required amount of insulation for a HMO in london

[jomcroon]

hi guys
i getting a property ready for a HMO inspection and one of the many regs. is to do with loft insulation reg says 100mm between joist and 175 over ive got 100 between ok but loft is all chip boarded out and all screwed down surely i dont have to put 175 on top of boards ?

cheers

 

[flameport]

Insulation over the boards, or remove them, add insulation and reinstall boards over the top using loft legs, timber or similar.

100mm insulation in a loft is totally inadequate for any building.
275mm is the absolute minimum required.
More is desirable.

 

[jomcroon]

Yes that makes sense
Many thanks