Choosing a site and getting planning permission

As well as the guidelines below, you can try our Renewable Selector to see if your home is suitable for solar PV, and if it's not, find other possibilities. 

Choosing a site

Planning permission

Insurance

 

Choosing a site  

 

Orientation and tilt

Your roof should ideally face due south at a pitched angle of around 30° from the horizontal to give the best overall annual performance. Installations at any pitch and facing anywhere to the south of due east and due west are feasible, although output and income will be reduced. Installation is not recommended on roofs facing north.

This table shows the percentage of the ideal annual output you will get for a system with a different orientation and tilt:

Solar PV tilt effect
 

Seasonal performance

The chart below shows a typical seasonal spread of energy generation for a system of 3kWp facing south. The winter months generate significantly less electricity compared to the summer months.

Solar PV effect of season
 

Site location

The amount of electricity generated by a solar PV system can also vary depending on where you live. Northern areas receive slightly less energy from the sun over the year. For example, a 1kWp system will generate less electricity in Northern Scotland than it would in Cornwall. However, solar electricity is still worthwhile - the differences aren’t substantial. You can get an estimate of how much a system will generate in your location (and how much it will earn) using our Solar Energy Calculator.

 

Shape of roof area

Solar PV arrays are made up of modules of about 1.5 square metres which allows most available roof shapes to be accommodated. Typical UK installations are around 15 to 25 square metres. For example, a 3kWp system could comprise 15 panels taking up an area of 20 square metres and will generate roughly 2,500kWh per annum.

 

Shading

All the modules are connected, so any shading on a single module will affect the performance of the whole array. A system can tolerate some shading early or late in the day without much reduction of overall output but it should not be shaded between 10am and 4pm. Nearby trees, chimneys, TV aerials and vent pipes are all common causes of shading and should be accounted for before any installation.

Solar electricity doesn’t necessarily require direct sunlight and can still generate electricity on cloudy days. You could get as much as a third of the energy on a cloudy day as you would get on a sunny day at the same time of year.

 

Planning permission  

In England, Wales and Scotland, you don't need planning permission for most home solar electricity systems, as long as they're below a certain size - but you should check with your local planning officer, especially if your home is a listed building, or in a conservation area or World Heritage Site: we can only give general guidance here. You'll find full details on the government's legislation sites:

 

Permitted development rights for solar PV (roof mounted)

Permitted unless:

  • panels protrude more then 200mm when installed.

Your local Building Control Office may want to check that your roof structure is suitable – your installer should be able to advise on this.

 

Scotland

In Scotland, permitted unless:

  • installed on any part of the external walls of the building if the building contains a flat
  • panels when installed on a flat roof are situated within 1 metre from the edge of the roof or protrude more than 1 metre above the plane of the roof 
  • panels when installed project higher than the highest point of the roof (excluding the chimney)
  • the building is within a conservation area or World Heritage Site and the solar PV or solar thermal equipment is installed on a roof which forms the front of the building and is visible form the road.

The solar PV equipment must, as far as is reasonably practical, minimise its effect on the amenity of the area and be removed when it is no longer needed or used for domestic microgeneration.

 

Insurance  

Many building insurance will cover you under the terms of your current policy if you have solar PV panels installed on the roof of your home. But always contact your current insurance provider for advice before having solar PV panels installed, because:

  • the installation of solar PV panels is a material change to your home’s structure that your insurance provider needs to know about
  • you need to know exactly what your insurance covers - does it cover damage caused by the installation; does it cover theft?
  • some types of installation, such as ground-mounted systems, may not be covered as standard.

As a precaution we recommend that you confirm in writing with your insurance provider that you have had a solar PV system installed and ask them to confirm in writing that they have received your notification and the terms of the cover being provided by them. If you purchase a home with a solar PV system already installed or change insurance provider later, make sure that they are aware of system before accepting any quote.

 

Before you start...

If you're thinking about installing a system to generate your own heat, make sure your home is as well insulated as it can be so your heat-producing system can be most efficient.

Focus on improving insulation and tackling draughts.