Radical plan cuts noise for apartment-dwellers

By WAYNE THOMPSON

Auckland's apartment dwellers are being promised a better night's sleep in radical proposals for beefing up the sound insulation in units.

The Building Industry Authority is suggesting changes to the building code to increase levels of noise control in multi-unit developments.

The changes - aimed at reducing maximum noise levels from 55 to 50 decibels - will safeguard apartment dwellers from illness or loss of amenity in areas near airports, motorways or noisy city night-life.

Key changes to the code are based on standards of 18 European countries and the United States.

In Auckland, research has consistently shown that noise is a problem for residents of multi-unit dwellings, says the Auckland Regional Growth Forum.

Higher-density living for the cities' town centres are a key to the region's master plan for preparing for two million people by 2050. Four out of 10 new dwellings are either apartments, townhouses or flats.

"It is essential that high levels of sound insulation are achieved," said forum adviser Brenna Waghorn.

"More people will be living in areas that are noisier, within vibrant 24-hour town centres with a range of activities, near night-time entertainment and close to train stations and major roads."

The BIA is calling for submissions and the forum is preparing one which supports proposed higher standards, based on consumer research across the region.

The apartment building industry agrees with the need to raise standards but is unhappy with technical aspects of the key code changes and how they can be put into practice.

The convener of an industry meeting about the proposals, Winstone Wallboard's David Scott, said the present noise control provisions were too low.

But the proposals were out of step with the minimum requirements of the rest of the world.

Rather than try to give an acceptable level of occupant satisfaction, the proposals went further to provide excellence. But they would result in substantial added costs to projects.

A big bone of contention is the requirement for "on-site testing" to confirm compliance. The idea is that as soon as the first units in a building are finished they will be tested to see how the building as a whole copes with nuisance noise such as the boom-boom of a neighbour's stereo.

Winstone Wallboards says a better system would verify compliance before the building went up, because it was costly to put right structures with acoustic defects.

The industry shares the forum's concern that acoustic standards must not harm the other highly desirable values of a building, such as light and ventilation.

A further criticism is the uncertainty about whether the benefits outweigh the costs of improving sound insulation by 5 decibels.

The BIA said Rider Hunt consultants estimated the total increase in building costs for an apartment of 40sq m to 80sq m.

The consultant's calculations suggested the increased cost would be $11,000 (a 12 per cent increase) for timber construction and $12,000 (13 per cent) for concrete construction.

Firecone consultants found the likely benefits would equal only two-thirds of the expected costs - a net cost of $3650 an apartment.

The Herald understands that property consultants DTZ calculated the city has 12,700 units and 3200 units being planned.

Martin Dunn, of City Sales, said he was surprised that noise generated inside a building was a problem for apartment dwellers. In 13 years of selling central-city apartments he had never had a complaint.

The BIA will take submissions until August 16.