How to compare builders’ estimates without getting lost in the totals

Find out what kind of number you have

Consumer Protection explains that an estimate is an indication of likely cost rather than a fixed price. A quote offers specified work at a stated price. Ask the builder to explain the basis of their offer and the circumstances in which the amount could change.

I would also ask what decision the number is intended to support. Are we testing whether the developing design looks affordable, or choosing a contractor for a documented job? That distinction helps everyone avoid treating an early conversation as the final price.

• What information was used to prepare this price?
• Is it an estimate or a quote?
• How long is the offer valid, and what assumptions depend on the proposed start date?

Check the information before checking the arithmetic

Ask each builder to identify the drawing revisions, specifications and site information they priced. MBIE recommends providing detailed information and checking that offers cover the same work, materials and fixtures.

I would keep a short record of anything discussed after the documents were issued. Perhaps you mentioned a different kitchen layout during a site visit. Has that idea found its way into one price but not the other? Resolve the intended design with your team, then send the same clarification to everyone still pricing.

Give allowances their own conversation

An allowance needs a little unpacking. MBIE describes a provisional sum as money allowed for work that cannot yet be priced firmly. A prime cost sum allows for an item you will select, and does not include installation unless stated.

Ask what product or work each allowance could realistically cover. A smaller allowance may reflect a different selection rather than a better price for your preferred one.

• Which items are allowances rather than settled prices?
• What selection or further information would allow them to be confirmed?
• Where are installation, GST and any applicable margins accounted for?

Try the kitchen comparison

Here is a hypothetical example. One builder has included cabinetry, a benchtop and installation. Another has allowed for cabinetry but expects you to organise the benchtop separately. Both have written 'kitchen' beside their figure.

I would ask both to describe the same finished kitchen, then confirm how their prices respond. Keep their original figures intact and put the clarification beside them. Do not quietly add your own guess to one total and present it as the builder's revised offer.

• Choose one area where the estimates differ.
• Write a plain description of what you expect to receive.
• Ask each builder to confirm inclusions, exclusions and any revised amount.
• Leave unanswered points marked as unresolved.

Bring the design team into the difficult gaps

If a price relies on an alternative product or a change to the design, I would ask the design team to review that suggestion before accepting it. Give them the actual proposal so the conversation stays specific.

Daniel from Warwick Gair Builders comments on the clarity of Modal Architecture's drawings and specifications in his published feedback. That is a useful aspect to explore when discussing your own project: how will design information reach the people pricing and building it?

Finish with a decision you can explain

I would want to explain why I preferred a builder after the outstanding questions were answered. Price matters, alongside relevant experience, references and confidence in how we will work together.

If you are planning a residential project and are unsure what information to have ready for pricing, bring that question to an initial conversation with Modal Architecture. We can discuss the next useful step.