Now that the Auckland property boom has (at least briefly) come off the boil, people can analyse what has happened.
A housing boom follows a ripple effect. The first suburbs to rise in value tend to be near the central business district. Over time, price rises move further out like ripples from a stone thrown into a pond. Pretty much every suburb goes up over time. Perhaps an astute buyer can guess which suburbs are likely to go up next, although trends are easier to spot with hindsight.
According to QV New Zealand figures, back in 1989, the average price for a West Auckland house was a bargain at $124,286 and in central Auckland at $145,330. The economy was still suffering from the effects of the 1987 sharemarket crash. Inflation, the Reserve Bank says -- averaging 2.5 per cent a year since 1990 -- trimmed that capital gain slightly.
Auckland's central suburbs, such as Ponsonby or Grey Lynn, are now comparatively more expensive than hitherto. According to QV figures, central Auckland houses prices have, on average, risen by five times since 1989, Waitakere is up by 4.5 times and the North Shore by a bit less, 4.3 times.
Remuera is an interesting case -- generally regarded as smoothly rising in value. Remuera houses are always worth more than Ponsonby. Back in 2000, a Ponsonby house seemed a bargain at $338,000, while a Remuera property averaging $487,700 was a lot of money.
The average Remuera property is now worth nearly $1.8 million, while the average Ponsonby home is worth $1.54 million. This gives the impression Ponsonby has risen a bit more over the past 15 years.
ASB chief economist Nick Tuffley explains how the boom has worked. Many home buyers want to live close to town, especially if they work there. Many also want to be near good schools, kindergartens, a beach and have room outside.
Buyers look for somewhere that "ticks the boxes" and that they can afford. Unless they get carried away at an auction, buyers behave rationally. And it is surprising what people will pay to cut the daily commute.
"Time can be precious," Tuffley says. "People need to live somewhere. Some may want to live in the outskirts of Auckland, but I would wager the bulk would prefer to live near the major centres."
Suburbs that meet all these criteria include Orakei, Parnell and Kohimarama, all near Auckland's waterfront drive. On the western side of town, there is the strip from Herne Bay to Pt Chevalier. On the North Shore, Takapuna is obviously the top beach nearest to town, although the commute is delayed by the harbour bridge.
Tuffley describes Auckland property as "a cone", its narrow top representing the smaller number of inner-city suburbs, while the suburbs further down the cone, or further away from town, are in increasingly larger supply, always worth less and taking longer to go up in value.
Gentrification is a process that changes how people feel about a suburb and how much they will pay. People renovate houses, put in flash kitchens and generally make them better. In Tuffley's view, the classic case was Ponsonby, and the gentrification process has slowly spread further out.
Ponsonby became fashionable during the 1970s, then Grey Lynn, Westmere, Kingsland and, more recently, Sandringham. All are former "working class", all now "million dollar plus" areas. It appears gentrification has also helped areas such as Ponsonby increase in value, as it has scrubbed itself up.
So why has West Auckland gone up more than the North Shore? It is only a theory, but Tuffley reckons there has been more building on the shore than out west -- supply is greater.
QV national spokeswoman Andrea Rush says the new infrastructure -- a new "hub" including malls, offices and motorways, makes the area a better place to live than hitherto. "The west is coming of age," she says.
New roads and rail lines can also affect a suburb's desirability. Auckland is in the middle of a multibillion-dollar boom in investment in transport infrastructure. The central rail loop will make it easier to travel to the CBD from the west and south, as the North Shore bus lane has done.
So as Auckland grows, people change expectations and see the point in living within a walk or short bus ride from a train station. QV's view, says Rush, is that the improved train system has added to rises of property values in New Lynn.
When tunnel machine "Alice" completes her work at Waterview, perhaps motorway gridlock will lessen, making the outer suburbs easier to get to, until the new motorway gets full of cars. Intensification will also change things. As land gets more valuable near town, it makes sense for developers to build apartments or townhouses on rezoned sites. This is inevitable in any large city, where people accept that good quality inner-city apartments are close to both work and city life. Auckland has good-quality apartments, as well as its share of leaky homes and soulless high rise.
Many people accept apartment living. It may suit their busy lifestyle, while others prefer to relax in a garden. But a suburb with more apartments will average out at less than it would have had it been villas and leafy streets.
Lately the QV figures show the price growth has been stronger in the outer suburbs in the south, as the boom ripples outward. The big question is "What happens next?" The ripples have already hit the edge of the pond.
The drivers for property boom have included low interest rates, economic growth and migration from smaller towns and overseas.
Auckland's population and economic growth rate is about 3 per cent a year, according to figures from the Bank of New Zealand and council tourism and economic arm Ateed.
On the opposite side, the rural economy is slowing. In the short term, this will encourage some people to migrate to Auckland, looking for jobs and houses. In the longer term, while the overnight cash rate may continue to go down, so will taxes from the dairy sector.
But Auckland's economy seems resilient, and so long as there are relatively more jobs than in the regions, people will continue to migrate, or stay. And most of those people eventually want to buy a house.
In the past, the property booms generally flattened off once they have run their course.
The market then tends to sit there for a few years, and the suburbs retain a similar or slightly changed relativity to how they were at the beginning of the boom.
The booms have also been curtailed abruptly as a result of economic shock, including the global financial crisis of 2007/8 and the 1987 share market crash. During these situations in particular, the real or post-inflation value of homes does fall, but probably less so in the most sought-after suburbs near town.