What happens if you skip the permit (and you needed one)
- Stop-work orders cost $300–$1,000 in fines and force system shutdown until unpermitted work is remedied; Danville code enforcement conducts neighborhood complaints within 2–3 weeks.
- Your homeowner's insurance may deny a claim (roof damage, fire, electrical fault) if the solar system was not permitted; underwriters routinely request permit cards during claims processing.
- At sale, California's Transfer Disclosure Statement (TDS) requires you to disclose unpermitted solar; buyer's lender may refuse to finance the property, killing the sale.
- A lien can attach to the property for unpermitted work if the contractor disputes payment; Danville's Recorder documents unpermitted solar claims as mechanic's liens within 90 days.
Danville solar panel permits — the key details
California's Title 24 (2022 standards) and NEC Article 690 form the legal floor for Danville solar. The city adopted these codes wholesale in 2022; they apply to every residential and commercial installation. The core rule: all grid-tied systems must have a building permit (for roof structural evaluation, fire setbacks, and mounting), an electrical permit (for NEC 690 rapid-shutdown compliance, inverter labeling, conduit sizing, and bonding), and written evidence of utility interconnection (PG&E approval letter or similar). Off-grid systems are exempt from the utility interconnection requirement but still require both building and electrical permits if they include battery storage over 5 kWh; the Fire Marshal must review the battery enclosure, disconnect switch, and emergency protocols. Danville's online permit portal (accessible via the city website) accepts PDF submittals, stamp-dated structural reports, and utility pre-approval letters; you upload these together. The Building Department's standard practice is to issue a 'Notice of Intent to Approve' within 5–10 business days if structural and electrical details are complete. Battery storage systems (ESS) over 20 kWh require an additional Fire Marshal plan check; expect 3–4 weeks total for ESS projects.
Roof structural evaluation is the first gating factor. If your roof framing is post-1995 (common in Danville's newer subdivisions), your PE or structural engineer can often certify the roof as compliant without a full retrofit; this takes 3–5 days and costs $300–$800. If your roof is older wood-frame construction (pre-1980s) or has known conditions (rot, inadequate bracing), the engineer may require sistering of rafters, added knee-braces, or bolting of the top plate to the house framing; costs for retrofit range $2,000–$8,000. Danville's Building Department requires a sealed structural report signed by a California-licensed PE or SE (Structural Engineer); stamped PDF is acceptable in the online portal. Solar panel systems are typically 3–5 lbs per square foot; your roof must be evaluated for dead load (panel weight), live load (wind and snow), and seismic loads per ASCE 7. The city does not waive structural review for 'small' systems; the permit form requires a box checked: 'Structural evaluation completed by licensed PE' — no check, no permit.
Electrical permit and NEC 690 compliance is the second critical gate. Your electrician must submit a one-line diagram showing the inverter, DC disconnect, AC disconnect, conduit routing, overcurrent protection (breaker or fused disconnect), and bonding details. NEC 690.12 (rapid-shutdown) is Danville's focus: the system must have a rapid-shutdown initiation switch (typically wall-mounted, labeled, within 10 feet of the inverter) that de-energizes the PV array and reduces voltage to safe levels within 10 seconds. If you have microinverters or power optimizers (common for partial-shade roofs), each must have its own control pathway to the rapid-shutdown switch; this adds cost ($500–$1,200) and complexity. The electrical contractor must also verify that the existing home electrical panel has adequate capacity to accept the solar output; if the main breaker is 100 amps and the solar is 7 kW (30 amps), you may need a sub-panel or panel upgrade ($1,500–$4,000 additional). Danville's electrical plan check typically takes 5–7 business days; if there are deficiencies in the diagram, the inspector will issue a 'Request for Information' (RFI), and you have 5 business days to resubmit.
Utility interconnection (PG&E) must be initiated BEFORE the city will issue your building permit. This is a hard rule in Danville: the online portal requires you to upload a PG&E pre-application or 'Interconnection Request' letter dated within the last 60 days. If you don't have this, the city will place your permit 'on hold' (not rejected, but inactive) until you obtain it. PG&E's process is separate from Danville's; you submit your one-line diagram, service address, and system size directly to PG&E via their online portal (www.pge.com/interconnection). PG&E typically issues a pre-application acknowledgment within 10 business days and a full interconnection agreement within 2–4 weeks. If your system is under 10 kW (residential standard), PG&E will usually issue a simplified 'Level 1' agreement with no utility upgrades required; larger systems or three-phase service may require 'Level 2' study (4–8 weeks, possible utility cost-share). Danville does not allow the city permit to be finalized until PG&E approves the interconnection agreement; this is required by California Public Utilities Code § 769 and enforced by Danville's Building Official.
