Two quotes for the same house can differ because they price the same work differently, or because they describe different work. Only the first is a real comparison. Before the totals mean anything, the two documents have to be lined up so that each one covers the same scope, the same selections and the same assumptions about the site.
Compare scope before price
Start with what each quote is pricing. Check that both are based on the same drawings, at the same revision, and the same specification. A quote prepared from an earlier set of plans is pricing a different house, even if the difference is small.
If the drawings are still changing, ask each builder to price the same revision and to state which revision the quote is based on. A comparison made across two different sets of drawings measures the drawings as much as the builders.
Then check the boundaries of the job. Where does each quote start and stop? Demolition, site preparation, service connections, driveway, fencing, landscaping and retaining are all places where one quote may include work that another leaves to the owner.
Make a single list of those boundary items and mark each quote against it: included, excluded or not mentioned. The not-mentioned column is the one to resolve first, by asking each builder to answer in writing.
Read inclusions and exclusions line by line
An itemised quote lists what is included, item by item, so it can be checked against the drawings and the specification. A quote with a few broad headings asks the reader to assume what sits under each one.
Exclusions deserve the same attention as inclusions. An exclusions list says what the price does not cover, and every item on it is either someone else’s cost or a later decision. Put the two quotes’ exclusions side by side and note each item that appears in one list and not the other.
Look closely at items described in general words, such as standard fittings, or a finish named without saying which product. The specification should name the product, or the quote should say how it will be chosen. Where neither does, the line cannot be compared with anything.
Provisional sums and prime cost items
Some lines in a quote are allowances rather than prices. A prime cost item, often shortened to PC item, is an allowance for something not yet selected, such as tapware, appliances or floor coverings. In general terms it covers the supply of the item; the quote or contract says whether installation is included in the allowance or priced separately.
A provisional sum is an allowance for work whose extent cannot be known yet, such as rock excavation, where what lies below the surface is not yet known. In general terms it covers the work itself, labour and materials, because the quantity is what is uncertain.
Both are allowances, and the draft contract should explain how each one is adjusted once the selection is made or the work is known: how the difference between the allowance and the actual cost is treated, including whether a margin applies. Read that clause in each draft contract.
Allowances are not a fault in a quote. Some decisions cannot sensibly be made before signing, and some ground cannot be seen before it is dug. An allowance is how a quote marks those items openly, so they can be discussed rather than assumed.
When comparing, note which items each quote treats as an allowance. One quote may carry a PC item for an appliance that another prices as a named, selected product. The totals are then measuring different levels of certainty, not different costs.
Compare allowances, not just totals
Two quotes can reach different totals partly because their allowances are set at different levels. A lower allowance lowers the total on paper without changing what the finished item will cost. That difference arrives later, as an adjustment.
List every PC item and provisional sum in each quote, with the amount and what it is meant to cover. Then ask whether each allowance matches the selections the owner actually intends to make. That list is one of the first places to look for the gap between two quotes.
An allowance can also be set for a different standard than the owner intends. Checking each one against a real product, or a realistic scope of work, before signing is the step that brings an allowance close to a price.
Check the assumptions about the site
A quote is built on assumptions about the block: its site classification, its slope, what is below the surface, and where services connect. Those assumptions affect what has been allowed for in the footing design, site works and drainage until the reports and design documents confirm the basis for the build, and they can be stated or left unstated.
Ask what each quote assumes and what it is based on, such as a soil report and a survey. Ask what happens if the site turns out differently once work starts. Conditions that cannot be seen before excavation can only be priced once they are found.
On an established block, add the questions specific to a rebuild: what comes down, how services are disconnected, and what the previous building may have left below ground. Those items can be set out in one quote and absent from another.
What to ask once the quotes are lined up
With the scope, exclusions, allowances and site assumptions aligned, the remaining differences are genuine. Ask each builder to explain them. Ask how variations will be priced and agreed, because every allowance and every site assumption is a place where a variation can start.
Ask what is handed over at the end: which certificates, drawings and product information the owner receives. It is part of the scope even though it is not built on site, and it is easy to compare once it is written down.
Then compare the draft contracts as well as the quotes. The payment schedule, the variations clause and the treatment of allowances are all set there, and two quotes with similar totals can sit on contracts that handle those things differently.
A quote should be specific enough to build the contract on. At Cyberidge, quotes are itemised, so each line can be checked against the drawings and the specification before anything is signed.
Common Questions
How do I compare builder quotes?
Line them up before comparing totals. Check that both are priced from the same drawings and specification, compare inclusions and exclusions line by line, list every provisional sum and prime cost item, and check what each quote assumes about the site.
What is a provisional sum in a building quote?
An allowance for work whose extent cannot be known when the quote is prepared, such as rock excavation where what lies below the surface is not yet known. It is replaced by the actual cost once the work is done, and the contract sets out how the difference is treated.
What is the difference between a prime cost item and a provisional sum?
In general terms, a prime cost item is an allowance for supplying something not yet selected, such as tapware or appliances. A provisional sum is an allowance for work whose quantity is uncertain, covering labour and materials.
What should an itemised building quote include?
Each part of the work as a separate line that can be checked against the drawings and specification, a clear list of exclusions, every allowance with its amount and what it covers, and the assumptions the price relies on about the site.
Why are two quotes for the same house so different?
One reason is that they may not be pricing the same thing. Different drawing revisions, different exclusions, allowances set at different levels and different site assumptions all change a total. Once those are aligned, the remaining difference can be compared directly.
Comparing quotes for a build in Adelaide? Start with a free initial consultation.