A builder’s allowance is one of the most misunderstood items in any new build or renovation contract. Understanding exactly how it works — and what to do when your selections cost more or less than the allowance — can save you thousands.
If you have ever signed a building contract or renovation quote you have almost certainly encountered the term “provisional sum” or “prime cost allowance.” These are the line items that sit in a contract as a placeholder — an estimated cost for something that has not yet been specified or selected. They are also one of the most common sources of budget blowout in Australian residential construction.
Understanding builder’s allowances before you sign anything is one of the most financially protective things you can do as a homeowner.
What Is a Builder’s Allowance?
A builder’s allowance — sometimes called a prime cost (PC) allowance or provisional sum — is a dollar amount that a builder includes in a contract to cover the cost of an item or category of work that has not yet been fully specified at the time of signing.
Common examples include:
- Tiles — “PC allowance: $65 per square metre supply and lay”
- Stone benchtops — “PC allowance: $800 per lineal metre”
- Kitchen cabinetry — “PC allowance: $18,000”
- Appliances — “PC allowance: $8,000”
- Tapware and fixtures — “PC allowance: $3,500”
- Electrical fittings — “PC allowance: $2,500”
The allowance represents what the builder estimates these items will cost based on a standard or mid-range specification. When you make your actual selections, the real cost is compared to the allowance and the difference is either added to or deducted from your contract sum.
What Is the Difference Between a Prime Cost and a Provisional Sum?
These two terms are related but distinct:
Prime Cost (PC) Allowance
A prime cost allowance covers the supply cost of a specific item — a tap, a light fitting, a tile — where the exact product has not yet been chosen. The builder’s labour to install the item is typically priced separately. If you select a tap that costs more than the PC allowance, you pay the difference. If it costs less, you receive a credit.
Provisional Sum
A provisional sum covers work where the full scope is not yet known — earthworks, rock excavation, or complex structural elements. Both the supply and the labour are estimated. Provisional sums are inherently less predictable than prime cost allowances and carry more risk of variation.
A builder’s allowance is not a budget. It is an estimate made before your selections are confirmed. The gap between the allowance and your actual selections is where most renovation budgets blow out.
Are Builder’s Allowances Set at a Fair Level?
This is the critical question — and the honest answer is: not always. Builder’s allowances are set by the builder, often based on the most basic specification they expect a client to select. A tile allowance of $55 per square metre supply and lay sounds reasonable until you visit a tile showroom and discover that the tiles you actually want cost $120 per square metre. The variation is yours to pay.
In some cases allowances are set deliberately low to make the initial contract price look more competitive. In other cases they genuinely reflect a mid-range specification and the builder expects most clients to come in close to the allowance. Knowing which situation you are in requires either experience or an independent advisor.
How Do You Know If Your Allowances Are Realistic?
The most effective way to assess whether your builder’s allowances are realistic is to get independent pricing on the same categories before you sign. This is exactly what a building consultancy or procurement partner does — they can tell you whether a $65 per square metre tile allowance is achievable for the specification you have in mind, or whether you should expect to spend $120 and plan your budget accordingly.
At Skyline Collective we work with homeowners at the pre-contract stage to review builder’s allowances, identify where they are likely to be exceeded, and use our trade procurement network to source materials at pricing that often comes in at or below the builder’s allowance — for a better quality product.
What Happens When Your Selections Exceed the Allowance?
When your actual selections cost more than the allowance, the builder issues a variation. This is an addition to your contract price. Variations are a normal part of the building process but they need to be managed carefully:
- Always get variations in writing before proceeding with the selection
- Compare the variation cost to what you could pay through an independent supplier or procurement partner
- Remember that the builder applies a margin to PC items — typically ten to twenty percent on top of the supply cost
- Consider whether the selection is worth the variation cost or whether a comparable alternative within the allowance exists
Can You Use Your Own Suppliers for PC Items?
In some contracts, homeowners have the ability to supply certain PC items directly — purchasing tiles, tapware or appliances independently and providing them to the builder for installation. This is known as owner-supplied or free-issue supply. It is not always available and not all builders accept it, but where it is permitted it gives you direct access to trade pricing without the builder’s margin applied on top.
This is one of the most effective ways to use a procurement partner — sourcing PC items at trade pricing and supplying them directly to your builder, keeping the margin saving in your pocket rather than your builder’s.
The Bottom Line
A builder’s allowance is a starting estimate, not a guarantee. Understanding what your allowances are set at, whether they are realistic for your specification, and how to use procurement to come in at or under allowance is one of the most financially impactful things you can do before signing a building contract.
