Guide
How to compare three renovation quotes
Everyone says get three quotes. Nobody says what to do when the three describe three different jobs, which is the normal outcome. The spread between them is usually not margin — it is different assumptions about demolition, about what is behind the linings, and about who carries the risk of being wrong.
$4,387
Modelled labour component of a full bathroom strip and refit — 134 trade hours priced at published median hourly pay for each trade. This is a model, not a price: it is employee pay before tax, not a charge-out rate, and it excludes materials, fixtures, waterproofing products, waste, consent and margin. The assumptions are set out below.
Tertiary Education Commission — Tahatū Career Navigator · 2026-07-30
Step one
Force the three quotes onto the same scope
- 01
Write the scope yourself, before you ask anyone
One page. Room by room, what stays and what goes, what is being moved, what standard of finish. Send the same page to all three. If you let each builder define the scope, you are not getting three quotes — you are getting three different jobs at three prices.
- 02
Ask each one to price demolition and disposal as a separate line
It is the line most often assumed away, and on an older house it is not small. A quote that folds it into "allow" is a quote you cannot compare.
- 03
Ask what each has assumed is behind the linings
Framing condition, insulation, wiring age, whether the wall is load-bearing, whether the floor is level. Three different assumptions here will produce most of your spread. Get them written down.
- 04
Ask where consent, inspection and engineering sit
In the price, excluded, or "at cost". Restricted building work needs a Licensed Building Practitioner and a record of work, and structural changes usually need an engineer’s design. Those are real costs and they belong in the comparison.
- 05
Ask for the contingency, as a number
Not "we will let you know". A quote with no contingency has moved the risk onto you without telling you. A quote with a stated contingency has priced honesty.
- 06
Only then compare the totals
And expect them to be closer than they were. Where a gap survives all five questions above, that gap is worth asking about directly — it is usually a genuine difference of method.
Step two
Know roughly what the labour in the job is worth
You cannot get a price for a renovation from public data. You can build the labour component up from published trade pay bands, which is enough to tell whether a quote is in a plausible universe. Here is that model for a full bathroom, with every assumption stated so you can disagree with it.
| Trade and task | Assumed hours | Median hourly pay | Modelled labour |
|---|---|---|---|
| Carpenter — strip out, framing, linings, fit-off | 40 | $31.25 | $1,250 |
| Plumber — waste, supply, fixture connections | 24 | $35.10 | $842 |
| Wall and floor tiler — floor and walls, waterproofing set-out | 32 | $32.21 | $1,031 |
| Plasterer — stopping and preparation | 16 | $30.77 | $492 |
| Electrician — circuits, extract, lighting | 10 | $41.35 | $414 |
| Painter and decorator — ceiling, joinery, final coats | 12 | $29.81 | $358 |
| Total | 134 | $4,387 |
Hours are this site’s assumptions for a straightforward, sound, single-storey bathroom with services staying broadly where they are — they are judgement and are stated so they can be argued with. Pay is the published median hourly rate for each trade. The pay you see here is your pay before tax. When an employer pays you, Inland Revenue (IR) collects a percentage of that income. Learn more about income tax on the IR website. Attribution: Tertiary Education Commission — Tahatū Career Navigator.
Tertiary Education Commission — Tahatū Career Navigator · 2026-07-30
The point of the model is not the number. It is that you can now ask a builder a specific question — "you have allowed 32 tiling hours, I make it closer to 45, what am I missing" — instead of a vague one. Specific questions get specific answers.
Context
Why the number your neighbour paid is no help
Stats NZ — Business price indexes (PPI and Capital Goods Price Index), March 2026 quarter · March 2026 quarter
Stats NZ — Business price indexes (PPI and Capital Goods Price Index), March 2026 quarter · March 2026 quarter
Stats NZ — Business price indexes (PPI and Capital Goods Price Index), March 2026 quarter · March 2026 quarter
Deflated by consumer inflation, whole-job residential construction has risen roughly a fifth to a quarter in a decade while a headline material fell. Construction hourly earnings rose 9.6% in real terms over the same window. That is where renovation inflation lives: labour, consenting, inspection and finance.
So a figure from a job three years ago is not a benchmark, and a figure from a different suburb is not either — the Auckland spread between local boards runs from $55,067 to $358,178 in average declared value per alteration consent. The board-by-board picture.
Questions people actually ask
Is the cheapest quote usually the worst?
Not necessarily — but the cheapest quote is very often the one that has assumed the least. Before treating a low number as a saving, check what it says about demolition and disposal, what it assumes is behind the linings, whether the consent and inspection costs are in or out, and whether there is a contingency at all. A quote with no contingency is not cheaper; it is later.
How much contingency should a renovation carry?
This is judgement, not published data. On an unopened older house, the honest planning assumption is that a real contingency is a double-digit percentage of the contract sum, and that it exists to be spent. Anyone who tells you an alteration to a 100-year-old building carries no unknowns has not opened enough walls.
Should a quote name the Licensed Building Practitioner?
Yes, if the work is restricted building work. Ask for the name and licence class, and expect a record of work at the end. It is a reasonable question, it is free to ask, and a good builder is not offended by it. What counts as restricted building work.