Building cost per square metre: Why comparing square metre rates is flawed thinking

It still baffles us that people are still asking for the building cost per square metre when they are researching their new home build or renovation. To us, it is flawed (and outdated) thinking and if you are choosing a builder based solely on the square metre rate, you are making a BIG mistake… Huge.

Why is this such a big mistake, you ask? There are two main reasons.

Reason #1 — Not all square metres are the same quality

Think back to the last time you bought something by the metre. It might have been some carpet. Fabric for some curtains. Or even a length of rope at the hardware store.

Now, let me ask you this question… When comparing the range of products (the different types of carpet, fabric, rope or whatever), did the cost per square metre vary? Of course it did. Why? Because the product you were purchasing likely came in varying degrees of quality.

One carpet, for example, may be made of wool, while another is made from synthetic. One might be handcrafted while another manufactured at a high volume. One might be more durable and suitable for high-traffic areas while another might only be suitable for light use.

Some fabrics are mass-produced while others are handspun. Some will be lined or have a rubber backing while others will not. Ropes will also be made of different materials, come in different thicknesses and have varying degrees of strength and durability.

As you can see, so many variables on just these three things. Now think about all the variables on all the different components that make up a house… Carpet, curtains, bricks, tiles, taps, timber, lights, paint, glass, grass. We could be here all day listing things out.

Would it be logical to compare all these things solely on the square metre rate alone? When you think about it, if we were only comparing products based on a cost per square metre, then on one end of the scale, you would be getting amazing quality at an extremely good price. On the other end, however, you would be paying a premium price for a poor-quality product.

So, comparing one builder’s price per square metre to another builder’s price per square metre is simply not logical. And we haven’t even touched on the quality of the workmanship and the experience of the builder.

Reason #2 — Not all square metres are the same quantity

Now, let’s talk about why comparing building cost per square metre is even more ludicrous when we compare the shape of each home.

I think we can all agree that the overall square metre area of a home can be made up of different designs and layouts right? Some houses are effectively square boxes while others are rectangles or L-shaped, U-shaped and so on. While each of these homes may have the same overall square metre dimensions, the amount of building materials that go into constructing each home is going to be considerably different.

For example, consider two homes that both have an internal area of 200 square metres. A more complex shaped home can have a 78% greater wall area, requiring more windows, more doors, more brickwork, more guttering, more gyprock, and significantly more paint — even though it’s the same square metre size on paper.

If you were comparing each home on building costs per square metre, then on paper, the more complex shape would mean you are getting more materials for your money. But what if you prefer the layout of the simpler design? Would you forgo a better floor plan for your requirements for what may be considered better value for money?

And what about the quality of the work? Is the builder going to offset the cost of the extra materials by going cheap on the labour?

It’s fair to say that comparing house builds on square metre rates alone simply does not work. Doesn’t seem so logical to compare homes based on the building cost per square metre now, does it?