Shows such as TV3's The Block are fuelling people's desire for DIY, with a buoyant property market - and the Bay of Plenty is no exception.
But many renovators go blindly into projects unaware of potential pitfalls.
In their DIY history, spanning Auckland, Australia and the Mount, Ms Bui and Mr Mundy have encountered many nasty surprises and warn others to seek professional advice before undertaking major projects.
Among their worst discoveries have been badly rotting floors in two houses where kitchens and bathrooms were renovated by previous owners.
In one toilet, the floor had vanished altogether.
"Someone had done a half-hearted plumbing job," said Mr Mundy. "It was being held up by the rafters."
The 49-year-old said the biggest pitfall of DIY was 'taking for granted that the person who has renovated before you has known what they're doing'.
He said many old houses were renovations piled on top of renovations and he advised anyone contemplating a do-up to seek advice from a registered builder to find out exactly what was involved.
Ms Bui said, "You never know what's behind a wall."
The couple said it was also important to know your limitations. Because of their busy lives as company directors and parents to 6-year-old Finn, they did not have time for major structural work now, and left plumbing and electrical jobs to the professionals.
"If you're not certified, you're buggered," said Mr Mundy.
His sister-in-law, Lara Bui, who lives in Matua and has also renovated several homes, said it was crucial to consult the council for information.
"You don't want someone coming after you 10 years later. We always look at a property with a view to the future."
Sonia Gilbert, who is renovating a house in Otumoetai, got all work certified and recorded on her property file as 'insurance for the future'.
Tania Bui and Dennis Mundy say despite the pitfalls, renovation has saved them plenty of money over the years and will always remain a passion.
"It's nice to come home to a house you've created," Mr Mundy said. "It adds to the quality of life."
DIY MUSTSExperts say it is crucial to know whether consent is required for DIY projects.
Frans Boucken, who runs Building Surveying Services and is a building inspector for the Tauranga City Council, said he regularly sees work done without consents or permits.
"When people sell their home, that's when it becomes exposed. If work has been done poorly, a lot of work may be required to get it certified."
He said people needed to consult a builder or building surveyor for major DIY projects because even if a consent was not required, the work had to comply with the Building Code.
PlaceMakers Mount Maunganui branch operator Matt Orr said changes to the law meant some structural alterations now required a 10-year warranty, presenting a potential minefield for inexperienced DIYers.
Bunnings Mount Maunganui store manager Tony Hoyle said health and safety were top priority for home renovators. He listed adequate ventilation when painting, a dusk mask when sanding, safety boots when landscaping and 'the right tools for the job' as crucial.
