Can You Install Solar Panels on a Garage Roof?

Yes, you can install solar panels on a garage roof in the UK, provided the structure is strong enough to support the weight and has a suitable orientation and angle to capture sunlight effectively.

Installing panels on a garage roof is an increasingly popular option for UK homeowners and landlords looking to harness solar energy, reduce energy bills, and contribute to a greener future. 

This guide dives into the feasibility, benefits, risks, costs, and installation process of fitting solar panels on a garage roof, tailored to help you make an informed decision.

Is It Possible to Install Solar Panels on a Garage Roof?

Yes, you can install solar panels on a garage roof, provided it meets specific structural and orientation requirements. 

Garages, whether attached or detached, often have sufficient roof space and can be an excellent alternative to the main house roof, especially if the latter is shaded or structurally unsuitable. 

According to the Energy Saving Trust, solar panels work best on roofs that are south-facing, unshaded, and pitched between 30° and 40° for optimal sunlight capture in the UK. 

However, garage roofs facing east or west can still generate 15-20% less energy than south-facing ones, making them viable in many cases.

Key Considerations for Garage Roof Suitability

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  Roof Orientation and Angle: South-facing roofs are ideal, but east or west orientations can work. The pitch should ideally be 30°-40°, though flat garage roofs can use angled mounting systems. Read our guide on the best angle for solar panels to get a better understanding.
  
  
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  Structural Integrity: The roof must support the weight of solar panels (approximately 15-20 kg per panel) and withstand wind loads. A professional structural assessment is recommended.
  
  
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  Shading: Avoid roofs shaded by trees, buildings, or chimneys, as shading reduces panel efficiency. Optimisers can mitigate minor shading issues.
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  Roof Condition: Older or damaged roofs may need repairs before installation to ensure longevity, as panels typically last 25 years. Check out our guide on whether you would need to replace your roof before installing solar panels.
  
  
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  Planning Permissions: Most garage roof installations fall under permitted development rights in the UK, meaning no planning permission is required unless the garage is in a conservation area or listed building. Always check with your local planning authority.

Pros and Cons of Installing Solar Panels on a Garage Roof

What are Risks of Installing Solar Panels on a Garage Roof?

While generally safe, installing solar panels on a garage roof carries some risks that homeowners and landlords should consider:

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  Structural Failure: If the garage roof is not assessed properly, the weight of panels could cause damage. A structural engineer should confirm the roof can handle the load (typically 15-20 kg per panel plus wind forces).
  
  
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  Fire Hazard: Poorly installed electrical components, like inverters or wiring, could pose a fire risk if not compliant with IET Wiring Regulations (BS 7671). Always use MCS-certified installers.
  
  
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  Weather Damage: High winds or storms could dislodge panels if mounting systems are substandard. Ensure installers use robust, weather-resistant mounts.
  
  
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  Reduced Efficiency: Shading from nearby structures or trees can lower energy output, though optimisers can help.
  
  
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  Warranty Issues: Non-compliant installations may void panel or roof warranties. Verify installer certifications and warranties beforehand.

To mitigate these risks, hire an MCS-certified installer and ensure compliance with building regulations.

How Many Solar Panels Can Fit on a Garage Roof?

You can typically fit 6-15 solar panels on a UK garage roof, depending on its size and layout, with each panel covering about 1.7m² and producing 350-450W for a total system size of 2.1-5.25kWp.

A typical UK domestic solar panel is about 1.7m x 1m, covering roughly 1.7m². According to the Energy Saving Trust, an average 3.5kWp system requires 10-20m² of roof space, accommodating 6-12 panels. Most UK garages have smaller roof areas than main houses, so let’s break it down:

What are the Costs of Installing Solar Panels on a Garage Roof?

A 4kW system (suitable for a typical garage) costs £6,600-£8,100, including installation. However, the cost of installing solar panels on a garage roof varies based on system size, roof complexity, and additional components. Here’s a breakdown:

Ways to Reduce Costs

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  Group Purchasing: Schemes like Solar Together offer bulk discounts through community buying.
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  Funding Options: Check for grants via the Energy Company Obligation (ECO4) or Warm Homes Local Grant for low-income households.
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  Scaffolding Savings: If roof repairs are planned, combine them with panel installation to reduce scaffolding costs.

