Solar Panels – In roof or On roof

Solar Panels – In roof or On roof

November 18, 2015 Off By Simon

In roof or On roof solar panels - Which to go for?

If you are interested in solar panels the way they are mounted on the roof is something to consider.  There are a number of methods of mounting solar panels but they boil down to two main types; In roof solar panels and On roof solar panels.

We talk to architects a lot and from our discussions with them they would favour an on roof solar array to an in roof.  This is for the practical reason of maintenance and replacement that will be required in the future.  The design life of a roof is in excess of 60 years but the solar panels will need replacing in 20 - 30  years.  With In roof panels there is a major maintenance event built in because of this, so On roof panels can be the better choice in the long run.  However we have outlined the advantages and disadvantages below so you can decide.

More info:

On Roof Solar Panels:

chicken wire2Mounting the solar panels on a bracket that sits proud of the roof.  The brackets holding the solar panels are secured mechanically to the timber joists of the roof.  This can require drilling through the tile or slate,  this hole then needs to be weatherproofed.  This is the most common system to mount solar panels and probably the cheaper option as well.  Flat Plate solar panels, evacuated tubes and solar pv panels can be mounted this way.


  1. Cheaper typically - see our solar panel prices here
  2. Installing solar panels on roof allows for easier and cheaper maintenance in the future.
  3. Mounting system for nearly every roof type is available.


  1. Drilling through tiles or slates needs to be weather proofed adequately.
  2. Wind load increased which may be problematic in high wind areas.

In Roof Solar Panels:

solar panels

This method allows the solar panels to be mounted as part of the roof structure similar to a velux window.  The solar panels are secured directly to the timber joists and then a flashing is installed around the solar panels to weather proof the entire array.  Only flat plate solar panels and solar pv panels  can be installed in this manner,  evacuated tubes are always installed On Roof.


  1. More Aesthetic
  2. Less exposure to wind buffeting
  3. Once installed correctly the system should be weather proofed for the life time of the solar panels


  1. The solar panels will have to be removed from their flashing to be replaced at the end of their life or if they need maintenance - this can be more costly than on roof options.