House size

The size of your house is the biggest factor in your cost per square metre. First-time builders are often surprised that as the house size increases, the square metre cost goes down! 

The culprit here is the one-off, big-ticket items that go into every house. The kitchen is a perfect example; this is a significant build cost that’s included in every design. It doesn’t matter whether your house plan is 150sqm or 200sqm, it still only includes one kitchen - so with a larger floor plan, the kitchen cost is averaged out over a much bigger area, leading to a lower total cost per square metre.

Even when a bigger house plan includes a bigger kitchen, the cost doesn’t increase proportionally to the size of the house. An expansive open kitchen in a 300sqm home will cost more than a smaller kitchen on a smaller plan, but the cost doesn’t double to match the size of the house. As a result, the square metre cost will still be lower than it would be for a smaller build.

The cost of hiring tradespeople works the same way. The difference in price for an electrician or plumber to complete a 150sqm house, compared to a 200sqm house, is minimal - so again, you end up with a similar cost averaged out over a larger area.

Location

The location of your section can make a surprisingly big difference to your square metre cost, simply because of the travel required to get to the site. When you consider the heavy machinery needed to carry building materials, plus paid travel time for tradies, it starts to make sense that a house in Diamond Harbour will cost more per square metre than the same house built in Christchurch, five minutes from the building depot.

Land Category

If you’re building on TC1 land, your builders will be able to use a standard foundation (at a standard cost). However, if you’re on TC2 or TC3 land, the increased risk of land damage in the event of an earthquake means your house will need an engineered foundation. This adds an engineering design cost to your build budget, bringing up your overall square metre cost. 

Delays during construction

Build delays can also have an impact on the overall square metre cost. While the cost of materials and labour doesn’t change, the ongoing build cost still increases. 

This is because of the ‘background’ services that are required throughout the build, from project management to site fencing, temporary services, and even portaloo hire. 

What does this mean if you’re considering building?

At the moment, the cost per square metre is very high for houses under 180sqm - so if you can stretch your budget to a larger floor plan we generally recommend it. 

There are some design choices that can help to reduce your square metre cost, without compromising on quality. Your choice of cladding, tiled ensuite bathrooms, the complexity of your floor plan and the heating solution you use can all make a difference. 

If you’re thinking about building and aren’t sure what your square metre cost will be, give us a call. We can talk you through what you can expect, and the reasons why.