Brian Rudman: Noise rules could drive you crazy

Studying the plans for limiting noise in the expanded city can be depressing. Photo / Greg Bowker

Unless politicians wake up, city's brave new world could be even noisier than it is now

While the good burghers of St Heliers and Devonport froth at the idea of being absorbed into Mayor Len Brown's compact city, my worries are more about the detail.

What controls will be imposed to ensure the good design of the new terrace housing and apartment blocks? How much green space will be required? What noise controls will be set in place?

These are prerequisites in the transformation of old Auckland into the world's most liveable city. So far I haven't had much luck pinpointing the first two. I'm just hoping they're better than the proposed new noise regulations.

Two months back, when the first version of the draft unitary plan now being debated was unveiled, I had a quick flick through and wrote that the best that could be said about the proposed noise limits was that they were tougher than the existing Auckland City limits. Rereading them, I discover I was wrong. They're not better, they permit a noisier environment, and unless the politicians wake up, they're going to preside over a potentially noisier residential Auckland than we have now. That's within the old Auckland City boundaries at least; I haven't compared the noise regulations of the other legacy councils.

How depressing is that. When you're planning to pack tens of thousands of new residents into existing suburbs, living cheek by jowl with one another, an obvious first step would surely have been to ensure such universal irritants as neighbourhood noise were nipped in the bud. That means ensuring the liveability of the new intensive suburbs by limiting the irritating whirrings and droning from the heat pumps and spa pool motors for one.

The draft plan acknowledges as much in its first two principles:

"1. Set noise standards to reflect the zone's function and permitted activities, recognising the potential adverse effects noise generation may have on more sensitive adjacent zones.

2. Minimise, where practical, noise at its source to mitigate adverse effects on adjacent properties."

But having said this, the unitary plan then sets the maximum noise levels to be permitted in residential Auckland at the upper-most limits of the range set out in the New Zealand Standards.

The NZ Standards' recommended range of noise limits for residentially zoned sites is between 45-55 dBA Leq during the day and 35-45 dBA Leq at night, with a maximum burst of sound of 70-75 dBA. To explain. Noise is measured in decibels (dBA). Leq stands for "equivalent continuous level" and represents the "averaging" of a continuous, but variable level of sound. Instead of aiming for the quietest possible standard, the designers of the world's most liveable city have taken the easy way out.

For any non-residential activity measured at the boundary of a residential property, the dBA Leq from 7am to 10pm can be 55dBA, falling to 45dBA at night and Sundays, with a maximum of 75dBA. For noise created within residential zones, the maximum level allowed at the next door boundary is 5dBA less all round.

The old Auckland City used a slightly different system for measuring decibel levels which I'll leave for another time. But a leading acoustician tells me the proposed 55/45 dBA upper maximum referred to in the first example is 6 to 8 decibels louder than the present Auckland City maximum, and the new 50/40 noise cap, 3 decibels louder.

The new rules have a varied assortment of upper noise limits for everything from bird scarers to wind turbines. They even require that, where a bedroom window in a mixed zone can't be left open at night because the noise outside is more than 35 dBA, the landlord must supply an air-conditioning system providing 15 air changes an hour.

It does seem odd that 35dBA is considered too noisy for sleeping in a mixed zone - which includes commercial activity - yet a higher cap is acceptable in the fully residential zones.

As someone who, in the past, has been driven crazy by the night-and-day whine and drone of a commercial refrigerator condenser, I know how easily unwanted noise can make one's environment unliveable.

In creating the brave new world of compact Auckland, we should be aiming for best possible practice. At the very worst we should at least be trying to match existing standards, not going for something even worse.