Wider Walls: A Simple Way to Boost Insulation

Standard timber-framed walls in WA are usually built with 90mm studs, which allow for R2.5 to R2.7 insulation. Some of my projects use 140mm studs instead, which fit enough insulation to reach R4.0, a meaningful step up in thermal performance.

There's a nice side benefit too. The extra wall depth gives you wider window sills, which can make a real difference to how a room feels, more depth for light to sit in, a spot for pot plants, or just a softer, more considered feel to the window itself.

It does mean slightly more material and a little less internal floor area, since the walls themselves take up more space.

Worth knowing

A 90mm wall, done well, with good orientation, shading and airtightness, can still perform beautifully. Wider studs are one way to push performance further, not a requirement every home needs. Whether it's worth it comes down to your goals for the project and how the design is already shaping up.