The first step to figuring out if building your own home will save you money is to work out what the raw materials such as bricks are going to cost you, and how much of everything you’ll need. Although it’s only one cost element of buidling your house, it’s a good place to start.
Some of the other money and time costs to consider when building your own home include:
- Skilled and unskilled labour needed
- Quality of finishes
- Plan costs
- How complex the design is
- The difficulty of constructing the building based on the plans
- Council approval
- How you’ll be funding your build
Get the Build Aid Building and Pricing Guide
If you’re really serious about building your own home, get a copy of the Build Aid Building and Pricing Guide. It breaks down, section by section, everything that goes into building a house.
Don’t be shocked when you see how big the job could be - not all of it will apply to the kind of home you’ll be building. But everything you need to know is inside it, including formulas for calculating how many bricks you’ll need, and all of the legal requirements you to need to meet if you want your home to pass municipal inspection.
Start with detailed drawings of what you plan to build. If you’re working with an architect, he’ll provide these, but if not, hire a licensed draftsman. They’re a lot cheaper than an architect, and they’ll be able to translate your scribbled sketches into something a town council won’t reject without giving your plans some thought.
Simplify to get to a rough material cost
Costing a house looks (and is) involved, but a good way to get started is to simplify things by pretending it’s one long wall. This is because a lot of calculations are based on the total square meterage of wall you’re building, not how much space the house will take up on te property.
From primary school mathematics, we know that the formula for area is length x height. The lengths of each wall are listed on your plans, so add them up - use a spreadsheet for this. Height is much easier, because it’s the same all over the house.
To get an idea of much wall you’re building in square metres, multiply total length of our imaginary wall by the standard height.
Tip: Exterior walls are always two bricks thick, so remember to count them twice.
Do the math
From here, it’s mostly a case of building a spreadsheet that lists all the materials you’ll need, and basing that on the surface area of your giant wall.
The Building and Pricing guide contains formulas that can tell you how much sand, gravel, and cement you’ll need per m2 of wall. Materials for plastered finish rely on total area, too, as do estimates of how much paint you’ll need.
On a separate spreadsheet page, you can also start to add up totals of items that you’ll need a fixed number of, like doors, window frames, and light switches.
Plan for wastage
For items like bricks and cement, add 10-20% more than you think you’ll need to your total requirement. A reality of building is that there’s a fair amount of wastage - bricks get broken, left-over cement dries out at the end of the day. If you’ve only planned for exactly what you need, you could end up caught short.
Most big hardware stores offer quotes based on detailed plans, and some will even generate them for free. It’s incredibly useful, but don’t rely on it for your own costing. Generally, stores will only include the items they sell themselves, and won’t show you how they arrived at any of their totals.
These quotes are worth asking for, though, because they can give you an idea of how close your estimate is, and they might also reveal needed materials you’d failed to consider.
Remember the bigger picture
Material cost is just one aspect of a build, but costing materials is still worth doing if you’re trying to decide whether building your own home will give you the kind of savings that would make it worthwhile.