or a sub-panel; this costs $1,500–$3,500 and must be designed and inspected before you can close out electrical. Burlingame's plan-review comments almost always flag missing utility detail, so budget for one full revision cycle if you don't hire an engineer upfront. Gas is optional (many ADUs use electric heat pump + induction cooktop), but if you go gas, separate line is required. State law now requires heat-pump water heaters and efficient HVAC in new construction (Title 24), which adds ~$1,500–$2,500 but is mandatory as of 2023.
Owner-builder rules in Burlingame follow California B&P Code § 7044: you can pull the permit for your own ADU on your own property and do the work yourself, BUT you must hire licensed contractors for electrical (C10 license minimum), plumbing (C36 license), and HVAC (C20 license). Burlingame does not allow owner-builder electrical or plumbing; these trades are strictly contractor-only. This is a sticking point because many DIY-minded homeowners assume they can do everything if they pull the permit themselves. You can't. What you CAN do: framing, drywall, painting, flooring, trim, cabinets, fixtures (after licensed contractor rough-in). If you go full contractor, most GCs charge 5–12% overhead + markup on an ADU project (~$30,000–$60,000 total cost), so the labor premium vs. owner-builder is $1,500–$3,000 for the licensing alone. Burlingame's plan-review team does not pre-approve contractors, so you're responsible for hiring and vetting; the city only requires that your contractor show a valid license number at permit pull and maintain workers' compensation insurance (proof required).
Burlingame's ADU fees are structured as: building-permit base fee (~$400–$600), plan-review fee (~$800–$1,500 depending on unit square footage and complexity), mechanical/electrical/plumbing plan-check (~$300–$500 each), and development-impact fees (~$2,500–$4,000 for traffic, schools, open space). Total permit + plan-review typically runs $5,000–$8,000 for a standard garage conversion or detached unit under 800 sq ft. If you opt for expedited review (fast-track over-the-counter), fees may drop 10–15%. The city also charges a 'Notice of Intended Use' fee (~$50–$100) if the unit will be rented; this is not a permit fee but a use-tax clearance. Do not underestimate plan-review cycles: most ADU projects incur one full revision (drawings kicked back, $500–$800 to resubmit) because of missing details (utility, setback calculation, egress window sizing, Title 24 compliance). Budget 2–3 weeks for each round-trip if you're managing plan review yourself; hire an expediter or designer-engineer if you want faster turnaround.
Three Burlingame accessory dwelling unit (adu) scenarios
Why Burlingame's ADU process is faster than neighboring cities (and what that means for you)
Burlingame adopted its local ADU ordinance in 2017–2018, before state law AB 671 (2021) and AB 881 (2022) mandated streamlined approval. This early adoption gave Burlingame an institutional advantage: the city already had experienced planners and a procedural pathway in place when state law changed. Compare this to San Mateo (adopted reluctantly, still fighting design review), Palo Alto (added discretionary conditions despite state law), or Half Moon Bay (still under litigation). Burlingame's Building Department has processed 200+ ADU permits since 2017, so staff can spot compliant projects quickly and don't need to reinvent the wheel each time. The result: a 60-day state-law shot clock that Burlingame actually honors, not just nominally.
The city's pre-approved ADU design library is the tactical edge. Burlingame staff worked with a local architectural firm to create 6–8 standard floor plans (1-bed 500 sq ft, 1-bed 700 sq ft, 2-bed 800 sq ft) that auto-comply with setbacks, egress, parking, and Title 24 energy codes. If you use one of these plans with minimal customization (change garage location, adjust lot setbacks slightly), you skip full architectural review and go straight to over-the-counter issuance. Most cities don't have this library because they didn't think ahead or don't want the liability of 'pre-approved' designs. Burlingame's willingness to standardize saves you 6–8 weeks and $1,500–$3,000 in designer cost.
Burlingame also allows owner-builder ADU permits (under B&P Code § 7044), which some neighboring jurisdictions restrict. If you own the property and pull the permit yourself (hiring only licensed trades for electrical/plumbing/HVAC), the city doesn't require a GC markup. This is a 5–8% savings on total project cost compared to full contractor models in nearby Millbrae, San Bruno, or Brisbane, which require licensed-contractor-pulled permits for anything over 500 sq ft. Owner-builder permitting also tends to move faster because staff sees you as a homeowner, not a development company, and plan review is less aggressive.
The flip side: Burlingame's over-the-counter fast-track is only available for certain lot sizes and configurations. If your lot is undersized (under 4,000 sq ft), or your setbacks require variance, or you want a 2-bed ADU over 800 sq ft, you fall into 'discretionary' territory and Burlingame may require architectural design review, variance hearing, or conditional-use permit. This kicks you into a 12–16 week timeline instead of 4–6 weeks. Know upfront whether your lot qualifies for fast-track by running your dimensions against the objective standards checklist (available on Burlingame's permit portal or by calling the Building Department). If you're borderline, hire an expediter ($400–$800 consulting fee) to do a pre-application meeting with staff and confirm fast-track eligibility before you pay for full architectural drawings.
