What Are Preliminaries in a Building Quote or Quantity Surveyors Estimate?
- 22 hours ago
- 4 min read
If you've received a quote from a builder or an estimate from us (or another QS) and noticed a line item called "Preliminaries", "Builder's Preliminaries", or sometimes just "Prelims", you're not alone in wondering what it actually covers. It's one of the most common questions homeowners ask when reviewing a construction quote for the first time, and the answer matters more than most people realise.
The Short Answer
Preliminaries are the builder's indirect project costs. They cover everything the builder needs to set up, manage, and operate a construction site that isn't directly part of physically building your home. Think of it as the cost of running the project, rather than the cost of the bricks, timber, tiles, and labour that go into the building itself.
What Preliminaries Typically Include
Preliminaries cover a wide range of items that most homeowners wouldn't think about until they're standing on a construction site. These typically include:
Site establishment — Setting up the site before construction begins, including temporary fencing around the perimeter, site sheds and offices for the builder and tradespeople, temporary power and water connections, and site signage.
Scaffolding and access equipment — Scaffolding is one of the larger preliminary costs on most residential projects. Cranes, hoists, and other access equipment also fall into this category where required.
Site management and supervision — The site supervisor or foreman who coordinates tradespeople, manages the programme, and ensures the work is being carried out to the required standard is a preliminary cost. This is a significant component, particularly on larger or more complex projects.
Subcontractor coordination — The time spent by the builder's team scheduling, briefing, and managing the various subcontractors (plumbers, electricians, framers, tilers, and so on) is a preliminary cost, not a trade cost.
Safety and compliance — Workplace health and safety requirements in NSW are extensive. The cost of safety equipment, safety signage, compliance documentation, and any traffic control measures required around the site are all preliminary items.
Insurances and permits — Contract works insurance, public liability insurance, Home Building Compensation Fund (HBCF) insurance, and any council permits required during construction are typically included in preliminaries.
Waste management — Skip bins, rubbish removal, and general site clean-up throughout the build are preliminary costs. On a full home build these can be surprisingly substantial.
Site amenities — Portable toilets, hand-washing facilities, and other amenities required for tradespeople on site are a preliminary cost most homeowners don't think about.
Cleaning — Both ongoing site cleaning during construction and the final builders' clean before handover are typically covered under preliminaries.
Security — On some projects, particularly those in built-up areas or running over an extended period, security costs may also be included.
Why Do Preliminaries Vary Between Quotes?
This is where it gets important from a budgeting perspective. Preliminaries are not a fixed percentage of the build cost. They vary depending on:
Project size and duration — A longer project means more weeks of site supervision, more skip bin collections, more scaffold hire, and more site running costs. Preliminaries on a 12-month project will be proportionally higher than on a 3-month project of similar scale.
Site constraints — A tight inner-city block with limited street access, no on-site storage space, and close neighbours requiring hoarding along boundaries will attract significantly higher preliminary costs than a generous suburban block with easy access and room to move.
Access conditions — If a crane is required due to restricted access, or if materials need to be hand-carried through a narrow side passage, those additional costs sit in preliminaries.
Level of site management required — A complex custom home with many subcontractors and a high-specification finish requires more active supervision and coordination than a straightforward project. That additional management time is a preliminary cost.
This variability is one of the reasons two builders can quote the same project at quite different totals even when their trade costs are similar. A builder who prices preliminaries thoroughly upfront is less likely to issue variations later. A builder who prices them lightly to keep the headline number competitive may recover the difference through the contract.
What Percentage of a Build Should Preliminaries Be?
As a general guide, builder's preliminaries on a standard residential project typically range from around 8% to 15% of the total construction cost, depending on the factors above. On a complex project with significant site constraints, they can be higher. On a straightforward project with a short programme and easy access, they may sit toward the lower end.
If a builder's quote shows very low or zero preliminaries, it doesn't mean the project will be cheaper overall. It generally means those costs are either absorbed into the trade rates or will surface later as variations. An experienced quantity surveyor reviewing a builder's quote will always check whether the preliminaries allowance is realistic for the project type and site conditions.
Why Does This Matter to You as a Homeowner?
When comparing quotes from multiple builders, it's tempting to focus on the total figure and assume the cheapest quote represents the best value. But two quotes with different preliminary allowances are not directly comparable without understanding what each includes.
A builder who includes $45,000 in preliminaries on a $600,000 project has priced the running of the site properly. A builder who includes $12,000 on the same project has either made some assumptions that may not hold, or is planning to recover the balance through variations once the contract is signed.
Getting an independent review of a builder's quote from a quantity surveyor before you sign gives you visibility over exactly this kind of difference, so you're comparing quotes on equal terms rather than just headline totals.
Any Questions?
If you've received a builder's quote and want an independent review of the costs before you commit, CPP Quantity Surveyors provides construction cost advice for homeowners across Sydney and Regional NSW. Contact us to discuss your project.
By Gary Uys, FAIQS CQS, Director - CPP Quantity Surveyors
📞 (02) 9629 3495
