Mosaic Architecture + Design is seeking detailed planning permission and listed building consent for the building, which has lain vacant since 2017.

The building is held within Orion European Real Estate Fund V.

Along with comprehensive internal alterations creating a light-filled and activated atrium, the proposals include plans for an exciting redevelopment of the fifth and sixth floors within the roof to create impressive office floorplates, flooded with natural light and landscaped roof terraces for outside enjoyment and appreciation of the local skyline.

At ground level, the extension of the public realm will be provided to Bothwell Street providing an enhanced entrance and activation of the street front with a new café and business hub.

The architectural design is a result of a collaboration between Mosaic Architecture + Design and the international design studio 10 Design.

The development will provide modern and energy efficient office accommodation in a complete refurbishment that is both contemporary and respectful of a listed building with such character. The building will be ready for occupation towards the end of 2022.

Richard Low of Orion Capital Managers said: “This project represents a £35 million investment in Glasgow to create high specification, energy efficient, contemporary office accommodation in the very best location in the city at a time of constrained supply of grade A office space.”

Stephen Mallon, director of Mosaic, added: “It is a pleasure to be entrusted with the refurbishment of this important listed building. The project represents a significant investment in both the building and part of the city, which is well deserved.

“The design of the roofscape within the volume of the existing roof should be transformative in terms of the quality of space provided. Allied to the new atrium, this will provide lots of natural light and a vastly improved office floorplate, a true example of sustainable development.

“It has also been good to collaborate with 10 Design and push for a design-led approach across the whole team.”

Gordon Affleck, design partner of 10 Design, stated: “As a refurbishment it is not a typical project for our studio, but after working successfully with Orion on the New Town Quarter development in Edinburgh, we were delighted to be invited to transfer the ethos of wellbeing with the context of an existing building of such character.

“We aim to provide a series of internal and external amenity spaces that include a series of rebated terraces within the original roof volume that allow users to interact with the character of the listed stone façade while flooding the floorplates with natural light.”

Mosaic is working with an experienced design team to deliver the project and the wider team includes 10 Design, Ryden, Woolgar Hunter, Hollis and Atelier 10.