Use our Solar Panel Calculator to find the ideal system size for your home and see how much you could save on electricity bills.

What is the Installation Process for Garage Roof Solar Panels?

Installing solar panels on a garage roof follows a structured process, typically completed in 1-2 days by MCS-certified professionals. Here’s how it works:

1. Site Assessment

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  A professional evaluates the garage roof’s orientation, pitch, shading, and structural integrity.
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  They confirm compliance with building regulations and permitted development rights.
  
  

2. System Design

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  The installer designs a system (e.g., 3.5-4kW) based on roof space and energy needs.
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  They select panels, inverters, and mounting systems tailored to the garage.

3. Scaffolding Setup

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  Scaffolding is erected for safe roof access, unless the garage is low enough for ladders.
  
  

4. Mounting Installation

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  Roof anchors and an aluminium frame are secured to the roof, angled at 30°-40° for optimal sunlight.
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  For flat roofs, ballasts or tilted frames are used to achieve the correct angle.
  
  

5. Panel Installation

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  Panels are fixed to the mounting structure and positioned to maximise sunlight exposure.
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  Bolts are tightened to ensure stability against wind and weather.
  
  

6. Electrical Wiring

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  Panels are wired to a solar inverter, which converts DC to AC electricity for home use.
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  The system is connected to the home’s consumer unit, with power switched off during wiring for safety.
  
  

7. Grid Connection and Testing

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  The installer registers the system with the Distribution Network Operator (DNO).
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  The system is tested to ensure it meets IET Wiring Regulations and generates power efficiently.
  
  

8. Completion and Certification

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  A completion certificate is issued, confirming compliance with building regulations.
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  You’re guided on applying for SEG payments.

What are the Types of Mounting Systems for Garage Roof Solar Panels?

Professional installers use robust mounting systems to ensure solar panels are secure and efficient. Common types include:

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  Roof Anchors and Frames:
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  Ballasted Mounts:
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  Microinverters or Optimisers:
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Always ensure mounts comply with building regulations and are installed by certified professionals. Learn more about standards at MCS Certified.

FAQs

Can I install solar panels on a garage with a flat roof?

Yes, flat garage roofs are suitable with ballasted or tilted mounting systems to achieve the optimal 30°-40 angle. Ensure proper installation to avoid roof damage.

Do solar panels on a garage roof affect my home’s energy performance certificate (EPC)?

Yes, solar panels can improve your EPC rating by enhancing energy efficiency, potentially increasing property value by up to 15%.

Can I move solar panels from my garage to another location later?

Yes, panels can be relocated, but it requires professional reinstallation, which may cost £1,000-£2,000 depending on complexity.

Are there specific regulations for garage roof solar panels?

Installations must comply with IET Wiring Regulations (BS 7671) and building regulations for structural and electrical safety. Use MCS-certified installers.

Can I use solar panels on a rented garage roof as a landlord?

Yes, but you’ll need tenant permission and must ensure the lease agreement clarifies ownership and maintenance responsibilities.

What happens if my garage roof needs replacement in the future?

Panels can be removed and reinstalled during roof replacement, but this may cost £1,000-£2,000. Plan ahead to avoid unexpected expenses.

Our Verdict

Installing solar panels on a garage roof is a viable and rewarding option for UK homeowners and landlords seeking to reduce energy bills, lower carbon emissions, and potentially increase property value. 

With the ability to fit 6-15 panels on most garage roofs, generating up to 4,500 kWh annually, this investment can significantly offset electricity costs. While there are risks like structural concerns or shading, these can be mitigated with professional assessments and optimisers. 

The installation process is straightforward with MCS-certified installers, and costs (£6,600-£8,100 for a 4kW system) can be offset by SEG payments and potential grants. 

By using Eco Answers’ Quote-Comparison Tool, you can connect with trusted suppliers to get the best deal and start your journey towards sustainable energy. Explore your options today and take a step towards a greener, more cost-effective future.