Which energy providers offering 'room in roof' insulation under GBIS?

I am currently with Octopus Energy who have advised that they will NOT be offering 'room in roof' insulation, they are only offering cavity wall insulation or loft insulation.

I live in a solid stone terrace house (no cavity wall to my knowledge) and there is already loft insulation under the floorboards of the attic bedroom (where I sleep). There is no insulation under the sloping roof in the attic which is what I was wanting to use GBIS for.

Does anybody know of an energy provider that is offering 'room in roof' insulation?



  • Suppliers aren't offering the same things everywhere in the country - they rely on local contractors/installers to do the actual work.

    You really need to phone a few to ask what they are offering in your area (or at least say where you are in the country so any replies can be relevant to you/your area). 
    I'm not an early bird or a night owl; I’m some form of permanently exhausted pigeon.
  • No one will offer "Room in Roof" insulation.

    Loft and cavity wall insulation is quick and easy, low risk, high profit.  Easy to quote, estimate for with fair accuracy.

    "Room in Roof" can be difficult to reliably quote for as there are far too many potential pitfalls to the process.  It's an invasive mucky job.  If it's done from the inside..... who pays for the re plastering, painting and decorating too...... will you want the whole room(s) re-doing?  If it's done from the outside you could end up re-roofing, who pays for that?

    The only way i would take on "Room in Roof" insulating would be by an hourly rate.  Once you start knocking old plasterwork about, whole ceilings can fall down and large areas of the plaster on walls can come away if you're unlucky.  If you do it from the outside a scaffold will be needed at great cost, and it's easier to re roof the whole roof than try to put back a part of it that you've removed.   

    To do it properly, you have to do it from the inside.
  • Most roofs are not designed to have insulation right up against the tiles and this might give rise to condensation and ultimately rotting of the roof timbers.  Or it just might not work because the eaves are designed to let air in for ventilation.  I would advise against "room in roof" insulation unless you actually construct the room and heat it.  There will still be air flow in the cavity behind the walls of the room. 
  • You create a space between the insulation and the tiles or slates by fitting a batten or a pair of battens, add insulation to finish flush with internal side of roof trusses. Then add a moisture barrier, then add as much insulated backed plasterboard as you can get away with.

    Done it several times and it is very much worth doing. The three downsides are it's a very dirty start removing the internal old plasterwork, you have no idea what extra work / repairs you'll have to do and how much replastering and decorating I'll need doing afterwards. 
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