Quick answer
What homeowners need to know
Compare renovation quotes by aligning scope, assumptions, allowances, exclusions, GST, programme, payment, warranty and variation procedures—not total price alone.
Create a comparison sheet and ask each contractor to clarify every blank or different assumption.
Key takeaways
- Give every builder the same information before you compare anything.
- Provisional sums and prime cost allowances need close attention.
- Read the exclusions as carefully as the inclusions.
- A useful quote explains scope, assumptions, allowances, exclusions, programme and responsibilities.
Quotes, contracts & delivery
How to compare renovation quotes on equal terms
Give every builder the same information before you compare anything. If one contractor saw the drawings and another priced from a walk-through, their numbers cannot be compared fairly. Send the same drawings, specifications, selections and site notes to each, set the same submission date, and ask them to list any assumptions they made where your information was incomplete.
Provisional sums and prime cost allowances need close attention. These are placeholder amounts for items not yet fully defined, such as tiles, fixtures or unknown ground conditions. A quote with low allowances can look cheaper but will rise once real selections are made. Check whether each allowance is realistic for your choices and whether a margin applies when an allowance is exceeded.
Read the exclusions as carefully as the inclusions. Common gaps include consent fees, rubbish removal, scaffolding, temporary protection, making good existing finishes and GST. Put each quote into a simple spreadsheet with a row per scope item, and mark anything excluded or unclear. Ask each contractor to price or confirm those gaps in writing before you make a decision.
Scope before solutions
Decisions to make before committing
Settle these points before an idea becomes an order, contract or construction instruction.
Create a comparison sheet and ask each contractor to clarify every blank or different assumption.
completeness of design and scope information
number and size of provisional allowances
decision speed, variations and access constraints
Practical sequence
A step-by-step planning process
- 01
Define the exact outcome you need and how success will be checked.
- 02
Issue the same scope and information to every contractor being compared.
- 03
Align inclusions, exclusions, allowances, GST, programme and payment terms.
- 04
Record selections, approvals and variations through one agreed communication process.
- 05
Complete inspections, defects, certificates, warranties and maintenance information at handover.
Cost and time
How to build a more reliable budget and programme
A fixed price or completion date needs a measured scope and a site visit. For residential building work, check the current contract and disclosure requirements and obtain legal advice where the agreement or risk warrants it.
Use the calculator, then request a site-specific assessment.
Risk control
Common mistakes to avoid
- Choosing the lowest total before normalising scope can lead to expensive variations.
- accepting a total without reading its assumptions
- authorising changes without written cost and programme effects
Accuracy and compliance
Use current official information
Primary sources used for this guide
- Why contracts are valuableBuilding Performance (MBIE)
- Home renovation and repairConsumer Protection New Zealand
- Planning a successful buildBuilding Performance (MBIE)
Common questions
Frequently asked questions
How many renovation quotes should I get?
Get enough to compare approaches without overwhelming yourself or the contractors. A small number of detailed quotes from builders with relevant experience is usually more useful than many rough ones. What matters most is that every contractor prices the same scope and information, so differences reflect pricing and method rather than different assumptions.
What is the difference between a building quote and an estimate?
A quote is generally a firm price for a defined scope, while an estimate is an approximate figure that can change. Many renovation quotes still include provisional sums or allowances that can move. Read the document to see which parts are fixed, which are estimated and what happens if actual costs differ from an allowance.
Why are renovation quotes so different from each other?
Large differences usually come from scope interpretation, allowances, exclusions and how risk is priced, rather than labour rates alone. One builder may have included items another left out, or priced unknowns differently. Line up each quote against the same scope list and ask contractors to explain the gaps, because the reasons often show how each would run the job.