Ask for registration in writing, not verbally
If your project is a new home or a major structural alteration, ask directly about NHBRC registration and ask for it in writing before you sign anything. A contractor who is registered will send it without hesitation. One who deflects, promises to send it later, or explains why it does not apply to your job is telling you something important.
Same principle for public liability insurance and for the registration of the electrician and plumber who will actually do the work. Certificates get issued by registered people, and an unregistered installation can cause you real problems when you sell.
Visit a finished job and, better, a live one
Anyone can show you photographs. Ask to visit a site that is currently running. How a builder's live site looks on a random Tuesday tells you more than a portfolio does: whether it is tidy, whether materials are protected, whether there is anyone supervising, whether the neighbours look irritated.
Then ask for a reference from a job that went wrong. Every builder has one. What you are listening for is how it was handled, not whether it happened.
Read how the quote is written
A quote that is a single number with a one-line description is not a quote, it is an invitation to argue later. What you want is sections you can understand, a stated specification, and an explicit list of exclusions.
Exclusions are the honest part of a quote. A builder who lists what is not included is a builder who has thought about the job. A quote with no exclusions has simply moved those conversations to the middle of your build.
- Is the specification stated, or just implied?
- Are provisional sums labelled as provisional, with what settles them?
- What is explicitly excluded?
- Are payment stages tied to measured progress, or to dates?
Understand how variations will be handled
A variation is any change to the agreed scope. On a renovation there will be some, because you cannot see inside walls. The question is the process, and the answer you want is simple: nothing gets built until it is written down, priced and approved by you.
The alternative, which is where most disputes come from, is a builder who does the extra work and presents the cost at the end. By then your leverage is gone.
Be careful about the deposit
A reasonable deposit covers materials the contractor has to buy up front. An unreasonable one funds the builder's cash flow using your money, and it is the classic warning sign on jobs that end badly.
Payment should track measured work completed, at agreed stages, never far ahead of it. If you are ever significantly ahead of the value on the ground, you have lost the only leverage you had.
The cheapest quote is a data point, not an answer
When one quote is dramatically below the others, the useful question is not 'why are they cheap' but 'what have they left out'. Nine times out of ten the gap is scope, not efficiency: no allowance for the beam, no rewire, no waterproofing, no making good.
Line the quotes up against each other item by item. The gap almost always becomes visible.
Trust the site visit more than the sales visit
The person who quotes your job is not always the person who runs it. Ask who will actually be on site, how often, and who you call when something is wrong. On a small contractor that is usually the owner, which is a genuine advantage as long as they are honest about how many jobs they are running at once.
Written by Edward Whelan, Spoednik Construction · Updated August 2026