Timeline and fees in Danville are governed by AB 2188 (expedited review) and the city's current fee schedule. For qualifying residential systems (under 10 kW, roof-mounted, no battery), the Building Department aims for same-day or next-day issuance if structural and electrical submittals are complete at intake. However, if the structural engineer identifies needed roof reinforcement or the electrical contractor's diagram is missing rapid-shutdown details, expect a 5–7 day RFI and resubmittal cycle. The building permit fee is typically $200–$400 (roughly 0.5–1% of system valuation, depending on size). The electrical permit is $150–$250 (separate fee). If a roof retrofit is required, you will pay the engineer $300–$800 and contractor costs $2,000–$8,000. Battery storage adds a Fire Marshal application fee of $50–$150 and 2–3 weeks of additional plan check. Total permit-to-approval timeline is 1–3 weeks for grid-tied systems without battery, and 4–6 weeks with battery. Danville accepts digital submissions only; no paper filing is available. Inspections are scheduled online via the portal: rough electrical (before panels are mounted), structural/mounting (after rails and flashing are installed), and final electrical (after inverter is energized). PG&E's inspector will schedule a separate 'witness' inspection to activate net metering; this is typically same-day or next-day after the city's final.
Three Danville solar panel system scenarios
Danville's streamlined permit portal and AB 2188 expedited review
Danville adopted California's AB 2188 (expedited solar review) in 2023. The law requires local agencies to approve or deny residential solar permits within 5 business days if the application is 'complete' (meaning structural evaluation + electrical one-line + utility interconnection letter are all present). In practice, Danville's Building Department issues a 'Notice of Intent to Approve' within 3–5 days for systems under 10 kW if submittals are thorough. The city's online permit portal (accessible via the city website) is the sole filing method; walk-in and mail submission are no longer available. You create an account, upload PDF files (structural report, one-line diagram, PG&E pre-app letter, site photos), and pay the permit fee by credit card. The system auto-assigns the application to an inspector and sends a status email within 24 hours. If there are deficiencies (e.g., missing rapid-shutdown details on the diagram), the inspector sends an RFI (Request for Information) via email, and you have 5 business days to resubmit the corrected page. Resubmittals do not reset the 5-day clock under AB 2188; the city must issue a final decision within 10 days of the original submission. This is faster than traditional permitting but requires you to be organized: have your PE's report, electrician's one-line diagram, AND PG&E's pre-app letter ready before you upload. Many homeowners miss the PG&E step and have their permit held until they obtain the utility letter; this adds 2–3 weeks.
Danville's roof structural requirements and retrofit costs for older homes
Danville's building stock is mixed: newer subdivisions (1990s–2010s) have engineered roof framing that typically passes solar loading without retrofit; older neighborhoods have wood-frame homes from the 1960s–1980s with minimal bracing and no hurricane tie-downs. The difference in cost is dramatic. A 1995 roof with engineered trusses or sistered rafters can accept a 5 lb/sq ft solar load with a 2-page PE letter and no physical work (cost: $500–$800). A 1970s roof with 2x6 rafters, spaced 24 inches, and no knee-braces or ridge ties often fails the seismic and wind checks and requires full sistering (add a second 2x6 joist next to each rafter), lag-bolting of the top plate, and new L-brackets at the ridge. This retrofit costs $6,000–$10,000 depending on roof pitch and complexity. For a 6 kW system ($12,000–$15,000), a $8,000 roof retrofit can be a deal-breaker. Danville's Building Department does not waive structural review for 'small' systems (under 5 kW); the code requires a sealed PE report for ALL systems. If your home is pre-1995, budget for a structural assessment ($300–$600) and be prepared for retrofit costs before you commit to solar. The city does allow you to apply for the building permit conditional on completing the retrofit; once the structural work is inspected and passes, the permit is finalized. This sequence helps: you know the retrofit cost before you commit to the full system installation.
510 La Gonda Way, Danville, CA 94526
Phone: (925) 314-3300 (main line; ask for solar/electrical permits) | https://www.danville.ca.us/government/permits-and-planning
Monday–Friday, 8:00 AM–5:00 PM (closed weekends and city holidays)
Common questions
Do I need a permit if I'm just replacing my existing solar panels with new ones?
Yes. Even a replacement system requires a building permit (to re-evaluate roof loading under current code) and an electrical permit (new inverter, wiring, rapid-shutdown compliance). The structural evaluation is usually simpler if the new system is the same wattage and weight as the old one, but Danville's Building Department will still require a sealed report confirming this. Total cost: $300–$500 in permits, 1–2 weeks timeline.
Can I pull the permit myself as an owner-builder, or do I have to hire an electrician?
Danville and California law require a California-licensed electrician (not owner-builder) to sign off on the electrical permit for solar. This is enforced by the Contractors State License Board and the city's electrical inspector. You can hire a general contractor to manage the project, but the electrician must be licensed. Owner-builder exemptions (California B&P Code § 7044) do not apply to electrical work on your own home. Expect to pay the electrician $1,500–$3,000 in labor and plan-check time on top of their system design and installation.
