Can You Install Solar Panels on a Garage Roof?

Solar Panels on a Garage Roof: Everything You Need to Know

Not everyone has a suitable house roof for solar panels. Maybe your main roof faces north, is heavily shaded by trees, or has conservation area restrictions that prevent panel installation. In these situations, a garage, outbuilding or workshop roof can provide an excellent alternative mounting location for a solar array.

At ALPS Electrical, we have installed solar panels on garages, agricultural buildings, workshops and other outbuildings across Teesside and North Yorkshire. This guide covers everything you need to consider before installing panels on your garage roof.

Is Your Garage Roof Suitable?

The same principles that apply to house roofs also apply to garages. The key factors are orientation (south-facing is ideal, but east-west works well too), pitch angle (25-40 degrees is optimal), structural integrity (the roof must be able to support the weight of the panels and mounting system), and shading (the panels should receive direct sunlight for most of the day).

One advantage of garage roofs is that they are often lower than house roofs, making them easier and safer to work on. This can reduce scaffolding costs compared to a house installation. However, garage roofs are sometimes constructed to a lower structural specification than house roofs, so a thorough structural assessment is essential before proceeding.

Flat Roof Garages

Many garages have flat or nearly flat roofs. This is not a problem for solar installation. We use angled mounting frames that tilt the panels to an optimal angle (typically 15-25 degrees on flat roofs) to maximise solar generation. The mounting system adds minimal load to the roof structure, but we always verify the roof can support the additional weight before proceeding.

Pitched Roof Garages

Garages with pitched roofs (concrete or clay tiles, slate, or metal sheeting) are installed using the same mounting rail systems we use on house roofs. The panels sit on aluminium rails that are secured to the roof structure through the tile or sheet covering, with waterproof flashings to prevent any leaks.

How Many Panels Fit on a Garage Roof?

A single garage roof (approximately 15-18 square metres) can typically accommodate 4-6 standard solar panels, producing a 1.7-2.7kW system. A double garage roof (30-36 square metres) can typically fit 8-14 panels, producing a 3.4-6.3kW system. These are useful system sizes that will make a meaningful impact on your electricity bills, particularly when combined with battery storage.

Planning Permission

Solar panels on a garage roof generally fall under permitted development rights, meaning you do not need planning permission provided the panels do not protrude more than 200mm beyond the plane of the roof, the building is not in a conservation area, listed building curtilage, World Heritage Site or Area of Outstanding Natural Beauty, and the panels are not visible from a highway (for buildings other than the main dwelling).

If your property is in a conservation area or the garage is within the curtilage of a listed building, you will need to check with your local planning authority before proceeding. We can advise on this during our site survey.

Cable Routing

One consideration specific to garage installations is the cable route between the garage panels and your house consumer unit or inverter. If the garage is attached to the house, this is straightforward. If the garage is detached, the cables need to cross the gap, typically by running underground in ducting or along an overhead route. Underground ducting is preferred as it is neater and more durable. We excavate a shallow trench between the buildings, lay the cable in appropriate ducting, and backfill.

Is a Small Garage System Worth It?

A common question is whether a 2-3kW system on a garage roof generates enough electricity to justify the investment. The answer is yes, particularly for households that are at home during the day. A 2.5kW system in the North East will generate approximately 2,100-2,400 kWh per year. At current electricity prices, that represents £550-650 in annual savings if you use most of the electricity directly. Even with partial self-consumption, the payback period is typically 7-9 years, and the panels have a 25-30 year performance warranty.

Adding a small battery (5-6kWh) increases self-consumption further and extends the savings into the evening, improving the overall return on investment.

Get a Garage Roof Assessment

If you are interested in solar panels for your garage or outbuilding, contact ALPS Electrical for a free survey. We will assess the structural suitability of the roof, plan the cable routing, design the optimal panel layout, and provide a clear fixed-price quote with no hidden costs.

Watch Related Installations

See real installations from our team that demonstrate the topics covered in this article.

Frequently Asked Questions

1 How much do solar panels cost in the North East?

A typical 4kW residential solar panel system in the North East costs between £5,000 and £7,000 including installation and VAT at 0%. Larger systems of 6-8kW range from £7,000 to £10,000. Prices vary depending on panel brand, roof complexity and whether you add battery storage. ALPS Electrical provides free, no-obligation quotes with a full breakdown of costs and projected savings.

2 How many solar panels do I need for my home?

Most UK homes need between 8 and 16 solar panels depending on electricity usage, roof size and orientation. A typical 3-bedroom semi-detached house uses around 3,500kWh per year, which can be met by a 4kW system (8-10 panels). Larger detached properties with electric vehicles or heat pumps may need 6-10kW systems (14-24 panels). We conduct a detailed survey to recommend the optimal system size for your specific needs.

3 Do solar panels work in the North East and in winter?

Yes, solar panels work effectively in the North East. While the region receives less sunshine than the south of England, modern high-efficiency panels like the Jinko Tiger Neo and JA Solar panels we install generate significant electricity even on overcast days. The North East receives approximately 1,100-1,200 kWh/m² of solar irradiance annually. Winter output is lower but panels still generate electricity — pairing with battery storage ensures you maximise every unit generated.

4 How long does solar panel installation take?

A standard residential solar panel installation typically takes 1-2 days. If you are adding battery storage, this may extend to 2-3 days. Commercial installations can take 1-2 weeks depending on system size. The full process from survey to switch-on usually takes 4-8 weeks, including the DNO notification or G99 application if required.

5 Do I need planning permission for solar panels?

Most domestic solar panel installations fall under Permitted Development and do not require planning permission. However, you will need to apply if your property is listed, in a conservation area, or if panels will protrude more than 200mm from the roof surface. Ground-mounted arrays over 9m² also require permission. ALPS Electrical handles all planning considerations and will advise you during the survey.