As New Zealanders across the country turn to renovation to add value to their biggest assets, there are some common renovation mistakes we want to help you avoid.

First things first, put down the crowbar and plan, plan, plan. Paul Riedel, from Straight Up Construction in Taupo, has one of the best reasons not to start demo without a plan. “It’s really important that you get an asbestos report before any work starts. So often a builder goes to start a job, then realises there is asbestos and work has to stop.”

It’s important you don’t try to avoid consents – remember, they’re there to protect you. As Richard Poff, of RTP Builders in Christchurch, points out “it is the owner’s responsibility to get the required permissions”, although often the builder arranges them.

“Lack of appropriate consents may lead to stalled house sales (sometimes several years later), insurance issues, and all sorts of liability issues. Even an exemption should have some paperwork completed. Just contact your local council and find what may be needed – ignorance may not end up in bliss.”

Don’t cheap out on materials or assume overseas materials are cheaper. Your materials are part of your consent, so trust your builder’s recommendations.

“Remember, when it comes to cost, your builder has been doing this for years, so their estimate will be more accurate than your own guess,” Sacha Gray, of Just Build It in Dunedin says.

“Plus, your builders sub-contractors will more likely be faster and cheaper than your mate’s mother’s cousin’s aunt. And they’ll turn up on time. Try to have your ideas all in a folder or photo file, to simplify the designer’s job. And decide on the style match – in with the old or stand out as a separate add-on.”

Mike Hayward, of Hayward Builders in Hamilton, recommends an experienced architect or designer who knows your local area. “Get them to do a site measure, so the plans are accurate to what is on site, not what is on file at council. This could also be done by your builder,” he says.

Get your NZCB builder involved from the start, working alongside you or your designer. “This helps with an on-site, practical approach, as well as helping ensure the design doesn’t outgrow the budget,” Mike says.

Speaking of budgets, Paul recommends you have a budget contingency of 10 to 15 per cent. “It is unrealistic to expect everything to be on budget or as it says on the plan.”

Richard agrees, saying “expect the unexpected”.

“Generally (without destructive investigation) you are working from an existing floor plan and finished surfaces.  An allowance needs to be in the budget for extra requirements – time and materials,” he says. He also recommends work doesn’t start until the majority of the required supplies are obtained.  “Given the current supply issues (and product ranges covered), make sure you can get everything on the list or have an alternative sorted.”

Richard says you need to work out whether you’re renovating to live in it or if it’s for resale.  “If the renovations are for living in, where possible ‘future-proof’ the work,” he says.

“Renovations can be an opportunity to upgrade all the wiring (including switchboard).  This is generally not as expensive as many think.”

Other things to consider include – putting in wider doorways (especially in high traffic areas) or cavity sliders to save space in smaller rooms; LED light fittings last longer and use less energy; over-height, back-to-the-wall toilet pans are more modern and easier to clean.

“Put in the best quality floor coverings that can be afforded. Definitely don’t think ‘cheap’ is a good option.  Good quality tapware, electrical fittings, curtains/blinds, etc, all make a difference,” Richard says. That includes windows – they can be expensive to replace, so opt for high quality from the start.

He also says to think about lights and passive heating. “Skylights or similar natural light fittings can make excellent passive light sources.  Great in hallways, above stairways, kitchens not on the sunny side of the house,” he says.

Sacha also recommends looking at insulation. “Insulate as much as you can afford now, remember it’s the minimum standard everyone is working to.”

For showers, Richard says make sure they are at least 1m x 1m.  “It’s not only older folk that may need some sort of temporary seat in the shower – even younger ones have accidents.  Try fitting a seat in a round or shower stall that is only 900mm or less square – very difficult.”

If your reno is large-scale, Paul says to think hard about whether you live on-site. “Consider whether it is realistic to live in the house during a renovation – there are factors such as dust, noise, parking and start times. Even with a small renovation, it may be better to not be living on-site.”

Richard agrees, but says there are ways around it. “If an extensive job, consider whether the renovation can be done in more than one stage.  This may enable you to utilise part of the property or assist with the cash flow.  If financed, the money-lender can reappraise the value of finished work, and then perhaps up the lending for subsequent work.”

To find an NZCB builder near you, use the Find A Builder search function on www.nzcb.nz.