London’s largest office owner is pushing ahead with the rare speculative development of a 380K SF London office building, betting that companies will lease green space in spite of the wider malaise in the market.

Landsec on Wednesday said it was starting development at Timber Square in Southwark, south of the River Thames, awarding a construction contract to Mace for the £200M building.

Landsec is committing to the development of the building without a tenant in place, citing sustainability as one of the most important factors driving leasing decisions. It added that Timber Square will be finished by the end of 2025, at which point there will be short supply of new buildings due to developers pausing construction in response to office demand uncertainty.

Timber Square is a net-zero office development, Landsec said. Plans call for combining the reuse of elements of an existing printworks building with a range of modern methods of construction, including the use of cross-laminated timber, to achieve a 50% reduction in carbon dioxide during construction compared to a typical office build.

The project is retaining 85% of one of the existing structures and reusing building materials wherever possible. Once complete, it will become one of the largest commercial developments in the UK to use a hybrid steel and CLT structure.

Landsec has a long history in Southwark, which began with the redevelopment of The Blue Fin Building and Bankside 2 and 3 over a decade ago. It is now investing further into the borough to create a 1M SF green office cluster.

Earlier this year, Landsec and Mace completed work at The Forge, the first office in Landsec’s Southwark pipeline to be delivered and the UK’s first net-zero commercial building designed in line with the UK Green Building Council’s framework.

Data from BNP Paribas Real Estate showed that central London leasing volumes in the first half of the year were 28% down on the same period last year and 16% below the five-year average, while rents for the best buildings are rising.