What if I buy a pre-designed system online (SunRun, Vivint, etc.) and just want to install it?
Third-party companies like SunRun and Vivint typically include permit coordination as part of their service agreement; they hire local electricians and structural engineers on your behalf and manage the filing. However, you (the homeowner) are still legally responsible for the permit and inspections. If the contractor doesn't pull the permit and the system is found unpermitted, you face fines and forced removal. Always verify that your solar company has confirmed permits with Danville before installation begins. Ask for a copy of the permit number and receipt; do not proceed without it.
How long does it take for Danville to issue the permit after I submit?
For complete submittals (structural report + electrical one-line + PG&E pre-app letter), Danville typically issues a 'Notice of Intent to Approve' within 3–5 business days under AB 2188. If there are deficiencies (missing rapid-shutdown details, incomplete one-line), expect a 5–7 day RFI and resubmittal cycle, extending the total to 10–14 days. Battery storage systems take 4–6 weeks due to Fire Marshal review. Danville's online portal updates your status within 24 hours of submission.
Do I need separate permits for a roof repair or replacement if I'm adding solar?
If your roof is damaged and you're adding solar at the same time, you will need TWO separate permits: one for roof work (building permit, issued by the Building Department) and one for solar (building + electrical permits). The roof permit is separate and typically takes 1–2 weeks. Coordinate with your contractor so that the solar mounting is designed AFTER the roof repair is complete and inspected; otherwise, the structural PE cannot evaluate the new roof's capacity. If your roof is in good condition, no separate roof permit is required.
What is 'rapid-shutdown' and why does Danville require it?
Rapid-shutdown (NEC 690.12) is a safety feature that de-energizes the PV array and reduces voltage to below 80 V within 10 seconds. This protects firefighters and first responders who may be working on or near the roof during an emergency (fire, earthquake, etc.). Modern inverters have rapid-shutdown built-in, but you must install a wall-mounted switch (labeled 'PV Rapid Shutdown') within 10 feet of the main electrical panel. Some systems use microinverters or power optimizers on each panel, which achieves the same result. Danville's electrical inspector will verify rapid-shutdown functionality during the final inspection; if it's missing or non-functional, the permit will not be finalized. There is no cost to include rapid-shutdown if you use a standard string inverter, but microinverters add $500–$1,200.
Can I apply for the permit before I hire a contractor?
Partially. You can initiate the structural evaluation and request the PG&E pre-application letter on your own; these are public documents and don't require a licensed contractor's signature. However, the electrical one-line diagram MUST be signed by a California-licensed electrician, and the mounting installation MUST be done by a contractor or licensed solar company. So: you can do the early-stage planning and get the structural report, but you need to hire the electrician and contractor before you can submit the full permit package.
What happens if I install solar without a permit and then try to sell my house?
California's Transfer Disclosure Statement (TDS) requires you to disclose any unpermitted work, including solar. If you didn't disclose it and the buyer's home inspector finds it, the buyer can sue you for fraud or back out of the sale. If you disclose it, the buyer may demand that you remove the system or retroactively permit it. Retroactive permits in Danville are rare and expensive; the city may require a full structural retrofit and reinspection, costing $5,000–$15,000. Your lender (if you refinance) will also require a permit before releasing funds. Unpermitted solar is a significant liability at resale; do not skip the permit.
If I have a battery system, do I need approval from PG&E?
No. PG&E does not regulate on-property battery storage under 50 kWh; this is a local Fire Marshal issue under the California Fire Code (IFC 1206.2). However, if your battery system includes grid-export capability (you sell power back to the grid), PG&E's interconnection rules apply. Most residential battery systems are designed for load-shifting (store solar during the day, use it at night or during PSPS blackouts) and do not export to the grid; in this case, PG&E has no authority. Always clarify with your electrician whether your system exports power.
How much does the total solar project cost in Danville, including permits and installation?
A typical 6 kW grid-tied system (no battery) on a newer home costs $12,000–$15,000 installed, plus $400–$600 in permits and structural evaluation. If your roof requires retrofit, add $6,000–$10,000. A 6 kW system with 10 kWh battery and hybrid inverter costs $20,000–$28,000 installed, plus $600–$800 in permits. Federal tax credit (30% ITC through 2032) and California SGIP (rebate for low-income or fire-risk areas) may reduce out-of-pocket costs. After federal tax credit, typical net cost is $8,500–$15,000 for grid-tied, and $14,000–$20,000 for grid-tied-with-battery. Permits are typically 1–2% of the total system cost; the biggest cost variability comes from roof retrofit and electrical sub-panel upgrades.