Certified Home Extensions Logo

What Should I Look For When Choosing an Extension and/or Renovation Company?

7 Things Worth Checking Before Deciding Who to Trust With Your Home

Choosing a builder for an extension or renovation is a big decision.  You’re trusting someone with your home, a significant amount of money and for several month a fairly big part of your everyday life.  While price will naturally play a part in your decision it shouldn’t be the only thing you compare.

Altering an existing home is very different from building new.  There are existing structures to work around, things that can’t always be seen until work begins and if you’re planning to stay in your home during construction, the added challenge of making everyday life work around the build.

Before you decide who to work with, here are 7 things work checking.

1. Do they actually specialise in extensions and renovations?

Building a new home and altering an existing home require quite different skills.

With an extension or renovation the builder needs to understand how the existing house has been constructed, how the new work will connect the old and what problems could be hiding behind walls, underneath floors or above ceilings.  Ask how much of their work is genuinely extensions and renovations and whether they’ve completed projects similar in scale and complexity to yours.

At Certified Home Extensions this had been our focus since 2003.  We’ve completed 237 extension and renovation projects from relatively straight forward re-models and reconfigurations through to major extensions and complex projects on character and heritage homes.  That experience helps us to recognise potential issues earlier before they become bigger and more expensive problems.


2. What is their pricing process?

Two prices can look similar on paper but have very different levels of investigation behind them. Before comparing the final number find out how each builder arrived at theirs.  Have they visited the property? Have key trades been involved? Have they looked at access, drainage, existing services and how the new work connects with the existing house?  What assumptions have been made?  What has been included or left as an allowance?

The less investigation that happens before you sign the contract, the great the potential for surprises later. 

Our own pricing process includes a detailed 154 questions checklist and a site meeting with our in-house QS Amanda, key trades such as the plumber and electrician, and our company director Alvin, a qualified builder with almost 30 years of experience. It takes more work at the beginning, but it means our pricing is based on a much deeper understanding of what is actually involved.

That experience also makes a difference much earlier in the process.  Even when we’re only providing a broad ballpark based on similar projects that we’e completed, those figure backed by years of detailed pricing and real construction experience. A ballpark based on that knowledge is likely to give you a much more useful starting point than a number based largely on square metre rates or a quick look at the plans.

We’d much rather give you a realistic indication early on before construction starts and uncover any potential challenges early, than have to explain unexpected costs and variations halfway through your build.


3. Is it clear what’s actually included?

A lower price isn’t necessarily a better price if important parts of the project have’t been included. When you’re comparing proposals look beyond the total and make sure you understand exactly what you’re getting.

Check the allowances for items you have’t selected yet, what site costs have been included, what work you’ll need to organise yourself and what has been specifically excluded.  And don’t be afraid to ask questions.

The company you choose should be able to talk you through their proposal in plain English and make sure that you’re comfortable with it before you commit.


4. How will they communicate with you once construction starts?

It’s natural to focus on the finished result when you’re choosing who to work with, but it’s just as important to think about what the months getting there will be like.  Who will be your main point of contact? How often will you hear from them? Will you know what’s happening on-site each week, and what will happen when a decision needs to be made?

At Certified Home Extensions, our clients receive a progress report every Monday afternoon, have access to their schedule and a dedicated messaging system through our project management software and always know who to contact if they have a question o rowan to talk something through. It sounds simple but knowing what’s happening and what’s coming up next make an enormous difference to your experience.

This level of communication isn’t standard across the industry so ask how it will work before you commit. If there isn’t a clear process in place from the beginning it’s easy for communication to slip once things get busy leaving you wondering what’s happening with your own project.


5. What happens when something unexpected is discovered?

Even the best planning can’t reveal everything that is happening inside an exisiting home. Once walls are opened or floors are lifted, occasionally something appears that nobody could reasonably seen beforehand.

There is only so much anyone can do to uncover every potential issue before work begins. What matters most is having a clear process in place for dealing with those situations when they arise. You should understand what’s been uncovered, what needs to happen next and any impact on your budget before any additional work goes ahead. That way, even when the unexpected happens you’re kept informed and remain part of the decision.


6. How will they make it possible for you to live at home during construction?

If you’re planning to stay in your home while work is underway, ask what the company will actually do to minimise disruption and make that manageable. Things like access, dust, temporary facilities and which parts of your home will remain usable can have a big impact on your daily life, particularly when you’r going to be living alongside the work for several months.

Around 99% of our clients continue living in their homes during construction, so it’s something we plan for from the outset. This includes thinking carefully about how the work is staged, separating construction areas from the rest of your home so that you get some respite and maintaining access to the spaces and facilities that you need.

For example, if more than one bathroom is being renovated, we can stage the work so that you are not left without one, or arrange a portable bathroom if necessary.

There is no getting around the fact that living through a an extension and/or renovation will cause some disruption but having a company who understands what it’s actually like to live onsite can make those months considerably easier.


7. Can they show you evidence not just make promises?

It’s easy for any company to say they do great work, communicate well and have plenty of experience. Before making your decision, take a little time to check for yourself.

Look through completed projects, particularly ones similar to what you’re planning, and read what previous clients have said about the experience as well as the finished result. Find out how long the company has been operating, who will actually be involved in your project and whether the people you meet at the beginning are the same people you’ll be dealing with once work gets underway.

It’s also worth asking for examples behind some of the claims being made. If they talk about accurate pricing, ask how their early estimates have compared with eventual contract prices. If communication is a big part of their service, ask what that actually looks like during construction. You should be able to get a reasonably clear picture of how the company operates before you commit.


Take your time making the decision

Choosing who to trust with your extension or renovation isn’t a decision we think you should rush. You’ll potentially be working with that company for many months, they’ll become a regular part of your everyday life and you’re trusting them with a significant investment in your home.

That’s one of the reasons we put so much emphasis on the early stages at Certified Home Extensions. Before you commit to building with us, we want you to understand what you’re getting, what it’s likely to cost, how the process will work and who you’ll be dealing with along the way.

After more than 20 years specialising in extensions and renovations, we know that a successful project isn’t just about the finished home. It’s also about feeling informed, comfortable asking questions and confident in the people guiding you through it.

If you’re starting to think about extending or renovating your home, come and have a conversation with us. We can talk through what you’d like to achieve, what might be possible and the next steps involved, so you can decide whether Certified Home Extensions feels like the right fit for you.

Get in touch

If our approach sounds like what you’re looking for, book your free 15-minute clarity call here. Zero pressure, just a no-obligation chat about what’s possible and how we can help you best.
Bombay based, covering Auckland and Hamilton regions

Get in touch

If our approach sounds like what you’re looking for, book your free 15-minute clarity call here. Zero pressure, just a no-obligation chat about what’s possible and how we can help you best.
Bombay based, covering Auckland and Hamilton regions
Whole Team w_Shadow
Certified Home Extensions Logo

Follow Us

Proud sponsors of

© 2026 House Extensions in Auckland | Certified Home Extensions
Privacy Policy