What happens if you skip the permit (and you needed one)
- Stop-work orders and fines: Collin County building inspectors can issue a stop-work order (typically $500–$1,500 penalty) plus require removal of unpermitted work; Oncor may also disconnect your system if they discover an unregistered interconnect.
- Insurance denial and resale hit: Your homeowner's insurance may deny claims related to unpermitted solar work, and Texas Residential Tenancy Code disclosure laws require you to reveal permit violations to buyers, often killing the sale or triggering $10,000–$50,000 price reductions.
- Lender and refinance block: Banks and mortgage lenders routinely discover unpermitted solar during appraisals or refinancing; some will withhold closing until permits are retroactively pulled and inspected, adding $1,000–$3,000 in expedited-review fees.
- Utility interconnect denial: Oncor may refuse to activate net metering or interconnect credits for unpermitted systems, leaving you with a non-functional array and no legal path to recover the $15,000–$40,000 system cost.
Murphy solar permits — the key details
Murphy enforces the 2015 International Building Code (IBC) and National Electrical Code (NEC) Article 690 (Photovoltaic Power Production Sources) without exemptions. This means all grid-tied solar systems — from a 3 kW starter array to a 10 kW full-roof install — require both building and electrical permits. The building permit covers structural adequacy of your roof, mounting design, and compliance with IBC 1510 (Rooftop Solar Panels), which mandates that your roof can structurally support the added load (typically 3–4 pounds per square foot for residential systems). The electrical permit covers wiring, inverter labeling, rapid-shutdown compliance (NEC 690.12 — a safety device that de-energizes all wiring on the roof within 10 seconds of grid loss), conduit fill, grounding, and disconnect locations. Murphy does not offer a blanket exemption for small systems, owner-built arrays, or battery-free installations. NEC 705 (Interconnected Power Production Systems) also applies if your system connects to the grid, requiring a utility interconnection agreement.
Your first step before submitting to Murphy Building Department is completing Oncor Electric Delivery's utility interconnection application. Oncor serves most of Murphy and requires you to submit their 'Distributed Generation Application' (Form DG-1 or equivalent) to their interconnections team. This application typically takes 2–4 weeks for Oncor to review; they check whether your inverter meets IEEE 1547 anti-islanding standards, whether your switchgear and disconnect placements meet NFPA 70 (NEC) standards, and whether the utility grid can safely accept the power you're exporting. Do not file your electrical permit with Murphy until Oncor has approved your application or at least confirmed no objections — if you do, Murphy's electrical inspector may reject your rough inspection and require you to resubmit pending utility sign-off. Practically, start with Oncor 4–6 weeks before you want to turn on your system.
The building permit focuses on roof attachment, wind loading, and structural reserves. Murphy's inspectors will require a roof load calculation (usually provided by your installer or engineer) showing that your current roof structure can safely support the PV array, combiner boxes, and conduit at your specific roofing material and slope. If your roof is older (15+ years) or has been repaired, the inspector may require a structural engineer's letter of adequacy. For metal roofing or standing-seam, you'll need documentation of flashing compatibility and attachment method (L-foot vs clamp vs rail-less). Snow load and wind load are less critical in Murphy (Collin County lies in the 2A-3A climate zone with modest snow, but 100+ mph wind-resistant design is now standard for the Dallas area). Roof penetrations must use roof boots or flashing rated for your shingles. The building inspector will walk the roof during rough inspection (typically 1–2 weeks after permit issuance) and again at final inspection after the array is mounted and conduit run.
The electrical permit is where most solar rejections happen. Murphy's electrical inspector (or the permit department's contracted reviewer) will scrutinize your one-line diagram, showing string configuration, inverter model, breaker/disconnect locations, and rapid-shutdown device. NEC 690.12 now mandates that any DC wiring between modules and inverter be de-energized within 10 seconds of grid loss — this typically means a relay-based rapid-shutdown device mounted on or near the array (SolarEdge, Enphase, or SMA Sunny Boy with integrated shutdown all meet this; string inverters alone do not). Your diagram must also show proper AC and DC breaker sizing (per NEC Tables 310 and 240), conduit fill (typically PVC Schedule 40 for exposed exterior runs), and grounding electrode system connections. Battery storage (if included) adds NEC Article 705.30 requirements for energy-storage systems and may trigger Fire Marshal review if capacity exceeds 20 kWh. The electrical permit fee is separate from building and typically runs $150–$300 in Murphy; combined building + electrical for a 5 kW system averages $300–$800.
