Can single-skin walls be insulated internally without stripping back to brick?

[flashbac]

Can single skin walls be insulated internally without stripping them back to brick?

I wouldn't think so. We did internal insulation in my last flat and it was taken back to brick, insulated plaster boards fitted and skimmed on top.

What is currently there?

Of course you can insulate whatever there is, you just build a stud wall, put insulation behind it and then board it. However, it is can be very inefficient depending on what there is, and you may want to ensure that you make the whole thing breathable, which would be much easier if you remove what is there.

Again, depending on what it is it may not be that big a job.

Yes.

But I would recommend taking the plaster off. It is only on the external wall, not the whole room. Older houses may have lime plaster which is sometimes rather thick, and the insulation will add more thickness. Expanded foam boards have twice the insulation as the same thickness of mineral wool, and support plasterboard better. You do not need battens, as older builders used to think. Use plasterboard with a foil backing, and taped joints, which prevent water vapour passing through from the room.

This is a good time to run any cables for additional sockets, switches, LAN, TV outlets, phone, alarm etc. Expanded foam must not touch PVC cables as it causes the plasticiser to migrate. Oval conduit is good because it can enable new cable to be pulled through in future alterations or repairs. The insulation board can be grooved to fit. Put in plenty of sockets at the modern height.

You will need to reposition skirting, and detailing round windows and doors. A skilled carpenter has the technique for scribing corner joints, it is better than a mitred cut.