Basic considerations for calculating the price of wall frames and roof trusses
House frames and trusses have been standardized to a certain extent over the years to comply with general building requirements in Australia. The way they’re fabricated nowadays has also been continuously improving. While previously, timber trusses and wall frames were assembled in-situ (on-site) from the ground up, these days you can buy prefabricated ones that are delivered to the construction site directly. It also means that you can have them customized as well.
Let’s have a look at some of the factors that must be considered in the designing, construction, and assembly of timber trusses in Sydney and New South Wales to get a basic price estimate:
- Beyond the red tape: Around 15% of your overall costing is spent on council fees and getting permits. Before the actual design of a rafter or a truss is finalized for building, there’s a lot of red tape to get through. Whether you’re building with steel or timber, you first need to get the approval from the right building council before construction begins. You’ll need to acquire either a Developmental Application (DA) or a Construction Certificate – sometimes even both. To accompany the design, structural engineering plans are also required.
All the required paperwork is basically about getting approval from the right authorities and takes anywhere from around 30-100 days to receive the permit. Once you’ve got it, it’s time to get the builders involved. Contractors typically submit tenders for such jobs, and you can browse through their proposals to find one that suits your budget, your material specifications, and your structural requirements the best.
- Size of the building: The basic costing of a timber truss depends on the size of your dwelling, as it determines the design and slope of the structure. Keep in mind that each truss has to be designed to exact specifications in order to complement the overall structural integrity of the building. This will affect the average price of a truss, as the companies sell them at different rates to different buyers depending on the project requirements.
- Type of building or project: The building type and project classification affect the average costing of trusses. First of all, the type of building structure will determine the strength, design, and overall integrity of the truss. The type of project – e.g. new building vs. a renovation – can also have a lot of impact on how much you’ll have to spend.
Note that trusses incorporated in renovation projects will cost more due to more increase in the cost of material and labour, so they’re definitely on the expensive side. Similarly, if you’re adding an extension to your existing building (like a garage), then it’s also going to affect the price because the new structure has to be seamlessly integrated into the old one which would require a certain level of expertise, skill, and experience.
- Cost of labour: 35% of your overall budget is spent on labour costs. A prefabricated frame and trusses are usually sold at lower labour costs than carpentered ones, but the price is also susceptible to the highs and lows of the market price of timber.
- Exposed truss costing: Exposed trusses are not just a part of the structure, but they also have to be aesthetically pleasing enough to complement the overall interior design. The property owner has to decide wheater to paint or stain the exposed trusses (pine trusses should be painted, Merbau timber has to be stained).
This means that an extra effort and thought has to be put in their design and installation. Moreover, such trusses are designed by seasoned and experienced professionals. If you also include the quality of the materials (appropriate type of treated timber)and cost of chord ties then exposed trusses will definitely cost more than regular ones.
- Choice of materials: 50% of your costing goes into the acquisition of materials. The price of wood frames and trusses is typically lower than steel, but general fluctuations in the market can vary this figure. The reason why steel costs more is because it is twice as heavy and requires much more labour to be assembled properly. There's also a difference in price between untreated and treated timber for interior and exterior use.
Pro Tip: Make sure you maintain good communication with personnel designing/quoting your frames and trusses
Benefits of getting a timber truss:
Here’re a few reasons why timber is the preferred material for the design and construction of trusses:
- Lower overall costing: Compared to steel, using timber for your house’s structure can help you save around 10-20% in your costing. That’s a lot of price margin when you’re working with a limited budget.
- Manufacturer automatically certifies the frames and trusses so there's no extra cost involved as opposed to hiring an engineer to come onsite and getting approval for onsite work.
Need to discuss requirements for your frame and trusses construction project in Sydney or New South Wales? Call ABC Frames and Trusses today on (02) 9623 3100