How can I insulate a single brick wall

Ok , I hope this answer helps you out , I have actually done this for a customer 1st paint the inside face of the wall in a waterproof sealer , then leave a air gap , place 100mm wide doc on the floor and build a timber stud work wall 50mm in from the internal face and using 4x2 timber Then you use 100mm thermal insulation in the stud work wall , staple a breathable membrane over the top of this , and finally use blue sound absorbent plasterboard This should go the trick for you Hope this helps ?

You could use a 90mm graphite polistyrene external wall insulation panel or you could do similar on the internal. The panels come pre finished with a render

An external wall insulation system is the most cost efficient way in my opinion The thermally insulated, protective, decorative exterior cladding procedure involving the use of expanded polystyrene, mineral wool, polyurethane foam or phenolic foam, topped off with a reinforced cement based, mineral or synthetic finish and plaster can be design to active what U value you need and will keep the work to the outside there fore no extra cost mess and disturbance to the house . If it is a internal wall it can be insulated by building a stud wall next to it ,100 mil should be sufficient ,and use the space between the studs to house the insulation ,thermal or sound proof etc

Stud timber wall Infront of brickwork all around garage once this done insulate between timbers using kingspan insulation once this completed vapour barrier over this then use insulated plasterboard on top then plaster over complete room be insulated nice and up to regulations