The building has undergone a once in a generation refurbishement. Historic interiors have been reorganised, the basement has been opened up for public use and a new pavillion has been introduced to the roof terrace. The area of the building rebuilt in the 1980s has been completely reconfigured.

The existing building pre-dates the industrial revolution and was originally designed without electricity. The building has good genes with large sash windows and tall ceilings to maximise natural light and natural ventilation.

These important features of the historic building are retained along with an approach to sensitivity upgrade the thermal performance of the original building fabric.

We started with a process of getting to know the existing building. Opening up floors, removing wall linings and establishing vacant void spaces for new services installations.

An ongoing process of in-situ measurements were essential in establishing new routes through the building.

All the existing building services have been decommissioned, stripped out and have been replaced.

The buildings services have been rationalised and reorganised. New more efficient distribution routes utilise existing pockets, redundant voids and chimneys for new risers. This has allowed removal of surface mounted pipework and wiring.

The most historic rooms are simply serviced to avoid distrupting the original character. The Court Rooms, library and committe room will continue to be naturally ventilated with sash windows and doors opening into courtyard spaces. Heating is provided by new radiators operating at lower water temperatures.

Sensitive artworks encased in conditioned frames to enable their prolonged conservation, without needing to control the rooms to close temperature and humidity bounds which would be an energy intensive process.

The Georgian Dowgate Range offices are naturally ventilated. Ventilation boost fans developed to fit inside existing chimneys allow the windows facing the noisy and polluted Dowgate Hill to be closed when necessary.
The top floor apartments are provided with heat recovery ventilation systems which allow controlled fresh air with all windows closed.

The existing basement was previous used as storage. The large vaulted areas have now been opened up for public access. The basement floor has been lowered to incoporate underfloor heating

Many parts of the existing basement had insufficient fresh air. The refurbished basement is provided with all new efficient mechanical ventilation systems with supplementary cooling for the vaults event spaces.

The main banqueting hall regularly hosts events for 170 people. The original natural ventilation openings in the walls and the roof had been lost over time and the room in 2017 had almost no fresh air ventilation.

It is now provided with a dedicated mechanical ventilation system located and concealed in the ceiling space. This system includes efficient heat recovery and the ability to warm or cool fresh air delivered to the room for increased comfort and flexibility. This strategy protects against rising CO₂ levels and overheating during large and lengthy events. The radiators are retained and refurbished to provide heating at low-level. These interventions avoided any alterations to the internal walls and ceilings and now provides the comfort expected of a modern events space.

A key part of the project is to prepare the building for a zero carbon future and an important intervention was the switch from gas heating and cooking to all electric operation utilising heat pumps and induction appliances. This single intervention alone reduces the buildings operational carbon emissions by 50%.

With heat generated at roof level, its storage and secondary distribution is contained within a suite of small vaulted plantrooms in the basement.

Ultimately the overall refurbishment and replacement of the building services systems will bring an improved efficiency to the building operation through the use of:-

• New variable speed direct drive fans in air plant
• Heat recovery within mechanical ventilation systems
• Variable speed pumping in water systems
• Lighting all LED throughout
• Better more efficient and user friendly controls

The operation of all building services systems shall be controlled and monitored via a new central building management system, permitting energy metering at a sub-system level, which is key to ensuring operational energy use is minimised.