There are booming real estate markets for luxury apartments, boutique home renovations and at the top end of the market, but Sydney is also becoming increasingly crowded.

At the top end of the market the average size of a single detached house in Sydney is now 43,000 square metres – up almost 10 per cent in just two years.

And many of the capital’s more expensive homes are getting a race to meet the demand.

The national trend is particularly pronounced in inner-city suburbs where new units are being built at a rapid rate.

The average size of a detached house in Sydney has doubled in two years, to 46,000 square metres

Wonders Bay is one of the hot spots for private rental homes, with prices beginning to edge up

Wonders Bay is one of the hot spots for private rental homes, with prices beginning to edge up.

It is an area with heated urban infrastructure with a population of 639,000 people, four times the size of Penrith – with more than 100,000 foreigners living in the area.

As well as a growing workforce with little need for luxury accommodation, North Sydney is also rapidly becoming more desirable.

Twelve private apartment towers are set to open in the CBD over the next decade, sparking concerns about Sydney’s growing popularity.

Three towers should start to open this year, including the high end Parkview apartments at the northwest corner of George and Water Streets, which will cost $18 million.

Gold Coast is also becoming a popular destination for foreign buyers, particularly those from Asia.

There have been nearly 40,000 new homes sold in the CBD in the past two years, compared to 35,000 two years ago.

At the top end of the market, more expensive apartments are going up at a faster rate than ever before

If the demand keeps going up, Sydney will soon become the largest city in the world with its housing stock

To understand the market, consider comparing Perth with Sydney to say the US and then compare Melbourne with Australia.

Perth has a population of just over 2.4 million, Melbourne has an enormous population of over 29 million.

You can see the difference between the two metropolitan capitals, with Perth’s population jumping from 14,000 five years ago to 18,800 today and the Melbourne’s jumping from 6.9 million five years ago to 13.4 million today.

However, Sydney and Melbourne are not stopping there.

According to Macquarie, the average price of a Sydney home has ballooned by nearly 20 per cent in the past two years to $402,200.

The average size of a single detached house in Sydney has doubled in two years, to 46,000 square metres

The national trend is particularly pronounced in inner-city suburbs where new units are being built at a rapid rate

Both cities are experiencing a rapid build up of housing stock, with Sydney and Melbourne currently in full swing.

However, because they have such large populations, growth is occurring almost in stages.

Foreign buyers are already flooding into Sydney, according to Macquarie, with the number of investment property in Sydney increasing by more than 11 per cent over the past five years.

A survey out this week by Melbourne-based Domain found 19 per cent of Melbourne-based brokers planned to invest in a new apartment building within the next year.

The percentage jump in Melbourne property investment was 2.3 per cent higher than in Sydney, with 36 per cent of 50- to 79-year-olds planning to invest.