Based on the number of views per rental listing on the realestate.com.au website, PropTrack's exclusive data reveals the suburbs that have seen the biggest increase in demand over the past two summers, with Sydney's south-west, Parramatta and the inner west topping the list.

The south-western suburb of Wylie Park has seen a massive 167 per cent increase in viewings over the past two summers. This is followed by the Inner West suburb of Ashfield, and the South West suburbs of East Hill, Arawa, Lakemba and Campsie, where demand has more than doubled. Carramar, Harris Park and Silverwater in the Parramatta region also made the top ten.

PropTrack senior economist Angus Moore says the rental market has gone from relatively weak to very tight. He noted, "If you look back to last summer, there was more supply and relative weakness in the rental market. But now, the rental market is very tight across Sydney. The rental market in the south-west, inner west and Parramatta belt has seen a significant rise as has the rest of the region."

Tony Rumanus, director of Ray White Bankstown, attributes the increase in demand in Sydney's south-west to the area's affordability and demographics.

According to PropTrack, the median weekly rent for a unit in Wylie Park is A$450 and the median weekly rent for a residence is A$650. Rumanus noted, "Affordability is a major factor, but it all comes back to supply and demand. We recently rented a three-bedroom unit for just over A$500 per week. It usually takes 2-3 weeks to rent out, but our turnaround was much quicker." He added that the suburbs of Wiley Park and Lakemba lacked large new developments, while older red-brick flats offered an affordable alternative.

Mr Moore said vacancy rates were one of the reasons for the continued growth in demand. At the end of 2021, Sydney's vacancy rate is just under 2.5 per cent, and by the end of 2022, it is around 1.5 per cent," he said. As we move into the summer months, the vacancy rate drops to a very tight 1.1 per cent. We also observe rents rising in all areas of Sydney."

While December is usually a quiet period for the rental market, things usually heat up in January as people look to move and start afresh. Currently, the Northern Beaches area has the tightest rental market.

Mr Moore said, "We're really splitting hairs, the rental market is tight across Sydney and even in the Hills area the vacancy rate is only 1.5 per cent. We're seeing a very fast pace of rentals at the moment. Across Sydney, properties are being rented for around 20 days, down from around 30 days before the outbreak, highlighting the need for organisation and quick action."

Finder's RBA Cash Rate Survey experts have predicted that rental prices will continue to rise across Australia through to the end of 2024, and Finder's Head of Consumer Research, Graham Cook, said their Consumer Sentiment Tracker survey shows that 42 per cent of renters are currently struggling to pay their rent.

Cook noted, "Much of the discussion about interest rate rises has centred on homeowners, but renters are actually more affected as they deal with rising rents and speculative landlords. Further rent rises are not good news for those struggling."