Timeline and inspections: Permit issuance (after AHJ review) typically takes 1–2 weeks in Murphy, though the city does not advertise expedited review. Once issued, you have roughly 6 months to begin work before the permit expires. After your installer completes mounting and rough wiring (before connecting to the grid), you'll schedule a building rough inspection and an electrical rough inspection — these are often done the same day by separate inspectors. The building inspector checks roof attachment, flashing, conduit routing, and clearances (typically 3 feet from roof edges, vents, and skylights per IBC 1510.5). The electrical inspector verifies rapid-shutdown functionality, breaker ratings, grounding continuity, and polarity. Once both rough inspections pass, you notify Oncor that you're ready for their witness inspection; Oncor will send a technician to verify the disconnect location, interconnect meter reading, and that the system is configured to their standards (typically within 1–2 weeks). Only after Oncor approves and activates your net-metering agreement can you energize the system. Final inspection with Murphy follows, and they issue a Certificate of Occupancy / final approval. Total timeline from permit application to energized system is typically 3–6 weeks in Murphy, assuming no rejections and Oncor has no backlog.
Three Murphy solar panel system scenarios
Oncor Interconnection and Net Metering in Murphy
Oncor Electric Delivery is the transmission and distribution provider for most of Murphy and northern Dallas County. Unlike solar-friendly states with statewide net metering (California, New York), Texas leaves net metering rates and rules to individual utilities; Oncor has historically offered a 1-to-1 net metering credit under their NODIS (Non-Delivered Service) tariff, meaning every kWh you export to the grid offsets a kWh you consume at your retail rate (roughly $0.12–$0.15 per kWh in the Dallas area as of 2024). However, Oncor requires a completed Distributed Generation (DG) Application before you can interconnect; this application must be approved by their Interconnections Engineering department before Murphy's Building Department will issue your electrical permit. The process typically takes 2–4 weeks. Oncor reviews three things: (1) Does your inverter meet IEEE 1547 anti-islanding standards? (2) Are your disconnects and switchgear placed where Oncor technicians can safely isolate the system? (3) Will exporting your power overload the local feeder or transformer? For residential systems under 10 kW, Oncor almost never objects to the first two; the third is rarely an issue in Murphy's suburban neighborhoods. However, if you live in an area with heavy solar adoption or on a weak feeder, Oncor may request a detailed power-flow study or require you to upgrade the local transformer, which would be your cost ($5,000–$15,000). This is rare, but it's a real risk. Once approved, Oncor installs a 'smart meter' (usually no charge) and enables net metering in your account. The meter automatically tracks imports and exports on an hourly basis, and at the end of each billing cycle, if you've exported more power than you've consumed, Oncor carries that surplus forward as a credit (not a cash payment, a bill reduction). This credit never expires as long as you remain a customer, making net metering highly valuable for oversized systems or low-consumption homes.
The timeline to live power is bottlenecked by Oncor's inspection, not Murphy's. Even if Murphy issues your electrical permit in 1 week and your installer completes the rough wiring in 2 weeks, you cannot energize (connect to the grid) until Oncor has sent a technician to witness your AC disconnect, verify the system de-energizes on grid loss, and manually test the net-metering meter. This witness inspection typically takes 1–2 weeks to schedule after you call Oncor ready. During this inspection, the Oncor tech will also verify that your disconnect switch is clearly labeled 'PV Disconnecting Means' per NEC 690.53, that it's accessible, and that the inverter is not energizing the house without grid power (anti-islanding check). After Oncor's tech approves, they activate net metering in your account (sometimes immediately, sometimes 3–5 business days). Only then can you flip the AC breaker and export to the grid. If Oncor's inspection fails (e.g., you forgot to install the rapid-shutdown device, or the DC disconnect is inaccessible), you'll be asked to fix it and re-schedule, adding 1–2 more weeks. Pro tip: Confirm with Oncor at least 1 week before scheduling your Murphy rough inspection that your system meets their checklist — this prevents a common trap where the building inspector passes, but Oncor's tech rejects on the same day, forcing you to pull a Correction Permit and re-inspect.
