A house on Tennyson Crescent, Forrest, has been sold for $1.335 million. It's the city's first million-dollar house.

It was the symbolic opening of the floodgates. Within a few months, there were at least three more million-dollar sales in Red Hill.

Today, $1 million sales are a regular occurrence and almost every suburb has at least one.

They are no longer just for the mega-rich, but increasingly sold to more (upper) middle-class families. Families like James Giggacher and wife Carla Morgan, who bought a four-bedroom family home in Hughes for $1.105 million recently, a purchase price Mr Giggacher said was "pretty average" in the market.

"I think more and more Australian families are just finding that's what they have to pay for a house, particularly for a long-term family home," Mr Giggacher said.

"That's just the characteristics of Australia at the moment, it just keeps increasing."

More than 600 Canberra homes, including townhouses, sold for more than $1 million in the 12 months to the end of February.

And there are plenty of suburbs where the median price is seven figures - that is, more homes are sold for $1 million than less than that level.

Forrest - which is now sitting just shy of $3 million - hit the mark in 2002, and it remains the epicentre of the city's most expensive property.

While these "million-dollar suburbs" began spreading out from there relatively slowly, it's been gathering pace in recent years.

After Forrest, it took five years for the next suburbs to join the $1 million median club: Reid in April 2007 and O'Malley in July. Then it was Yarralumla a year later, followed by Griffith, Kingston and Red Hill in 2009.

In 2014, Turner cracked the $1 million mark, followed by Campbell and Deakin in 2015, and last year Braddon joined the club in May. The most recent suburb to hit the million is O'Connor in August 2017.

According to Domain data, all but one of the $1 million median-price suburbs are in the older and more established suburbs in the inner north and inner south. Domain data scientist Nicola Powell said O'Malley, in the Woden Valley, was the only suburb outside the centre - for now anyway.

"Like with any city, you'll see the higher price-point market is near the CBD," she said.

"The largest blocks we see around Canberra are located in the inner north and south.

"A large block clearly commands a heftier price tag, and when compared to some of our newer suburbs that are now offering smaller blocks in order to create an affordable market offering. For some buyers, the large established suburbs are highly sought after."

The suburbs were also renowned for being tightly held.

"Campbell is a great example that has a median price now of just over $1.2 million. All you've got to do is drive around the suburb and have a look at how much that suburb has changed, even in the last 12 to18 months," she said.

"There's a lot of knock-down rebuilds occurring, there's a lot of renovation, so ... it overall improves the area and improves the price point."

Mr Giggacher, who moved to Melbourne last year for work but quickly returned, said Canberra was more affordable than Sydney and Melbourne.

"When you look in Melbourne you're looking at an average house price of maybe $1 million but that's not even within 20-25km of the city centre, so you're looking at long commute times, whereas here if you're paying for something similar you can ride or even run to work," he said.

"For us, we weren't looking to buy a $1 million home; what we were looking for was a home in a great location with schools and a great lifestyle and that's what we've found with Hughes."

While Hughes hasn't hit the million-dollar-median mark just yet, it's likely to be one of the next.

Chris Wilson, of Cream Residential, said suburbs like Hughes, Curtin and Garran were seeing strong demand from families.

"Part of the reason is that the schools in the area are in high demand and that it is seen to be better value for money than what you are paying for a home in Deakin or Yarralumla, which is only a few minutes away as the prices there are very high in those areas too," Mr Wilson said.

Dr Powell said even though Canberra prices were growing, it was still "relatively affordable" compared with other cities such as Sydney.

But that in itself is also a sign of the challenges that can face those on lower incomes who are trying to buy a place to live.

In February, in the relatively modest Belconnen suburb of Evatt, a house on Callaghan Street sold for $1.17 million. It was the suburb's second sale over the $1 million mark. Evatt's median price is $551,000.

You can still get your hands on homes that are below $500,000. The lowest median in 2017 for Canberra was $426,500 in Belconnen followed by Oaks Estate, Charnwood, MacGregor, and Ngunnawal. Belconnen has fewer houses which would drive the median house price down.

As expensive as that is, it remains well off the levels of the top of the market.

After Forrest, Griffith is Canberra's second-most-expensive suburb, with a median price of $1.440 million, followed by Yarralumla ($1.422 million), Reid ($1.421), Red Hill ($1.4 million) and O'Malley ($1.387 million).

Terraces and townhouses are included in Domain's house-price data, which results in prices slightly lower than some other analyses.

Dr Powell predicts Woden suburbs like Garran and Hughes will be next to join the club, along with Ainslie.

"There are houses in Ainslie that have sold over $1 million which you'll easily find," she said.

"But there's also some homes that have sold for below a million dollars, which is why the median house price is $903,000."

And they won't be the last homes to breach that mark.