Turnkey vs. Construction: The Head-to-Head True Cost Showdown
A quick heads-up before we dive in: This article is strictly for general informational purposes and does not constitute financial, legal, or tax advice. Every situation is entirely unique, and bank lending policies change frequently. Before making any decisions about your property journey, it is highly recommended that you seek independent advice from a qualified financial adviser.
When comparing new builds, the sticker price is almost always a trap.
You might look at a completed "Turnkey" townhouse package priced at $900,000, and then see a vacant section next door where a builder promises you can construct a similar house for a total of $850,000.
At first glance, the construction loan looks like a guaranteed way to save $50,000. But is it actually cheaper?
To answer that, you have to look past the sticker price and calculate the Holding Costs. Let's break down the true cost of both options, and use our head-to-head calculator to see which path actually leaves you better off.
Option 1: The Turnkey Reality (Cashflow Certainty)
When you buy a Turnkey property, you hand over your deposit and do absolutely nothing until the house is finished. You don't pay a single cent of mortgage interest during the build, and you just keep paying your normal rent until handover day. There is no "Overlap Penalty".
Because the developer is funding the build themselves, they are the ones paying the land mortgage, the snowballing construction interest, the council fees, and bearing the risk of material price blowouts.
The Catch: To compensate for taking on this massive financial risk, developers bake a premium into the final sticker price. That is why a Turnkey home always looks more expensive on paper—you are paying for the luxury of absolute cashflow certainty.
The Deposit Rules: Turnkey homes are much easier to finance. Banks generally require a 10% deposit. If you are a first-home buyer using the Kāinga Ora First Home Loan scheme, you may even be able to secure a Turnkey with just a 5% deposit.
Option 2: The Construction Reality (The Overlap Penalty)
When you choose a Construction Loan (Progress Payments), you cut out the developer and become the project manager. Because you aren't paying the developer's premium, the initial sticker price is lower, meaning you are essentially manufacturing instant equity.
The Catch: You take on all the holding costs. While the house is being built over 6 to 12 months, you have to pay interest on the land loan, plus the Interest-Only build payments to the builder every time a new stage is reached.
Crucially, you have to pay these mortgage costs while simultaneously paying your current rent. This is the Overlap Penalty. If your build is delayed by rain or council backlogs, those holding costs keep racking up out of your own pocket.
The Deposit Rules: Because the bank is lending against an unfinished asset, their rules are incredibly strict. To get a construction loan, you generally must have at least a 20% deposit against the land purchase, and a 10% deposit against the total project cost (Land + Build costs).
The Head-to-Head Calculator
To figure out if the instant equity of a Construction Loan outweighs the cashflow certainty of a Turnkey, you have to compare them side-by-side.
Enter your numbers below to see exactly how much cash will leave your bank account during the build phase, and what your True Final Cost will be.
Head-to-Head Calculator
Please rotate your phone sideways (landscape mode) to view the Head-to-Head Comparison.
The Conclusion: Which One Actually Wins?
As you can see in the calculator, once you factor in the holding costs—the rent overlap, the land mortgage, and the snowballing build interest—the total out-of-pocket cost of a Construction Loan often creeps incredibly close to the sticker price of a Turnkey package.
A Turnkey isn't a rip-off, and a Construction loan isn't a magic equity cheat code. They are simply two different ways of paying for the exact same holding costs. With a Turnkey, those costs are baked into the mortgage and paid off over 30 years. With a Construction loan, you pay those costs out of your own pocket in cash right now.
Ultimately, the winner comes down to what you value more: Control or Certainty.
Choose a Construction Loan if:
You want total control over the land location, the house design, and the interior finishes.
You have enough surplus income in your weekly budget to comfortably handle the Overlap Penalty (paying your rent and a mortgage at the exact same time).
You are willing to take on the risk of timeline delays to create potential instant equity.
Choose a Turnkey Package if:
You cannot afford to pay your rent and a mortgage at the same time.
You want absolute cashflow certainty and a zero-stress, hands-off process.
You are happy to trade total customisation for convenience.
Whether you decide to lock in a Turnkey package or manage your own progress payments, getting the finance structure right is the safety net beneath the entire project. We specialise in helping Kiwis navigate the complex world of new build lending. We will run the exact holding cost math on your specific situation, review your building contracts for hidden traps, and secure the best possible terms from the bank.
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