How do you insulate house walls that don't have cavities?

Answer 1

You can do one of two things. Firstly, you could erect a second wall outside the house. Of course there are many instances where this would not be feasible.

In such cases, one would have to baton the walls from the interior to create a cavity, which would then be filled with some form of material with a high insulation rating i.e. fibreglass wool or rigid insulation boards.

To provide further insulation, special plasterboard (drywall) can be purchased with higher insulation ratings than regular plasterboard. However, using these thicker boards would further encroach on the room in question, which might not be very desirable at all since the batons would already take a couple inches away.

Alternatively use an External Wall Insulation system.