Extensions

Should the line of the new cavity and blockwork be flush with the existing cavity and blockwork?

Anonymous user 23/02/2024 - 3.03 PM

I'm looking to extend the kitchen to the back of my house by removing the rear wall and extending outwards by roughly 2m continuing the line of the existing walls on either side. Now the existing external wall is 265mm wide and I think current standards mean my new external wall (which I would like to run flush externally to the existing) should be closer to 330mm wide with a much larger cavity. I'm just wondering what would be considered best practice here when setting out the new wall. - Should the new wall buildup match the 265mm of the old wall buildup so that the internal blockwork and cavity line through. Then line both internally with insulation backed plasterboard to bring them up to current standards? Or - Should the new wall be built to current standards of 330mm with a larger cavity so that the new blockwork does not line through with the existing blockwork. The old wall buildup would then be internally lined with insulation backed plasterboard to bring it to current standards and so they both line through flush with one another? Thanks! Paul