Debate over whether new housing law will make homes too expensive or turn communities into slums

There are concerns a new housing law could make homes too expensive or turn communities into slums.

The bill would allow about 100,000 three-storey homes to be built in cities without consent and there are controversial new rules about how much window and garden space they'll need. 

A dreary day in Wellington doesn't dull an architect's pride for the inner-city homes he's designed.

"Each has its own specially-designed courtyard space which directly opens off the living area," Solari Architects director James Solari says.

He's all for intensified housing - but wants quantity and quality.

"A sustainable house is one that's well-designed and one that will stand the test of time," he adds.

A law to get more homes built sooner, replacing part of the Resource Management Act, is being pushed through Parliament at pace.

Changes proposed already include requiring a 20-square-metre outdoor space like a deck or patio for all ground units, a 1m-by-1m window in every room, and a 4m-by-4m in the living room.

"We've made changes that are pragmatic," National's housing spokesperson Nicola Willis says.

Pragmatic, prettier homes will come at a higher price. Some in south Auckland fear it may price locals out of their own neighbourhoods and without the right planning, there could be too much pressure on local amenities, such as schools and shops.

"If it's done really well, it could be wonderful, if it's not done well, it could turn into a slum," warns Vicki Sykes, Mangere Housing Community Reference Group chair.

The major cause for contention is over an increase in the height to boundary limit to allow for three-storey homes. That could block neighbours' sunlight and look into their property.

"There could be a three-storey house, or three of them, 1 metre from your boundary, with a floor-to-ceiling window looking into your kids' bedroom and there's nothing you can do about it," ACT leader David Seymour says.

Seymour's dubious it'll see more homes built. But official analysis obtained by Newshub suggests it will.

At a height limit of 6 metres, Auckland would get an extra 39,000 homes over the next eight years.

The limit's been reduced to 5 metres - still double the current one and enough to allow for three-storey homes - but fewer of them.

"Marginal, it's a marginal difference," Prime Minister Jacinda Ardern says.

With a housing crisis on our doorstep, intensification is inevitable.