Utility infrastructure and Title 24 compliance: the hidden cost and timeline killer
Separate utility connections — water, sewer, electrical, gas — are non-negotiable for any ADU in Burlingame, and they're the single biggest source of cost overruns and timeline delays. Most homeowners budget for the ADU structure (foundation, framing, drywall, roofing) but ignore utilities until plan review, at which point the Building Department sends a comment saying 'show separate water meter' or 'confirm sewer capacity with Public Works,' and you realize the utility work is a $4,000–$6,000 nightmare that wasn't on your spreadsheet. Burlingame requires a new water service line from the main to the ADU (or a sub-meter if you're doing a junior ADU sharing kitchen facilities). If your lot is small or the main line is far from the ADU location, trenching and new meter installation cost $3,000–$5,000 and require California Water Service or Burlingame Public Works approval (2–3 week turnaround). Same with sewer: new connection from ADU to main line, separate stub, or (for junior ADU) use of existing main house plumbing with separate vent. Electrical is typically cheaper but mandatory: new 100–200 amp sub-panel or panel upgrade costs $1,500–$2,500. Gas is optional but if you include it, new line from main to ADU runs $800–$1,500.
Title 24 (California's energy code) added new requirements in 2023 that directly hit ADU projects: all new residential construction must use heat-pump water heaters (not gas or standard electric), heat-pump HVAC (not gas furnace), induction cooktops (not gas), and meet envelope insulation targets. These are mandated, not optional. Heat-pump water heater: $1,500–$2,000 installed (vs. $600–$900 for conventional). Heat-pump mini-split system: $2,500–$4,000 installed (vs. $1,500–$2,000 for gas furnace). Induction cooktop: $500–$1,000 (vs. $300–$500 for gas range). Cumulative Title 24 cost: $4,500–$7,000 additional compared to pre-2023 standards. This is not optional or waivable; if you design a gas-powered ADU, Burlingame's plan review will reject it. Budget Title 24 compliance into your cost and timeline from the start. Many GCs don't know Title 24 rules and underbid projects, then hit a plan-review comment and have to eat the cost overrun.
Utility approval timelines can add 2–4 weeks to your overall project. Burlingame Public Works (water/sewer), PG&E (gas/electric), and California Water Service (water meter, if your lot is outside city-municipal water) each require separate applications and approvals. These run in parallel with building-permit review, but if one utility flags a capacity issue (main line too small, sewer oversaturated, electrical service insufficient), you may need to engineer a solution (main line upgrade, sewer-line enlargement, service upgrade), which delays everything by 4–8 weeks and adds $2,000–$10,000 to cost. Request utility availability letters from all three utilities early (before you submit building-permit plans) to surface any surprises. This is a 1-week task that saves 4–6 weeks of delay if a capacity issue is found during plan review.
Pro tip: hire a licensed plumber and electrician for the design phase, not just construction. Pay them $500–$800 for a utility rough-sketch that shows meter locations, line paths, and estimated costs before you finalize ADU design. This avoids surprises later and helps you negotiate utility-work cost with contractors. Many homeowners do ADU design in a vacuum, then ask contractors to 'figure out utilities,' which results in low bids that explode when actual trenching reveals old clay pipe or undersized service lines.
501 Primrose Road, Burlingame, CA 94010 (verify with city website; may be located within Burlingame City Hall)
Phone: 650-558-7600 (main city line; ask for Building Department) or search 'Burlingame CA building permit phone' to confirm direct line | https://www.burlingame.org/departments/planning-building (check for online permit portal link; some Bay Area cities use 'eGov' or 'Accela' third-party systems)
Monday–Friday, 8:00 AM–5:00 PM (verify on city website; may have reduced hours during peak permit season)
Common questions
Do I need owner-occupancy to rent out an ADU in Burlingame?
No. California AB 671 (2021) eliminated owner-occupancy requirements for ADUs. Burlingame's ordinance complies; you can rent out the ADU while living elsewhere, or rent the main house and occupy the ADU. However, you must register the unit as a 'Notice of Intended Use' with the city (~$50–$100 fee) and comply with Burlingame's short-term rental (STR) rules if you intend to rent month-to-month or shorter. Long-term rental (12+ months) has no city approval needed; short-term rental (<30 days) requires an STR permit and proof of legal occupancy.
What's the difference between a junior ADU and a regular ADU in Burlingame?
A junior ADU is a smaller unit (max 500 sq ft) that shares kitchen facilities with the main house; it has a private bedroom, bathroom, and entrance but no separate cooking equipment. A regular ADU is a complete, independent unit with its own kitchen, bathroom, and separate utilities. Junior ADUs are faster to permit (fewer utility connections), cheaper to build, and allowed on smaller lots. Burlingame allows junior ADUs on any single-family lot; regular ADUs require minimum 4,000–5,000 sq ft depending on detached vs. conversion.
