Rooftop bar The Aviary has been cemented as one of the key tenants for one40william after scoring a tavern licence following an 18-month application process.
Set to open in October, The Aviary will be a 1000sqm two-storey tavern with a rooftop alfresco bar.
The new venue is the third venture in Perth by the Publican Group, which is behind the CBD bar The George and the Nedlands watering hole The Byrneleigh.
It is tipped as a major drawcard for one40william, which is above Perth's William Street underground rail station on the corner of the Murray Street mall.
Publican Group co-owner John Ahern said he was "looking for a venue that has that rooftop feel, as Melbourne venues do".
"It is a venue in a very exciting location that combines some of the attributes of our east-coast venues with the great weather in Perth, which provides outdoor areas second to none," Mr Ahern said.
Publican Group also owns six venues in Melbourne.
Colliers International associate director of retail leasing Peter Millard, who brokered The Aviary lease, said the new venue would establish one40william as the gateway to the emerging popular entertainment precinct in the city, bordered by William, King, Hay and Murray streets.
"Within that pocket we've seen a lot of new bars spring up over the past couple of years - the Generous Squire, Tiger Tiger and Wolfe Lane to name a few -- together with some fantastic refurbishments like the former Bobby Dazzlers into The Boheme and the new rooftop bar at Carnegie's, The Conservatory," Mr Millard said.
"The Aviary will sit at the top of that precinct."
The rooftop bar, which will be one of the biggest in the city, will be visible from all the major buildings in the CBD.
Work on its multi-million-dollar fitout is tipped to start next month.
The Aviary will be a mini-anchor tenant for one40william and would also help bring the area at the top end of William Street, which has been affected by roadworks and construction, to life.
Mr Millard said one40william "had changed the face of Murray Street mall and added some sophistication to the area."
Owned and developed by Cbus Property, the new landmark weaves fully-restored, existing heritage buildings into its design.
Its two floors of retail cover 6500sqm, with anchor tenant The Herdsman on the ground floor on the William Street side.
The Aviary will sit on the first floor, along with national streetwear store Globalize, which opened this month, and a food court offering fare including sushi, Chinese food, kebabs, pizza and curry.
One40william has an occupancy rate of 95 per cent, with three of nine spots in the food court still to be filled and two vacancies on the ground floor.
Other shops, all on the ground floor, included Staccato shoe store, Forever New fashion clothing and accessories, iWorkshop computer store, an Optus shop, Swarovski Crystal and a Coffee Club.
The State Government is leasing the entire office space in the building, which totals 35,500sqm, and will start moving in this month.