To take advantage of the booming Sydney housing market, it was said that a H&M Home range may also be in its 5000 square metre Pitt St Mall Sydney store, in the same way that it offers in its GPO Bourke Street Mall, Melbourne.

Offering homewares will also be the order at the two retailers' stores planned for AMP Shopping Centre's Macquarie Centre.

Signature homewares is one of the higher-margin products for a retailer and the growth in Sydney's residential sector has seen a corresponding rise in demand for new furniture, including crockery and accessories, to sit in the new kitchens.

This comes as the next titan of global fashion arrives, Forever 21, at Investa's 400 George Street.

Greg Long, general manager Sydney CBD portfolio at Investa, said the retail strategy has been focused on repositioning the Sydney Arcade at 400 George Street to take advantage of strong demand from top quality brands that require high-impact retail spaces in super prime locations.

Investa Office has finalised a 10-year lease over 2741 square metres prime Pitt Street Mall space to the international fashion retailer Forever 21 at its Sydney Arcade, to replace the Adidas and Glue tenants.

Simon Hemphill, head of NSW research at Savills, said shop rents around the Pitt Street Mall average about $7300 per square metre per annum, but climb to as much as $10,000 per square metre per annum for prime street front locations.

"Even though they are already among the world's most expensive, the renewed competition for prime locations spurred by the new arrival brands could see rents climb even further," Mr Hemphill said.

Alex Alamsyah, senior director of retail leasing, at Knight Frank, who advised on the lease for Forever 21, (F21) said in the fashion world, H&M and Forever 21 are rivals in a sense; one surpasses the other in some countries and vice versa.

"It took a  four and five-year search for H&M and F21 respectively, to find a location of the calibre required to anchor these brands in Sydney," Mr Alamsyah said.

"The Wall Street Journal said fast-fashion chains such as F21 and H&M are eating the lunch of traditional teen retailers like Abercrombie & Fitch, American Eagle Outfitters and Aéropostale (also known as The 3As); to learn more about where teens are shopping and why, The Wall Street Journal went on an extended tour of the mall with two groups of committed shoppers, and it is clear why fast fashion is winning."

Mr Alamsyah said the Battle of the brands, 'Round One' in 2011/12 was Zara vs Topshop. Both have made their mark in the retail sector.

"We presume the winner is Zara, based on sales per square metre per annum," he said.

"The next Battle of the brands, 'Round Two' in 2014/15 will be H&M vs F21; it is too soon to say who will win this one, but time will surely tell and teenage shoppers and the general public will have so much choice for fast fashion, making it a very exciting time in retail."

Last week, Stockland/Investa announced a 5000 square metre H&M deal in Glasshouse followed swiftly by Investa's F21 deal in the Sydney Arcade.

However, F21 will open its first Australian store in Brisbane's Queen Street Mall in November this year and Macquarie Centre, North Ryde, in December and aims to be in Pitt Street Mall about mid-next year.

The first Australian H&M store, in Melbourne, was said to have turned over sales of about $10 million per month from the 5000 square metre site, equal to about $24,000 sales per square metre per annum.

In comparison, F21 did about $45 million per annum in Morumbi, Sao Paulo, Brazil from a 1000 square metre store, or about $45,000 sales per square metre per annum.