Building Materials for Walls (and their Thermal Value)

When constructing a new home – you should aim to make it the most thermally efficient property possible. It will make living more comfortable and also drastically decrease your electricity bill as the need for air conditioning during both the cooler and warmer seasons won’t be as demanding. Appropriately rated and quality home insulation is essential to guaranteeing fantastic thermal efficiency – but if you want to go that extra step further then you should take into account the thermal value of your building materials as well. Not sure where to start? Right here is a good place so join us as we take a look at some popular building materials for walls and how well their thermal efficiency rates.


There are a few different methods you can use when building a home from bricks, but overall, bricks have a decent R-value (R0.44) which will increase when combined with other materials. Let’s take a look at a couple of popular brick wall methods.

Brick veneer walls

brick veneer wall holds the exterior appearance of a double-brick home. However, the single layer of bricks is only placed on the outside to conceal the wooden or steel frames of the house (with plaster on the inside). Think of it as siding – it doesn’t actually hold up the structure as such but simply acts as a decorative (yet functional) exterior layer. 

They have an R-value of 0.51 and don’t carry that much thermal efficiency on their own. Additionally – they don’t have very good acoustic properties and, due to the wooden construction, there’s a high risk of termites attacking. You may also consider a reverse brick veneer wall – which features the brick wall internally and other materials externally. This can actually be more thermally efficient when paired with the right insulation for your home.

Double brick walls

The famed double brick home is an iconic Victorian staple that provides a gorgeous aesthetic as well as quality comfort with a staggering R-value of approximately 1.3 – which, for a building material, is quite high. As the name suggests – there are two layers of bricks with an air gap between them. Unlike brick veneer walls double brick walls actually support your home’s structural integrity. If you remove the bricks then your home will be unable to stand.

If it wasn’t obvious by the high R-value – double brick walls are great insulators and will increase the thermal efficiency of your home greatly. The double brick will also combat moisture penetration and since there are no wooden features in the wall there’s a less likely chance of rodents such as termites appearing. It also has acoustic properties and will muffle outdoor noises. Of course, with double brick walls being so beneficial – they can also be quite expensive to build and an obstacle when it comes to renovating.


Concrete walls are fantastic if you’re looking for a more modern aesthetic. They can be poured and formed on-site or off-site (precast concrete). Concrete walls can last a long time, are highly flexible in terms of being shaped and are very strong. They also have fantastic thermal efficiency (the specific R-value will vary on the denseness of the concrete) and are heavily resistant to fire and water damage. One of the downsides to concrete walls is that they must be made exactly to measurement during the casting phase as once they’re set, they cannot be altered easily. It also requires specialised equipment to create – making it one of the pricier options.


Weatherboard is quite a popular material for walls in Victorian homes. They have an approximate R-value of 0.45 meaning they’re pretty poor insulators and will require some quality insulation to get them up to scratch. This is often a problem with older weatherboard homes that lack insulation as they can get very cold in the winter and hot in the summer. They’re simply constructed – featuring a timber frame with the weatherboard cladding on the outside. 

This is a cost-effective method that has its drawbacks such as poor thermal properties and a large amount of maintenance. The visual aspect of a weatherboard home doesn’t do very well against the elements and will need repainting every few years (this number will vary depending on the climate).

Are you looking for insulation for your home?

Insulation Essentials is the best place for quality, premium insulation products and accessories. We stock several types of insulation in varying R-values so you can find the perfect fit for your home. We also offer an installation service (with delivery), so you know that your home insulation is installed correctly.

If you’d like to find out more about our products and services, please give us a call on 03 8339 7111 or fill out the contact form on our website.