The £10bn development comprises two schemes led by Peel Holdings; Wirral Waters and Liverpool Waters. Located on either side of the River Mersey at Liverpool’s famous docklands, the two projects are amongst the largest regeneration schemes in the UK.
One of the first flagship schemes to be constructed within the 500-acre Wirral Waters regeneration scheme is the Tower Wharf Project, a 48,000ft² Grade A office building constructed by Eric Wright Construction on behalf of developer, Longmeadow Estates with support from the European Regional Development Fund (ERDF).
The four-storey waterfront office building was designed by Liverpool-based architects, Falconer Chester Hall. While its design concept references Liverpool’s past and the trading vessels that once traversed the waters on its doorstep, the building remains forward focused on sustainability and has been designed to BREEAM ‘Excellent’ standards.
Explains Managing Director of Eric Wright Construction, John Wilson: “Tower Wharf was the first office scheme to start on site at Wirral Waters so it needed to set a benchmark for sustainability within the multi-billion pound development.
“Part of the ethos of the regeneration is to create opportunity while reducing the environmental impact of economic growth. Tower Wharf has been designed to align with those goals and achieving BREEAM ‘Excellent’ was one of the stipulations of the ERDF funding.”
Thermal performance
While Tower Wharf has been constructed on brownfield former dockland, managing the environmental impact of the scheme was paramount from the outset, with ecological reports carried out to assess the flora and fauna at the site.
The largely glass facades provide stunning views across the waterfront and also maximise natural light, reducing the reliance on electrical lighting within the offices and creating a feeling of space for the high occupancy building.
The thermal implications of this aesthetic approach also had to be carefully incorporated into the design. Extensive thermal modelling and daylight calculations were carried out to inform design of both the fabric of the building and the lighting and that attention to detail is instantly recognisable in the scheme’s appearance.
Brise soleil have been incorporated onto a single facade, to reduce solar gain on the south facing side of the building and lesson the cooling load requirements.
Internally, custom-specified blinds have also been installed on the south facing facade. These blinds feature specialist heat reflective fabric that maximises heat during the winter and reduces solar gain in the summer, along with perforations that ensure that the vistas are maintained despite the window coverings.
Building management
At the heart of Tower Wharf’s energy efficiency is its building services installation, with an efficient heating and cooling system, controlled and monitored by a programmable BMS (building management system).
The BMS has been designed to enable the building’s facilities team to monitor inputs, outputs, directories, alarms and plots on a touch screen unit that interfaces with all plant and sensors in the building. The system will enable the occupier to adjust operating times and adjust controller parameters, and monitor alarms, but can be configured for security to ensure that only authorised personnel can alter settings.
John continues: “The system logs and monitors the building services aligned to the occupier’s needs and all data is accessible as graphs.
“What this means for the long-term efficiency of the building is that any faults or under performance is identified earlier so that issues can be rectified before energy efficiency performance is affected.
“It will also enable the occupier to monitor and map energy consumption so that any anomalies or potential savings can be identified.”
Heating and cooling
The building has been designed to provide an entirely controlled environment in terms of heating and cooling with no natural ventilation.
Each of the scheme’s four floors has been divided into four zones, future proofing the offices to enable different areas to be heated and cooled individually. However, the call centre operator that has leased the entire building will utilise three storeys as open plan, high occupancy contact centre spaces, with offices on the top floor. As a result, each floor will be treated as a single ‘comfort’ zone.
John explains: “Because of the open plan layout and the high occupancy levels, creating different comfort zones on a single floor could potentially see heating and cooling conflicting and wasting energy.
“Instead, a highly efficient VRF (variant refrigerant flow) system has been specified using air source heat pumps to provide all the energy requirements for both the heating and cooling.”
Due to the high occupancy levels, the cooling load for the building is significant and heat recovery has been built into the system via VRF fan coil units on each floor. A total of eight Mitsubishi air conditioning roof-mounted condenser units have been installed for the building, each powered by a dedicated air source heat pump.
Two heat recovery air handling units have also been installed on the roof and these had to be designed in a low height, double decker configuration to conform to planning requirements.
Two gas fired boilers have also been installed to provide the energy for the central core radiators and the domestic hot water supply is heated by a further two gas fired water heaters.
Power supply
The high levels of natural light coming into the building during sunlight hours reduce the amount of electric light needed within Tower Wharf and a lighting system made up almost entirely of low wattage LED fittings builds on this energy efficient profile. A wide range of LED fittings have been used across the building, including ceiling panels and spotlights, emergency lighting and feature lighting. All fittings in circulation areas are linked to a presence detectors, and both presence and absence detection has been installed for the office areas in line with BREEAM requirements alongside daylight sensors that control dimming in window areas when levels of natural light are sufficient.
In addition to prioritising low energy consumption, the building has also been designed to reduce the amount of energy required from the grid with a solar PV installation linking high quality roof-mounted panels with two transformerless inverters with a combined 25kW capacity. Once again, the building’s south facing position has influenced this element of the design, with an installation positioned to maximise the available solar energy to provide an estimated output of around 22,500kWh over the course of a year, which, if not utilised by the building demand, is fed directly back into the grid. Lasting legacy
John summarises: “Completion of Tower Wharf is a significant milestone in the ambitious regeneration programme at the Mersey Waters Enterprise Zone. It represents the start of a new era for the dockland location and a commitment to creating a more sustainable built environment to support Liverpool’s future prosperity.”
*Images courtesy of David Millington Photography Ltd
