The job is ISG’s latest win from luxury residential developer Amazon Property.

It will see ISG remodel and refurbish 92-96 Portland Place, 98 Portland Place and 10-12 Park Crescent in a single rolling programme.

The three Grade II listed buildings overlook Regent’s Park and were originally constructed as upmarket London residences in the early 19th century and designed by John Nash.

They are now predominantly used as commercial office space.

ISG will extensively reconfigure and refurbish the three buildings to create 15 new luxury apartments. Two of the buildings already contain existing residential accommodation, which will remain occupied throughout the duration of the project.

The Enquirer understands that Swiftline will be providing building services on the job under a design and build contract worth £4.5m.

ISG will commence the first phase of the project by re-building the rear of 98 Portland Street reconfiguring the interior layout to create additional space.

The existing roof on the property will be raised and a new mezzanine level constructed, further increasing the overall floor plate.

Across the two adjacent properties, ISG will again add mezzanine structures and reposition the floor levels in a complex programme of work that incorporates extensive structural modifications.

Externally, ISG will clean the facades of all three buildings, carrying out any necessary repairs to the stonework and replacing all windows with sympathetic and high performance units.

Alan McCarthy-Wyper, managing director of ISG’s construction business,said: “Amazon Property has built an enviable reputation for acquiring prestige properties in landmark London locations and refurbishing them to the very highest standards that appeal to a global residential market.

“I am delighted to be able to support Amazon Property return these buildings back to the use originally intended by John Nash in the early 1800s.

“These projects will showcase our skills and expertise across a scheme with great technical and logistical complexity.”