The $3 billion, two-tower Central Place Sydney plan, hailed as Sydney's most important CBD development in more than a decade, has new, finalised design specifications that have been fine-tuned.

The 9632 sqm mixed-use project at 14-30 Lee Street in inner-city Haymarket is thought to be a crucial part of Sydney's developing Tech Central sector.

According to the project's vision statement in the development application, the goal is to create “a vibrant new business district and revitalise the face of Sydney’s busiest transport interchange”.

The development, created by local architects Fender Katsalidis and US firm Skidmore, Owings & Merrill, would be located adjacent to software giant Atlassian's authorised $1.4 billion tower at the southern end of the CBD, next to Central Station.

Dexus, the largest office landlord in the nation, and Frasers, the local division of Singapore's Frasers, which own the two existing office buildings slated for refurbishment, have jointly proposed Central Place Sydney.

“The design establishes a new civic space that extends into the workplace—blurring the lines between public and private, while producing a highly vibrant and diversified experience,” the DA said.

“It will be one of the most sustainable commercial developments in Australia, with workplace environments that integrate nature where possible, rely on passive shading and natural ventilation, replace structural concrete with timber, and offer a range of amenities.”

The intended heights of the project's north and south office towers, which are presently on public display, remain unaltered at 35 and 37 stories, respectively. The development would have 9668 sqm of retail space and 145,325 sqm of office space overall.

The two skyscrapers are "expressed as three individual forms in order to reduce their visual density," the DA claims.

The concept has undergone a number of revisions in recent months as a result of issues brought up by the City of Sydney and its design advisory panel.

They mainly concern the open space and the proposal's two smaller buildings, the Connector and Pavilion.

A cornerstone created by Edition Office, The Connector is an office-retail structure encased in bronze mesh that aims to link the development to the street and establish a laneway network connecting Henry Deane Plaza and Lee Street.

Its previously intended connection bridges that would have connected it to the podium and central atrium have been abandoned, and it has been downsized from ten to eight stories.

The Pavilion is a wind mitigation canopy that has been built to double as an activated multi-functional space fronting Henry Deane Plaza. It is located between the northern end of the site and the nearby Atlassian tower. Its layout has been made simpler by getting rid of the intended vertical planting system.

A "reimagining" of the public realm that incorporates an open laneway landscape design that allows for enhanced retail activation is another significant modification. The tower facades have also undergone some minor adjustments, including the removal of the building-integrated photovoltaics system.

In order to create "a harmonious relationship between the two elements," the podium has been lowered by two levels to match the height of the Connector, and the roof terraces at the northern and western ends of the towers will now be converted into landscaped planters inaccessible from the adjacent office space.

Up to August 25, the public can view the updated Dexus-Frasers Property Group proposal for Central Place Sydney.

An subterranean facility for basic utilities, which will enable future over-station development and aid the renovation of Central Station, a significant entryway to the CBD, is another important component of the application.

In the so-called "Silicon Valley" of Sydney, which spans 24 acres across the station's tracks, the NSW government's contentious unsolicited proposal procedure is expected to result in the major development known as Central Place Sydney.

Buildings up to 206 metres tall can now be built in the region around the station's western side, as opposed to 35 metres previously.

The project is expected to create 700 jobs during construction and will accommodate more than 10,000 workers on completion.