By now you should have worked out that i’m not a huge fan of the standard brick and tile homes on offer in 95% of our housing estates. They tend to be cold and lifeless, boring and not inspiring houses to live in. As well as this they are not the most thermally efficient homes to live in. While brick does have some thermal mass properties, the mass is on the outside of the insulation so it does not equalize the temperature inside the house. Brick is also not a good insulator, so it heats up in summer and gets very cold in winter without providing much of a barrier to temperature extremes. I suppose the main reason it is so popular is because of the perception of a solid home, giving the owners a sense of security as opposed to lightweight cladding which many people perceive as flimsy and cheap.
Brick veneer as a construction method is also popular because the project builders have got the method down to a T. The prefabricated pine wall frames go up quickly, then the brick skin goes up to the eaves level quickly. There’s no working out what to do because all of the trades people involved are well practiced. Minimal cutting and mucking around.
The common alternatives:
The common alternative to brick veneer is a timber stud frame with lightweight cladding, such as fibre cement products (sheet or weatherboards), metal cladding such as corrugated colorbond, real timber weatherboards, plywood sheeting, foam boards with render etc. If it wasn’t for the insulation packed between the framing, lightweight cladding would be no better off than brick veneer. Heat loss in winter would be extreme and heat gain in summer would be intolerable. Luckily the walls can be packed with insulation batts and wrapped with sarking to control the temperature to a certain degree, although it is limited by the amount of insulation that can be packed into the width of the stud frame. Usually R2.0 or maybe R2.5 batts. There is a limit to the effectiveness of this insulation though and it does not provide any thermal mass to equalize the temperature throughout the year.
Most of the homes I design are based on lightweight cladding because it does provide flexibility in the design and in my opinion looks better than face brick. Sometimes a bit of feature brickwork combined with lightweight cladding can look good and give a house enough character to make it stand out from the ugly sea of brick and tile boxes. Most architectural home designers in Australia prefer to use lightweight cladding for these reasons too. Descriptions such as “coastal feel”, “beach house”, “contemporary” etc.
The lightweight wall cladding is often combined with sheet roofing such as corrugated colorbond over timber rafters or trusses. Again this material relies heavily on added insulation, otherwise it would be as comfortable as living in a tin. Winter and summer would be unbearable.
Some other exciting alternatives
There are alternative building techniques which I am keen to explore more in the future. Some have been around for centuries such as hay bale houses, mud brick homes, rammed earth, earth covered houses. Some which are fairly new on the residential scene such as insulated panels more commonly used in commercial refrigeration. The main advantage of these techniques both old and new is thermal performance, they all do an excellent job of insulating the inside of the home from the temperature extremes we experience in Australia.
I am particularly interested in hay bale houses. I have seen a number of examples and also an episode of Grand Designs which featured a hay bale house construction. I suppose there are a number of factors which I like. Number 1 is that it reminds me of “lego” building blocks, the inspiration behind me becoming an architect. The modular shape determines the layout but there is massive scope for creativity also. I also like the do it yourself potential for anyone with a bit of construction nous. With a bit of training anyone could have a go. There are a number of skills involved in the finishing. Surprisingly the finished product is very water tight, fire resistant and vermin resistant. The insulation properties are almost unbeatable, with the exception of the roofing which would likely have to use traditional techniques. One day i promise I will build a hay bale home. They are just so organic and warm in character.
Another product has come to my attention lately. “Bondor Insul Living” – it is made up of 140mm external panels of polystyrene sandwiched between 2 layers of colorbond steel. Once installed the interior wall joints are set with plaster and painted while the external joints are set and then texture coated with acrylic paint. The joints are then not visible at all, giving a flush modern finish. Interior walls are 90mm panels made up of the same product. The roof is also polystyrene sandwiched between roof sheeting and colorbond steel under. The Insul Living website has an excellent video demonstrating how the system goes together. The main advantages are quick construction, minimal waste, strong structure, great sound insulation and excellent thermal properties. The system is thoroughly thought out and very solid. I am currently modifying some of my designs for a client in Queensland who is keen to build some homes using the system and then market the products to builders. Visit the Bondor Insul Living website here.
Watch this space for future designs and built homes using some of these alternative construction techniques with excellent insulation properties and fast construction times.