Roof Structural Adequacy and Ice Load Concerns in North Texas
Murphy's location in Collin County (north Dallas metro) sits in IECC Climate Zone 3A, with a 50-year wind speed of 95 mph and occasional winter ice storms (though ice loads are generally lighter than northern states). The 2015 IBC (which Murphy enforces) requires that roof structures carry the combined dead load (shingles, sheathing, rafters) plus live load (maintenance, wind, snow/ice) plus the PV system load. A typical residential solar array adds 3–4 pounds per square foot (the panels themselves are ~2.5 lbs/sq ft; the racking adds 0.5–1.5 lbs/sq ft). Most modern roofs built to code since 2000 can support this without modification, but older homes (pre-1990) or roofs that have been patched, reroofed, or damaged may have less capacity. Murphy's building inspectors routinely ask for a roof load calculation from installers; this is a simple spreadsheet or engineer's analysis that sums the dead + live + PV loads and confirms the roof joists (or trusses) are not overstressed per the IBC Table R802.5.1 (lumber bending moment limits). If the roof is marginal, you have two options: (1) Install fewer panels (reduce load to 2–3 kW), or (2) Reinforce the roof with additional collar ties or sister joists, adding $1,000–$3,000 in structural work. Ice load in Murphy is typically only a concern during rare winter events (1–2 times per year, usually under 1 inch); the IBC accounts for this in the general live-load assumptions (20 lbs/sq ft for roofs in Dallas area), which your installer's load calc will include. Wind load is more critical: a 95 mph design wind creates suction on the roof (uplift), and the PV system adds a large flat surface to catch wind. Modern array racking is designed to resist this, but the attachment points (where L-foot mounts bolt to the roof trusses) must be robust. Murphy's inspector will verify that penetrations are sealed with roof boots (not silicone caulk alone) and that bolts are into solid wood (not sheathing or insulation).
A common rejection in Murphy is missing roof condition documentation. If your roof is original or over 10 years old, the building inspector may require a roof certification from a roofing contractor stating that the roof is structurally sound and has at least 5 years of remaining life before replacement. This prevents a situation where homeowners install $20,000 in solar, then have to tear it all down 2 years later to replace a failing roof. The certification typically costs $200–$400 and takes 1 week to obtain. For new or recently reroofed homes (within 5 years), inspectors usually waive this. Also note: If you're on a metal roof, standing seam, or other non-shingle material, the racking compatibility becomes critical. Some standing-seam roofs use proprietary clamp systems that the inspector will want to see pre-approved by the roof manufacturer or backed by an engineer's letter. Don't assume your racking is compatible — confirm with the roof type before you buy the array.
Murphy City Hall, 205 W Martin Street, Murphy, TX 75094
Phone: (972) 468-7225 | https://www.murphytexas.org/government/departments/planning-and-zoning/building-permits
Monday–Friday, 8:00 AM – 5:00 PM
Common questions
Do I need a permit if I install a small 1–2 kW DIY solar kit that doesn't connect to the grid?
Yes, you still need permits. Even off-grid systems require an electrical permit in Murphy to verify safe DC wiring, grounding, and disconnect placement per NEC Article 690. Off-grid systems over a certain capacity may also require a battery storage permit (typically kicks in at 20 kWh). There is no blanket exemption for small DIY kits. However, off-grid systems do not require Oncor approval, which saves 2–3 weeks. If you're building a backup battery system for grid-outage resilience only (not exporting to the grid), confirm with Murphy's electrical inspector that your system qualifies as off-grid; if you ever connect to Oncor later, you'll need to re-permit as grid-tied.
How long does the Oncor interconnection approval usually take?
Typically 2–4 weeks for standard residential systems under 10 kW. Oncor's Interconnections Engineering team reviews your DG-1 application, inverter specifications, and system single-line diagram. If they have no questions and your feeder has capacity, approval is quick (15–20 days). If the application is incomplete or they request additional information, it can stretch to 4–6 weeks. Do not wait until after your Murphy building permit is issued to apply to Oncor — apply simultaneously (or Oncor first) to overlap the timelines and avoid delays.
What is 'rapid-shutdown' and why does the inspector care?
Rapid-shutdown (required by NEC 690.12 since 2014) is a safety device that de-energizes all DC wiring between the panels and inverter within 10 seconds of grid loss. This protects firefighters who might cut live wires during a roof fire. String-inverter systems need a separate relay module (SolarEdge has one built into their optimizers, or you can add a third-party rapid-shutdown relay). Microinverter systems (Enphase, APsystems) have rapid-shutdown at the inverter level and inherently meet the code. Your installer's one-line diagram must clearly show which rapid-shutdown device you're using; if it's missing or unclear, the electrical inspector will reject the permit and ask you to add it. The device typically costs $500–$1,500 and takes a few days to integrate, so catch this early.
