Before comparing building quotes in Christchurch, check that each builder has priced the same home, on the same site, with the same specifications. Then compare what is included, what is excluded and which costs are still allowances.
The useful question is not simply “Which total is lower?” It is “What will I receive for this price, and what remains for me to pay?”
This guide includes a comparison checklist you can use before choosing your builder.
Start with the same information
Create one dated pricing pack for every builder. Include your drawings, specification list, available site reports and a short record of decisions still to be made.
Keep track of revisions. If you change the garage size or kitchen layout after one builder has priced the work, ask for an updated response before comparing totals.
For a Christchurch section, make a separate list of site questions: foundation assumptions, drainage, access and any work needed before construction starts. Record which documents each builder has used to price those items.
Still assessing the land? Start with our buying a section in Christchurch checklist.
Is it a quote or an estimate?
An estimate is an informed indication of cost, not a fixed price. A quote offers specified work for a stated price. Consumer Protection explains that an accepted quote cannot simply be increased without agreement to extra work or a change in scope. Consumer Protection: Quotes and estimates
Ask the builder to identify exactly what they have provided. A concept-stage budget and a detailed construction quote serve different purposes.
Write these details at the top of your comparison:
- Document date and revision.
- Quote or estimate.
- Plans and specifications referenced.
- GST treatment.
- Validity period.
- Items awaiting confirmation.
Your building quote comparison checklist
Copy this table into your own document. In each quote column, record included, excluded, allowance or unclear, followed by the relevant amount or document reference.
Do not treat an empty cell as zero cost.
| Item to compare | Quote A | Quote B |
|---|---|---|
| Total price and GST treatment | — | — |
| Drawing and specification revisions | — | — |
| Floor area, including how the garage is counted | — | — |
| Design, surveying and engineering | — | — |
| Ground investigation and foundation assumptions | — | — |
| Excavation, spoil removal and retaining | — | — |
| Council fees and applicable contributions | — | — |
| Water, wastewater, stormwater, power and fibre connections | — | — |
| Cladding, roofing, windows and insulation specifications | — | — |
| Kitchen, bathrooms, appliances and flooring | — | — |
| Heating, ventilation, lighting and electrical fittings | — | — |
| Driveway, paths, fencing, landscaping and window coverings | — | — |
| Prime cost allowances and provisional sums | — | — |
| Owner-supplied items and installation responsibilities | — | — |
| Payment stages and proposed programme | — | — |
| Variation charges and approval process | — | — |
This is a comparison worksheet, not a statement that every item belongs in every builder’s price. The aim is to establish who supplies each item and where its cost sits.
For the wider project budget, see our Christchurch new-build cost guide.
Understand allowances before comparing totals
What is a provisional sum?
A provisional sum is money allowed for work that cannot yet be priced firmly because the detail is incomplete. Ask what information would allow the builder to confirm that cost.
What is a prime cost allowance?
A prime cost allowance sets aside money for an item you have not yet selected, such as a sink. Choosing a more expensive item can increase the price. Installation is not included unless the documentation says it is.
MBIE explains both terms in its guide to tenders and quotes.
For each allowance, ask:
- What quantity and specification does it cover?
- Does it include GST, delivery and installation?
- How are differences between the allowance and actual cost calculated?
- Is a builder’s margin added, and how is it applied?
- What happens if the actual cost is lower?
An allowance needs an explanation, not just a number.
Turn exclusions into a separate budget
Create an “outside the building quote” list.
For every excluded item, record the supplier, current price or estimate, payment timing and who will coordinate the work. Leave unresolved costs clearly marked until you have enough information.
For example, if one proposal includes fencing and another excludes it, request a separate fencing price for the second option. Do not assume the difference between the two building totals represents a saving.
Keep two figures visible:
- The amount payable under the builder’s proposal.
- Your working budget for the complete project.
Avoid counting the same cost twice. If you revise an allowance already included in a quote, adjust that allowance rather than adding its full replacement value on top.
Check what “fixed price” covers
Ask the builder to show you the agreed scope and any clauses that could change the amount payable.
Then check how variations will be handled. A variation is a change to the contracted work. Before approving one, request a written description, its price and any effect on completion dates or consent requirements.
MBIE’s contract guidance says the agreement should explain how variations are agreed before work continues. It also recommends checking their cost, timing and consent implications. MBIE: Contracts for your building project
A useful question to ask is:
“If I change a selection after signing, what information will I receive before I approve the extra work?”
Keep that answer with your comparison notes.
Compare the team as well as the price
Ask who will be your day-to-day contact, who supervises the work and how you will receive progress updates.
Request the contractor’s disclosure statement. It provides information about the business, the key contact’s experience, insurance and any guarantees or warranties offered, including limitations.
For residential building work costing $30,000 or more including GST, the contractor must provide the disclosure statement and standard consumer checklist before you sign. You can also request them for smaller work. MBIE: Consumer protection disclosure and checklist
Our comparison table does not replace those official documents.
Before accepting a proposal
Send your shortlisted builder one written list of outstanding questions. Ask for the answers to be incorporated into the final documents where appropriate.
Check that you can identify:
- The exact home and specification being priced.
- The included work and exclusions.
- Remaining allowances and assumptions.
- Payment stages and timing.
- The process for changes.
- Responsibilities through completion and handover.
A written building contract is required for residential building work of $30,000 or more including GST. Have your lawyer review it before you commit, particularly the price-adjustment, payment and delay provisions. MBIE: Building contracts
Common questions
Can I compare builders using price per square metre?
Use it as an initial reference, then check the details. Record the floor area used in each calculation and whether the price includes the garage, site work and the same finishes. A rate without those details leaves important differences unresolved.
Should I reject a quote with provisional sums?
Not automatically. Ask why the work remains provisional, how the allowance was calculated and what would resolve the uncertainty. Keep unanswered items visible when deciding whether you are ready to proceed.
What if one quote is much cheaper?
Ask the builder to explain the difference in writing. Compare the work, products and responsibilities before deciding it offers better value. Consumer Protection recommends considering experience, reliability and quality alongside price. Consumer Protection: Comparing quotes
Planning your Christchurch build?
Bring your section details, available plans and a short list of priorities to your first conversation with Tailored Homes. Include the questions you still need answered about the site, specification and budget.
Explore our Christchurch custom home building service, or contact Tailored Homes to discuss your new build.
This guide provides general information. Your contract and site circumstances matter; obtain independent advice before signing.
