Innovative underfloor air conditioning used in award-winning renovation of grade-2 listed London landmark

AET Flexible Space was contracted to supply the innovative underfloor air conditioning (UfAC) system to 24 St James Square. The brief for AET was to maximise floor-to-ceiling heights within the constraints of the original building while providing flexible air conditioning at each floor plate.

The office space within 24 St James Square was no longer fit for purpose and required significant refurbishment. The remodelling of the office interiors at all levels was driven by seeking to maximise floor space and take full advantage of views from the double aspect interior.

One of the key challenges presented by the refurbishment of 24 St James Square was the need to simultaneously preserve key architectural features of the building, whilst at the same time providing flexible, modern, premium office space that would suit the requirements of incoming tenants. This is a challenge which simply could not have been met with an overhead air conditioning system.

In almost all cases, AET’s UfAC system met the requirements of this refurbishment, and in any cases where the standard system did not meet the specification, AET was able to design bespoke elements to solve the problems. Crucially, key architectural elements of the building were preserved, including the original ceilings.

Headroom height and conservation were key considerations during the refurbishment, and by using the AET underfloor air conditioning system with a floor void of only 200mm the contractors were able to eliminate much of the ceiling-based services and ductwork, and to enable the ceiling plasterboard to be almost tight up to the slab soffit above.

The installation of an overhead air conditioning systems using ducting would have taken up valuable headroom on each floor, as well as covering up the building’s original ceilings and creating awkward junctions where window heads would otherwise meet suspended ceiling grids.

AET’s UfAC CAM-V system makes use of the space beneath a raised access floor to create the air ventilation path, eliminating the need for ceiling-based services and associated duct and pipework, and at the same time maximising the floor to ceiling heights. The underfloor system creates a brighter and more airy office environment, and also means that the services can be maintained at an easily accessible level. 

A key goal for the refurbishment was to design and build a flexible workspace which could adapt to changing needs in the future. AET’s UfAC systems provide far greater flexibility than ceiling-based air conditioning systems. Once an overhead ceiling air conditioning system is installed it is not possible to easily reposition the fans. AET ‘s UfAC system is inherently flexible, modular in design, and are installed at floor level, making it easy to install, maintain and re-arrange to suit the changing needs of the workspace. AET’s FantilesTM can easily be relocated, offering huge savings when reconfiguring and adapting workspace.

A common complaint from staff prior to the refurbishment was the variation in temperature across the office space, and the cold draughts caused by the ceiling-based air conditioning system. Due to AET’s unique control solution it is possible to set the temperature and air flow to zone requirements. AET’s UfAC solution is designed to create minimal draughts and allow for individual control of temperature and fan speeds, creating comfortable and adaptable working environments throughout the office space.

The 24 St James project has already won the “Best Office Architecture London” award at the 2019 International Property Awards, and the space is currently being let as Grade A office space by BNP Paribas Real Estate.