Can I install the solar panels myself, or does Murphy require a licensed installer?
Murphy allows owner-builder work for owner-occupied residences under Texas Property Code § 401.006. You can perform structural/roofing work (mounting) yourself if you obtain an Owner-Builder License from the Collin County Construction Trades Program (rarely required for residential solar, but sometimes the city asks). The electrical work, however, almost always requires a licensed electrician in Texas and Murphy. The electrical inspector will want to see a licensed electrical contractor's name and license number on the rough inspection checklist. If you try to wire it yourself and the inspector discovers this, your permit will be rejected and you'll have to hire a licensed electrician to re-do the work and pass re-inspection. The labor cost difference is worth avoiding the rejection.
What if Murphy's inspector finds a problem during rough inspection?
The inspector will note any deficiencies on the inspection report (called a 'fail' or 'failed with corrections'). You have typically 30 days to fix the issue (e.g., add a missing disconnect, reseal a roof penetration, fix a conduit-fill violation) and request a re-inspection, which is often free if scheduled within 30 days. If you miss the 30-day window, the permit expires and you'll need to pull a new permit (and pay the fee again). For electrical issues, you'll likely need a licensed electrician to sign off on the correction. Common re-inspection fixes: rapid-shutdown not wired correctly, DC disconnect label missing, AC breaker size incorrect, conduit not properly sealed, roof flashing not fully sealed. Most are quick fixes (1–2 days) and don't add significant cost.
Does Murphy require a structural engineer's letter if my roof is 15+ years old?
Not always, but increasingly yes. Some inspectors require a roof condition certification (from a licensed roofer) if the roof is over 10 years old; others waive this if the installer provides a detailed load calculation showing the roof is still adequate. To be safe, budget $200–$400 for a roof certification or engineer's letter if your home was built before 2009. A roofer can often provide this during a walkthrough in under an hour. If you skip this and the inspector asks for it, you'll have to re-submit and wait another 1–2 weeks, so it's better to include it upfront.
What happens if I export more power to Oncor than I use in a month?
Any excess kWh you export rolls forward as a bill credit to the next month under Oncor's net metering tariff (NODIS). The credit does not reset monthly; it accumulates and carries over indefinitely as long as you remain an Oncor customer. At the end of the year (or if you move), Oncor may have different policies about cashing out unused credits — some utilities pay out at wholesale rates (~$0.03–$0.05 per kWh), which is much less than retail. Check Oncor's current NODIS tariff to see their payout policy. For most residential customers, a well-sized system (one that produces slightly more than you consume annually) maximizes the credit and avoids year-end payout penalties.
If I add batteries, do I need a Fire Marshal review?
Yes, if the battery capacity exceeds 20 kWh. Most residential battery systems (Enphase IQ, Tesla Powerwall, LG Chem) are in the 10–15 kWh range per unit, so a single battery qualifies as residential and is usually pre-approved by the Fire Marshal. However, two or more battery units (20+ kWh total) trigger an official Fire Marshal review, which adds 2–3 weeks to the permit timeline and costs $50–$200 in review fees. The Fire Marshal checks siting (typically requires 5+ feet from windows and property lines), venting (batteries must not block or be blocked by vents), emergency access (firefighters need clear path to the battery cabinet), and electrical separation (DC and AC sections clearly marked). For a backup-power home (3–4 batteries, 40–50 kWh), expect 6–8 week timeline and plan for this from the start.
What is a 'Certificate of Occupancy' for solar, and do I need one?
For solar systems, Murphy typically issues a 'Final Certificate of Approval' or 'Final Inspection Sign-Off' rather than a true Certificate of Occupancy (that term is usually reserved for new construction or major building occupancy changes). After Oncor energizes your system and Murphy's final electrical and building inspections pass, the permit office will issue a letter or document stating that the solar permit is complete and the system is approved for operation. This document is important for resale (proof of permitted work), insurance claims, and any future bank/lender inquiries. Keep a copy in your homeowner files. If you ever lose the original, the city can re-issue a copy for a small fee ($25–$50).