Install rooftop solar.

Modern solar technology is highly efficient, even in the UK's overcast climate, capturing daylight rather than direct sunlight to power your home. This guide outlines the costs, regulations, and practicalities of installing a solar array on your roof in 2025/26.

What Does the Work Involve?

• Structural Survey: An assessment of your roof’s integrity to ensure it can handle the weight of the panels and wind loading.
• Scaffolding: Setting up safe access platforms, which is a mandatory safety requirement for most UK rooftop installations.
• Roof Mounting: Fixing stainless steel brackets to the roof rafters and attaching aluminium rails.
• Panel Installation: Securing the solar PV modules to the rails and connecting them in "strings."
• Electrical Integration: Installing the DC/AC inverter, generation meter, and connecting the system to your consumer unit.
• Battery Storage (Optional): Integrating a battery system to store excess energy for use after dark.
• Commissioning: Testing the system, notifying the District Network Operator (DNO), and providing MCS certification.

Typical Costs

The cost of solar depends heavily on the size of the system (measured in kilowatts peak, or kWp) and whether you include battery storage. Prices have stabilised in 2025, but labour and scaffolding remain significant factors.

Factors affecting the price include the brand of panels (Tier 1 vs. budget), the type of inverter (string vs. micro-inverters), and your roof material. Slate or rosemary tiles often require more labour-intensive mounting than standard concrete tiles.

How Long Does It Take?

• Pre-installation: 2-4 weeks for DNO applications and structural checks.
• Scaffolding Setup: 1 day prior to the installation.
• Main Installation: 1-2 days for a standard domestic system.
• Handover & Certification: 1 week for all final paperwork and MCS registration.

DIY or Professional?

Solar installation is not a DIY project. While a competent DIYer might be able to physically bolt panels to a roof, the electrical work involves high-voltage DC current which is extremely dangerous. Furthermore, to access the Smart Export Guarantee (SEG)—which pays you for the energy you send back to the grid—your system must be installed by an MCS-certified professional.

Failure to use an MCS-certified installer usually means you cannot claim export payments, and your home insurance may be voided in the event of a fire or structural failure.

Choosing the Right Tradesperson

• Check Certifications: Ensure they are MCS (Microgeneration Certification Scheme) accredited and members of a consumer code like RECC or HIES.
• Electrical Qualifications: The lead electrician should be NAPIT or NICEIC registered (Part P compliant).
• Warranty Review: Look for at least 10 years on the inverter, 25 years on panel performance, and 2-5 years on workmanship.
• Questions to Ask:
  • "Will you handle the G98/G99 application to the DNO for me?"
  • "Does the quote include scaffolding and bird proofing?"
  • "Can you provide a projected yield report based on my roof's specific orientation and shading?"

UK Regulations

• Permitted Development: Most solar installs don't need planning permission, provided they don't protrude more than 200mm from the roof slope.
• Listed Buildings/Conservation Areas: You will likely need full planning permission and should consult your local council first.
• Building Regulations: The installation must comply with Part P (Electrical Safety) and Part A (Structural Safety).
• DNO Notification: Your installer must notify the local grid operator so they can manage local power loads.

Common Problems

• Shading Issues: Even a small amount of shade from a chimney or tree can significantly drop the output of an entire string of panels. Use optimisers to mitigate this.
• Poor Roof Condition: Installing panels on a 50-year-old roof that needs replacing in 5 years is a costly mistake. Fix the roof first.
• Inadequate Bird Proofing: Pigeons love the warmth under panels. If you don't install mesh, they will nest, create mess, and potentially damage wiring.
• Undersized Inverters: If your inverter is too small for your array, you will "clip" your peak generation, losing out on free energy during mid-summer.

Frequently Asked Questions