Retrofitting our Chancery Lane office

Our engineers pioneered innovative building systems to upgrade our London office. The result is a space that drastically lowers energy demand, enhances our teams’ wellbeing and promotes productivity.

Location

London, United Kingdom

Client

WSP

Commercial buildings account for 23% of carbon emissions from the built environment in the UK. This means that retrofitting to reduce operational emissions is key to achieving net zero. Across the country, our talented engineers help clients transform existing buildings to cut their energy use and create exemplars of sustainability. So when the lease on our five-floor office at 70 Chancery Lane came up for renewal, we applied this expertise to shaping our own workspace into a pioneering retrofit.

After examining the pros and cons of staying put or moving to a different building, we concluded that staying in Chancery Lane would enable us to radically redesign the building systems: going all-electric and drastically reducing energy demand while taking advantage of free cooling. We also saw an opportunity to work with our landlord to agree the level of investment and future-proof the building to safeguard the long-term value of their asset. In addition, it was clear that the building’s partially glazed façade – like those of other commercial properties in the Fleet Street quarter of London – would lend itself to retrofitting to improve performance.

of the year the systems can use outside air for free cooling

~ 80%

reduction in operational energy demand

65%

Real in-use data to support building performance and future adjustments

Combining our expertise in low-energy projects and our experience in the commercial office sector, our engineers created a future-ready design that took advantage of the UK’s temperate climate. The mixed-mode all-air heating, ventilation and air-conditioning (HVAC) system will reduce our operational energy use by around 65%.

Designing a responsive and efficient system

Free cooling comes from connections to the façade on each floor. When conditions are right, the system can bring air directly in from outside and use it for cooling without the need for chillers. At other times, heat from the building can be recovered and reused at the air handling units, with reversible heat pumps at roof level providing low-carbon heating.

We also introduced louvres on office floors to supplement the building’s air supply. They are connected to a smart building management system (BMS) that manages fresh air flow around the office based on occupancy and CO2 levels. Because it’s linked to the integrated booking system, the BMS knows when each meeting room is booked and can bring the temperature and air circulation up to the optimum levels in time. Should people not arrive for their booking, the system is able to detect that the room is empty and can shut off the heating and circulation to that room to save energy.

To reduce energy use further, we are developing a split HVAC system. We designed two plant rooms: one for the east side of the building and one for the west side. So if occupancy is low we can direct people to use only one half of the building and shut the other side down to save energy. This will be implemented post-occupancy, combined with staff engagement that encourages people to adopt behaviours that reduce energy use.

Closing the energy performance gap

How can we be sure that our aspirations for reducing energy use will become reality? We are using the NABERS process, which rates the building’s energy efficiency through design, upon completion and post-occupancy. The NABERS energy rating will enable us to meter and validate our operations, ensuring we achieve our modelled performance.

Although this was our own office, we approached it just like any other project – with our specialists in building services, acoustics, structures and fire all contributing to a project that will benefit our own people and act as a showcase.

Sam Smith Technical Director, London Building Services, WSP

Sam Smith Technical Director, London Building Services, WSP

This retrofit was as much about our people as about energy and technology; we’ve taken the opportunity to transform our working environment so that it enhances wellbeing and promotes productivity. The smart, responsive system does more than maintain optimum levels of comfort while reducing energy demand – it also enables us to work more effectively. For example, the desk booking system integrated into the BMS is zoned so teams can sit together and collaborate.

Encouraging connection and teamwork

All the spaces feel light and airy thanks to the increased ceiling heights and exposed services enabled by the all-air HVAC solution, which removed the need for fan coils. Responding to the rise in hybrid working since the Covid-19 pandemic, the new design introduces more collaboration spaces and areas for people to catch up with colleagues. A central spine of tea points in front of the lifts encourages people to connect with colleagues, rather than heading straight to their desks, and to use collaborative areas during their breaks.

The first floor includes areas to host internal and client events. This multi-purpose, flexible space has partitions that can be opened up for larger events, ensuring 70 Chancery Lane is both a home for our teams and a welcoming space for our clients and partners.

As we focus on our new office environment, we’ve been careful not to neglect opportunities to minimise waste and create social value from the old space. We reused some of the furniture on other projects, and our removals and storage supplier handled furniture donations to charity partners. Any furniture that we couldn’t reuse was carefully dismantled to maximise recycling.

We’re excited about both our future in our upgraded Chancery Lane office and the opportunities to help our clients realise similar benefits for their buildings.

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