Even expensive houses flunk fitness test

Half of all homes may have building defects and maintenance shortcomings, according to a Branz survey of the nation's housing stock.

Before Branz inspectors pointed out shaky foundations, rot-causing ventilation lapses, rising damp in the walls and dangerous decks, 80 per cent of the 565 home-owners in the random survey thought their homes were in good or excellent condition.

But inspectors found fault with half of the houses surveyed.

Owners thought their homes were in top condition because they were expensive. The survey also found that houses with long-term owners tended to be in worse condition.

"Perhaps it is a case of owners selling before conditions deteriorate too far, or the urge to renovate and improve one's house wearing off with time," said a spokesman for Branz, a building research and testing consultancy.

However, inspectors were impressed by those with the enthusiasm and money to renovate homes built before World War II.

After repairs and upgrades, old homes were in the same condition as those 50 years younger and their value was rising with age.

The housing stock improved by 10 per cent since the last survey in 1999. This was thanks to the high level of building activity in both new homes and renovation of older houses.

In 1999, Branz found 70 per cent were built before 1970 but this time the figure was 55 per cent.

Many of the house defects spotted in previous surveys persist.

Newest houses were the biggest offenders in having inadequate clearance of wall claddings above adjacent ground. This was blamed on trying to get "indoor-outdoor flow" at the expense of good building practice.

"Those must have been '90s houses," said Registered Master Builders Federation chief executive Pieter Burghout. "Today this happens a lot less."

Since the controls arising from the leaky homes problem, owners, designers and builders placed structural integrity before indoor-outdoor flow, he said. Councils were more careful, too, about what passed their building consents process.

The Branz survey was also concerned about faults under houses. Many had less than half the subfloor ventilation area required by building standards.

This could lead to timber decay, fungal growth, borer attack, general dampness and corrosion of metal that fastens the house timber to the concrete piles.

That is if the fasteners were not already in a poor or serious condition or, as was particularly the case in Auckland, missing.

Most bathrooms and kitchens were poorly ventilated to clear steam, which damaged materials and finishes.

Outdoors, about 70 per cent of deck barriers flunked the building code and half of the hot-water cylinders and header tanks did not have restraints to stop them crashing down in an earthquake.

On the energy-wasting front, the survey noted ceiling insulation was poor or unsafe in one in 10 homes and that a quarter of hot-water cylinders were of the old inefficient type.

Energy Efficiency and Conservation Authority spokesman Robert Tromop said 6 per cent of homes surveyed had no insulation despite grants being available for low-income home owners to get it.

About 30 per cent of homes had either partial insulation or insulation that was too thin by today's standards.

Mr Tromop said people could save $100 a year on their power bill if they replaced the inefficient and unwrapped water cylinders installed before 1976.