Kentish Town Sports Centre

Max Fordham Engineers has turn Victorian technology to good use in the refurbishment of one of London’s oldest pools. Max Fordham Consulting Engineer’s brief was to make the grade II listed Kentish Town Sports Centre, due to open to the public on July 26, more energy efficient, reducing its running costs. It achieved this by using one of the original late Victorian 140m-deep boreholes that existed on the site, which is bounded by Grafton Road, Willes Road and Prince of Wales Road. The borehole had previously provided water, pumped from underground, for the showers, WCs and three swimming pools. Fordham’s has made the borehole work harder, using water from the borehole to heat the pools and cool the fitness studios all year round. When St Pancras Public Baths, as it was originally called, was first built in 1900-1901, to designs by Thomas Aldwinckle, two boreholes were created to provide water to four swimming baths, 129 slipper baths and a wash house. The boreholes were still in use in 1960 when a major refurbishment was carried out. An unsympathetic alteration to the four original swimming pools left only three pools remaining: the 30.5m-long Willes Pool, the 25m-long Grafton Pool and new 9m x 7m level deck learner pool. Since the 1960s, changing social needs as well as the precarious state of the building itself, meant that the centre urgently required modernisation. Parts of the building had to be demolished to achieve the functional and spatial demands of the sports facilities, as well as providing space for housing (four new townhouses, three keyworker flats and seven private apartments) which raised finance towards the cost of the restoration. Now with £25.3 million invested, the design team has transformed the baths into a sports centre with a legible layout that meets 21st century services requirements.

Rooflight refurbishment

One of the high points of the Kentish Town Sports Centre’s refurbishment is the restora-tion of the former first-class men’s pool, now called the Willes Pool. With the original roof lantern revealed and the original balustrade to the spectator gallery reinstated, it will be an exhilarating experience to swim here. Max Fordham’s services strategy has been critical in making the centre operate more efficiently, but it has also been important to upgrade the existing rooflights and roof to improve the centre’s thermal and solar performance. The glazed roofs to the Willes and Learner Pools and the fitness gym roof have had their loose-fitting, single-glazed rooflights replaced with fixed double glazing. Existing slate roof coverings have been removed and replaced to enable the insertion of insulation and vapour barriers. The walls to the existing buildings are of a substantial thickness and already have a reasonable U-value (1.0W/m2K). These measures, in addition to Fordham’s specification of a highly efficient mechanical ventilation plant, will minimise fabric heat losses and reduce energy consumption. The Kentish Town Sports Centre scored a Breeam “very good” rating. A key contributor to the score was the reduction of CO2 emissions, a 36% improve-ment over Part L building regulations.

Borehole strategy

The strong appeal of taking water from boreholes is that their depth guarantees a fairly constant temperature of 13°C throughout the year. This also makes it suitable for low-energy cooling and energy-efficient indirect heating. With this in mind, Fordham’s devised a strategy to use the borehole water to its full potential. Project engineer and partner at Fordham’s Scott Crease explains that the strategy now covers three different functions: supplying water; heating the three swimming-pools; and cooling the fitness studios and new changing-rooms. There are two existing Victorian boreholes on the site, boreholes A and B, each 300mm in diameter and 140m deep. A services upgrade in 1984, which resulted in a drop in demand for water, meant that when the Centre was surveyed prior to the refurbishment only borehole A was in use. Despite it being in a fairly good state of repair, borehole B was in a better location, in the centre of the development. A test showed that it could deliver about 6.3 litres per second, which satisfied Crease, so it was decided to cap off borehole A, while borehole B was repaired and relined. If borehole A needs to be used in the future, it can be easily connected. As part of Fordham’s services strategy, air-handling units will be equipped with cooling coils that extract heat from the air and transfer it to the borehole water via a heat exchanger. The energy required to pump the borehole water from the ground is less than that required to run conventional chillers, saving a significant amount of electricity. It has been estimated that up to 60% of the cooling energy could be provided without using the chillers. When the chillers are needed, the rejected heat will be used to heat the three pools. It is anticipated that the energy savings from using the ground water for cooling and heating will be more than 10% of the centre’s overall energy use.