Contractor HBG is working on two major projects in central London that will both boast strikingly glazed entrances.

The firm has recently started work on a £115m office block designed by architect Make at the former Marks and Spencer headquarters building on Baker Street, London. The company was appointed as a pre-construction advisor for the job by client London and Regional Properties last September. The project team on the scheme also includes QS Tweeds, structural engineer Expedition Engineering and services engineer Blyth & Blyth. The scheme will create 61,735m2 of office as well as three-storey town houses and leisure and retail facilities.

HBG has also started work on the £40m second phase of the Darwin Centre at the Natural History Museum, also in London, which will house the museum's collection of botany and entomology specimens. The new phase is due to open in 2008. The project team on the scheme includes project manager Heery International and QS Turner & Townsend.

• Consultants Buro 4 and AYH are both working on two further projects in central London. Buro 4 is project managing a £2m office block on High Holborn, which is expected to be built by contractor Skanska. AYH is QS on a £70m fit-out of the St Pancras Chambers, which will be reinstated as a hotel.