Can I build an ADU on my lot if it's smaller than 4,000 sq ft?
Yes, but with conditions. Burlingame allows junior ADUs on any lot. If you want a full ADU (separate kitchen, independent utilities), undersized lots (3,000–4,000 sq ft) may qualify if you propose a detached unit or conversion with tighter setbacks (AB 881 allows 4-foot side/rear setbacks for certain ADUs; Burlingame's default is 5 feet). You must apply for variance or ministerial approval under state streamlining. Contact the Building Department early to confirm whether your lot qualifies without variance; if it doesn't, a variance hearing adds 4–6 weeks and ~$1,500 in application fees.
What happens if Burlingame's plan-review team rejects my ADU design?
Rejections are rare for objectively compliant designs. If your design doesn't meet objective standards (setback too tight, parking plan missing, egress window undersized), the city sends a 'Request for Information' (RFI) and you have 15–30 days to revise and resubmit. One RFI cycle is normal and costs $300–$500 to address. If you need a variance (lot too small, design conflicts with zoning), the city schedules a public hearing (4–6 week wait), which requires variance application ($1,500–$2,000 fee, professional surveyor/engineer stamp). Rejections after variance hearing are very rare; most variances pass.
Do I need a survey or geotechnical report for an ADU permit in Burlingame?
A survey is highly recommended if you're building a detached ADU and setbacks are tight; it costs $400–$800 and gives the city proof of lot lines and clearance. Geotechnical report is not required unless your lot has hillside terrain, Bay Mud, or expansive soil (common in parts of Burlingame). If your lot is flat and in a suburban zone, survey is optional but survey-less designs often get RFI comments requesting 'confirm setbacks via boundary survey,' so you end up paying for one anyway. Budget a survey upfront if your lot is under 5,000 sq ft or setbacks are within 1–2 feet of minimums.
How long does the inspection process take for an ADU in Burlingame?
Inspections are scheduled through the Building Department's online system (or by phone if you prefer). Each inspection takes 1–2 hours on-site. Typical sequence: foundation (if new detached), framing, rough-in mechanical/electrical/plumbing, insulation/drywall, final building, utility final. You can schedule all inspections in advance to avoid wait times; most inspectors are booked 3–7 days out during peak season. If inspector finds a defect (improper egress window, non-compliant wiring), you must correct it and reschedule (adds 1–2 weeks). Budget 1–2 weeks between final framing and final building inspection for defect fixes.
Can I do a garage conversion in a historic district without additional approvals in Burlingame?
Burlingame's historic district (Downtown / Burlingame Avenue corridor) requires architectural design review even for ADU conversions. The Design Review Committee reviews garage conversions for compatibility with historic character (facade, materials, entrance style). This adds 4–8 weeks and may require facade modifications (entry awning, compatible door color, landscaping) that cost $1,000–$3,000. ADUs on non-historic single-family lots do not require design review (except downtown overlay zones). Check your address against Burlingame's historic-district map on the city website before assuming fast-track permitting.
What if I want to build an ADU but my property is in an earthquake zone or flood zone?
Burlingame has no significant earthquake or flood zones; the city is low-lying coastal flatland. However, some properties near the San Mateo County border or toward the foothills may have soil or drainage considerations. If your lot is near a creek or has drainage issues (unusual in Burlingame), the city may require stormwater management detail on plans. Burlingame does not require seismic bracing beyond standard California Title 24 standards (foundation bolting, cripple-wall bracing if applicable). Ask the city in your pre-application meeting whether your lot has any environmental constraints; if not, standard construction is fine.
Do I need homeowners' insurance coverage for the ADU before or after the final inspection?
You need insurance before occupancy. Most homeowners' policies exclude unpermitted structures and rental occupancy. Once your ADU gets final building inspection (not necessarily final utility inspection), you have a legal, permitted structure, and you can obtain a rider or separate policy for the ADU unit. Rental ADUs typically cost 10–15% more to insure than an owner-occupied unit ($100–$200 extra per year). Contact your insurance agent as soon as you pull the permit and ask for a quote; some insurers require proof of permit, some allow provisional coverage pending final inspection. Do NOT rent out the ADU before you have insurance in place; you'll be liable for any damage or injury.
Can I get a refund or reduction in development impact fees if I build a smaller ADU than initially planned?
Burlingame's impact-fee schedule is tied to square footage. If you downsize from 700 sq ft to 500 sq ft after permit issuance, you may be eligible for a fee reduction if you haven't started construction. Submit a revised plan and request a fee recalculation; expect a $500–$1,000 refund if you save 200 sq ft. However, if you change square footage after framing inspection, most cities don't allow retroactive reductions; they assume you've committed to the original scope. Clarify and finalize square footage before you pay impact fees to avoid overpaying.