cost plus or fixed price?
One of the first real decisions in any build is how you'll pay for it. At Dufty+Co we offer two options: cost plus (also called charge-up) and fixed price. Neither is better than the other. They suit different projects and different people.
Here's how each one works, so you can go into that conversation knowing what to ask.
Cost plus (charge-up)
With a cost plus contract, you pay the actual cost of labour, materials and subcontractors as the build goes, plus an agreed margin. You get an estimate at the start, but the final figure is whatever the job ends up costing.
Why people choose it
Room to change your mind. If you want to change a layout, upgrade a finish or add something once you can see the space, it's easier to do.
You only pay for what's used. There's no contingency built in for risks that may never come up.
Full visibility. You can see the invoices and costs behind every part of the build.
A more collaborative process. Decisions get made together as the project moves along.
What to weigh up
The final cost isn't locked in. Changes, price rises or surprises on site go straight onto the total.
It needs more of your time. You'll usually make more decisions along the way and keep a closer eye on the budget.
Trust matters. It works best when you have regular, clear updates from your builder. That's why we report costs openly throughout the build.
Best for: renovations, architectural or one-off homes, and projects where some details will be decided once work starts.
Fixed price
With a fixed price contract, we agree on the full cost of the build before work starts. As long as the scope doesn't change, that's the price you pay.
Why people choose it
Budget certainty. You know the number from day one, which makes it easier to plan everything else.
Less to manage. Once the contract is signed, you can step back and let us run the job.
Easier to finance. Many banks prefer a fixed price when they approve lending for a build.
What to weigh up
Changes cost more. Anything outside the agreed scope becomes a variation and is priced separately.
It includes a contingency. A fixed price has to cover risks that may never happen, so it can come in higher than a cost plus job would.
More work up front. Plans, specs and selections need to be finalised before we can price accurately.
Best for: new builds, transportable homes and granny flats with a clear design, or anyone who wants a firm budget from the start.
Which is right for you?
It mostly comes down to what matters more to you: certainty or flexibility.
If you want a clear budget and a simpler process, fixed price is usually the better fit. If you'd like room to adjust as the build takes shape and you're happy to stay involved, cost plus gives you that freedom.
Whichever way you go, you'll get the same things from us: honest pricing, regular updates, and a clear explanation of any variation before it happens.
Talk it through with us
Not sure which option suits your project? We're happy to go through your plans and give you a straight answer on which pricing model makes sense.
Call Dan on 027 391 6157, email dan@duftybuilders.co.nz, or send us a message.
