Solar · Fitting
Should I choose in-roof or on-roof panels?
Short answer
On-roof panels sit on rails above tiles and are usually cheapest on an existing roof. In-roof kits replace tiles, look flush and suit re-roofs, new builds and extensions, but typically cost more and can run slightly warmer. In-roof kits must be MCS 012 certified with a fire rating suitable for the distance to your boundary.
Last checked 24 September 2026 · 1 source
In more detail
- MCS 012 scope includes roof-integrated kits and PV tiles.
- MIS 3002 Appendix C: fire classification vs boundary distance (Approved Document B).
The facts, dated
- 01In-roof kits must have fire performance rating appropriate to the array location (MIS 3002 5.8.1)
standard · UK · checked 24 September 2026 · MCS
Sources
Last checked: 24 September 2026