Building a home is an exciting milestone, but it can also be one of the biggest financial commitments you'll ever make. Before you talk to the bank about building a home, it's worth understanding how construction lending works, where costs commonly blow out, and why preparation matters more than most people realise.
Building a Home Starts Long Before Construction
When most people think about building a home, they picture choosing floor plans, finishes and landscaping. In reality, the financial planning starts well before the first shovel goes into the ground.
For many homeowners, the process begins with an existing property and mortgage. If you’re planning to build, you’ll often need to use the equity in your current home to purchase land before construction even begins.
From there, many people will need to sell their existing home and either rent or stay with family while the build is underway. Trying to keep paying your current mortgage while also funding a construction project can quickly become unaffordable.
Before making any decisions, it’s important to have the entire plan approved by the bank, rather than buying land first and hoping the rest will fall into place
Building a Home Usually Costs More Than You Expect
One of the biggest misconceptions about building a home is focusing only on the advertised build price.
Using average figures discussed in the episode, building costs alone can sit around $600,000 for a typical standalone New Zealand home. However, that doesn’t include the land itself.
There are also plenty of additional costs that are easy to overlook, including:
- Driveways
- Fencing
- Landscaping
- Council costs
- Site works
- Earthworks
Earthworks is one of the most common areas where projects exceed budget. Until excavation begins, nobody knows exactly what lies beneath the ground, which is why many contractors won’t offer fixed pricing for this stage.
A geotechnical report can help reduce some of this uncertainty before construction begins.
Small Upgrades Can Add Up Quickly
Even when the build itself stays on track, many budgets blow out because of decisions made during construction.
What starts as standard finishes can quickly become upgraded fixtures, premium materials or higher-end specifications.
Individually these changes may seem small, but multiple upgrades throughout the build can significantly increase the final cost. On top of that, any variations made after contracts have been signed generally attract additional builder margins.
Having a realistic budget before construction starts makes it easier to separate genuine priorities from expensive impulse decisions.
Choosing the Cheapest Builder Can Be Risky
Price is important, but it shouldn’t be the only factor when choosing a builder.
The episode shares an example of accepting a quote that was roughly half the price of the other builders. While it initially appeared to be a bargain, it ultimately resulted in disputes over additional charges, work stopping unexpectedly, and eventually ending up in the Disputes Tribunal.
If one quote sits well below every other price you’ve received, it’s worth understanding why before signing a contract.
Getting multiple quotes and carefully comparing what’s included can help avoid expensive surprises later.
How Construction Loans Actually Work
Construction lending works differently from a standard home loan.
Rather than receiving all of the money upfront, the bank releases funds in stages as the build progresses.
For example, payments may be made after milestones such as:
- Foundations being completed
- Framing being erected
- Roofing being installed
- Other agreed construction stages
Each drawdown is matched against the original payment schedule provided to the bank.
If an invoice exceeds what was originally approved, the bank will generally stop and ask questions before releasing additional funds. They’ll want to understand why costs have increased, how the project is tracking, and whether the remaining budget is still achievable.
This staged approach helps both the bank and the homeowner keep the project under control.
Why Banks Build in a Cost Buffer
Construction rarely goes exactly to plan.
Delays, unexpected ground conditions and rising material costs can all increase the final price.
Because of this, lenders often assess borrowers against a higher budget than the quoted construction cost. Rather than approving only the exact amount required, they may ensure borrowers could still afford the project if costs increased significantly.
That doesn’t mean unlimited funding is available, but it does provide some protection if unexpected expenses arise during the build.
Be Realistic About Timeframes
Another common mistake is underestimating how long a build will take.
While many people hope to be in their new home within six months, the discussion suggests that around a year is often a more realistic expectation.
Longer build times can increase costs through:
- Higher financing costs
- Additional labour
- Extended living expenses while renting
- Ongoing mortgage repayments
Planning for a longer timeframe can help reduce financial stress if delays occur.
Building Isn't Always a Horror Story
Shows like Grand Designs tend to focus on projects that go spectacularly wrong, but they aren’t representative of every build.
Thousands of homes are completed successfully every year without major issues.
For people who can comfortably afford the project, have realistic expectations and carefully plan their finances, building a home can still be a rewarding way to create a property that suits their long-term lifestyle.
While the process itself can be stressful, many homeowners ultimately value the finished result.
Key Takeaways
- Building a home requires financial planning well before construction begins.
- The advertised build cost doesn’t include land or many additional site costs.
- Earthworks are one of the most common reasons budgets increase.
- Small upgrades throughout the build can have a significant impact on the final cost.
- Don’t choose a builder based solely on the cheapest quote.
- Construction loans release funds in stages as milestones are completed.
- Banks closely monitor cost overruns and may request explanations before approving additional funding.
- Allow for delays and unexpected expenses when budgeting.
- Careful planning before talking to the bank can make the entire building process much smoother.
Next Steps
Thinking about building a home? Speak with the Lighthouse Mortgages team before you talk to the bank to understand your borrowing options, construction lending and how to structure your build with confidence.
If you’d like to watch more, check out these other episodes below.
For a no obligation discussion to see how we can help you on the path to wealth, please contact us.
Disclaimer:
The information in this article is general information only, is provided free of charge and does not constitute professional advice. We try to keep the information up to date. However, to the fullest extent permitted by law, we disclaim all warranties, express or implied, in relation to this article – including (without limitation) warranties as to accuracy, completeness and fitness for any particular purpose. Please seek independent advice before acting on any information in this article.
