Given Auckland's constricted site on a narrow isthmus would it be more appropriate to have another city as NZ's biggest urban area rather than Auckland?

If so what would be a better alternative?

It's not an island, there is no constraint

Auckland sprawls a long way outside the ithsmus. Not sure what you mean by constarints.

Auckland cant grow beyond cape reinga or wellington too easily so I guess we better find a new place to build a city.

I would think it rather obvious that Oban is about the only other alternative...

Christchurch has lots of land available :)

Auckland cant grow beyond cape reinga or wellington too easily so I guess we better find a new place to build a city.

Dosn't need too that's why the current Auckland plan has a focus on intensification. The plan is to provde higher density dwellings in certain locations and manage the sprawl.

Dosn't need too that's why the current Auckland plan has a focus on intensification. The plan is to provde higher density dwellings in certain locations and manage the sprawl.

In that case buy as much property as you can

What is the population density of Auckland ?

In that case buy as much property as you can

Got some figures to back up the sprawl = lower house prices argument?

In a fictional scenario where NZ has no cities or settlements and an area had to be chosen to create the core of the country's economy, military and culture (which I think the OP is trying to suggest) - well there's perhaps a few areas that would suit.

My first guess might be Tauranga and the area down toward Whakatane - mostly flat(ish), plenty of resources and arable land nearby, a large, natural harbour (Tauranga's estuaries, as well as between Matakana Island and the mainland). Also reasonably easy to defend, plenty of hills around the north and west to secure plus plenty of room for a large naval force.

A place with similar attributes minus a natural harbour might be the Kapiti Coast north toward Wanganui. Flat, arable, defensible, somewhat sheltered from southerly winds (kinda). Also has plenty of rivers which are of course historically important for new settlements. Also well positioned in relation to both islands.

The Canterbury plains cannot be ignored, so the Christchurch area is obviously a good choice. Mostly good weather, huge areas of flat and usable land, natural harbour, largely defended from the north and west by mountains.

Any 3 of these I reckon would be a good choice for NZ if it were to be settled only today.

I disagree - when you look hard enough at a fictional scenario, it would not have turned out to dissimilar to what we already have.

Christchurch, was chosen for those obvious reasons, and we have that city.

Tauranga, IS our biggest port- not a work of fiction.

Now Auckland is a our biggest city - (arguably) cultural and economical center for a very good reason.
Non fiction terms: The northland region was the first to be settled by the Europeans,and Auckland was favored by its more central location, more space, large harbour, and it sits on an important confluence of roads and shipping lanes, so was good for trade and close to the historical settlement of Russel and the fertile lands of the Wiakato. There IS very good reasoning why Auckland is the biggest city, so fictional cities remain fiction, because the settlers who settled here actually chose well. The only city that remains dubious in my opinion is Wellington. The site chosen for that city was actually Lower Hutt. The settlers though, were driven ashore at its present location by a large storm as they tried to fight there way into the habour.
It only succeeded because of it brilliant harbour and its central location - and it becoming the capitol for those reasons. It does have the lack of the ability to expand.

It would be great to dream of possible fictional sites for a great fictional city, but reality does check them. Spotila mentioned the Horowhenua region, north of Kapiti, south of Whanganui. Palmerston North. Would have been a far bigger city of it a still had a port. It DID have one once, at Foxton. The estuary at the river mouth was once deep and wide, but over time silted up. Palmerston North would be three time the size of it still had that port - what remains of it, is now called the Foxton loop in the old Manawatu river.

We can dream, but look hard, New Zealand is a great place, our cities ARE the best in the world - (even New Plymouth, best in 50000-70000 catagory) and a fictional city in my mind would not fit anywhere in New Zealand, because if there is such a place, a great town or city already exists there in full blown living and thriving reality, built upon by our great pioneering ancestors who I think we'd all agree, chose the the site for their new homes well.

I didn't know that about Wellington - sweet info

Got some figures to back up the sprawl = lower house prices argument?

It's quite clear that increased density increases property prices, therefore buying property in areas where the density is set to increase is a good investment. I'm not trying to have an argument for or against sprawl, I am a fan of urban sprawl and increased density, they are not mutually exclusive.