Mansel Court in Wimbledon

Built in the 1960s, Mansel Court's single-glazed windows with metal frames and poor seals leaked heat and energy. Our skills have since transformed it into a state-of-the-art eco building that’s over 50% more energy efficient than it was, making it a popular place to work for tenants and enabling the landlord to get a better yield.

This was our second project for the Low Carbon Workplace (LCW), following Grove House in Hammersmith.

Sustainable office space

LCW buys old property to modernise and increase its Energy Performance Certificate (EPC) to at least a B rating. This future-proofs the property against rising energy bills and new environmental regulations such as the minimum energy performance standard - set to restrict the letting of buildings rated F or G from 2018. Working with LCW as constructor, our aim was to deliver its vision for efficient and comfortable space for occupants while also making it an attractive investment for the landlord.

More floor space

Working on the 1970s concrete-framed office block, we delivered significant changes to the building envelope to provide the higher energy efficiency.

A key feature of our construction work was increasing the lettable floor area by 60% and we did this by raising the number of storeys from four to five, while also adding a rear extension. Identifying ways to reconfigure buildings to increase their value is part of our skill-sets.

UK first

To achieve the energy performance, we're proud that Mansel Court was the first commercial office building in the UK to use capillary matting for cooling, a major reason for the high energy performance. Another element is LCW’s unique strategy to support tenants before and after they move in. Fit-out guidance is offered to ensure that the tenants’ plans do not compromise the building’s low-energy strategy. For example, there are strict limits on where partitions can be positioned to ensure that ventilation is not compromised and pipes are not penetrated.

Rigorous monitoring

Tough monitoring since completion has shown Mansel Court is performing well. It produces 56kg CO2/m2 per year, which means tenants are well on the way to achieving the LCW standard that requires occupiers to meet best-practice emissions benchmarks or demonstrate year-on-year improvements. Mansel Court is 50% more energy efficient than equivalent buildings (using industry benchmarks), something achieved through clever use of energy efficient technologies, re-modelling the footplate and deploying a support programme to engage occupiers to make sure the technology is used properly.

Mansel Court shows that an investment in energy efficiency – and the use of constructors like Willmott Dixon who understand how to deliver better performance – produces profitability and sustainability.

Guardian Sustainable Business Award judge:

“The redevelopment of old buildings is exactly where more works needs to be done. Old buildings have a negative impact and the redevelopment of Wimbledon’s Mansel Court into a low carbon workplace was considered a project others could learn from and replicate.”