In designing a riverside replacement for Chelmsford’s main swimming pool and gym, Pick Everard followed a brief to increase local community participation. James Parker reports
In 2014, Chelmsford City Council undertook a condition survey on the only sports complex with a pool in the city boundaries, an outdated 1960s building with 1980s additions. This found that the centre could be kept running with a £9m refurbishment, but it would not be able to meet increasing demand; what’s more the council had a strong goal to increase participation in sports and leisure in the local community.
The decision was made to retain and refurbish the viable elements of the centre – the 1980s ice rink and sports centre – but provide a new, fit-for-purpose, modern pool and gym to replace the old facilities, driven by the motto of “the best leisure offer for the most people.” The £30m works were supported by a £1.5m grant from Sport England, who have “changed focus from an elite sports body to being more about increasing health and participation,” says project architect at Pick Everard, Justin Ashworth.
Against this background, it was key to make the building as inviting as possible to the community, and enhance its function as an important public building for Chelmsford. In light of this, the client wanted to appoint an experienced practice, and Pick Everard have delivered a wide array of sports and leisure projects, such as an Olympic legacy project at Hadleigh Park, as well as military training, school pools, and local authority swimming pool refurbishments across the south east.
The replacement pool and gym scheme was originally developed up to RIBA stage 2 by specialist architect Paul Weston, who “helped the council make decisions on strategy, such as around keeping the old pool open while we built the new one,” says Ashworth. He adds that the constraints around the phased construction “kind of selected the site for us, because we built on the car park while the old centre was still in operation.”
As well as Weston’s expertise, the project benefitted from Sport England’s input – from helping make the business case robust and futureproofed, to assisting the council with programming at the centre, and “links with clubs and organisations at national level” to help ensure the centre’s potential is used to its full.
The organisation also has the knowledge (including via its links with Swimming England) to provide design advice on the pool itself, and Pick Everard worked closely with Sport England technical adviser David Hemsley throughout to ensure that the pool had a robust specification. “It means we are providing the client with a building that has proven finishes and construction methods – ones that Sport England know lasts,” says Ashworth. He mentions that as well as attending early design meetings and providing feedback, Sport England also regularly attended site progress meetings to ensure the specification was being delivered. He adds: “This building will be used 364 days a year, from 5.30 am until 10 at night, and a million people a year will go through it; it’s getting close to airports and hospitals in terms of the robustness we need to achieve.”
Brief & form
The council wanted a “public-facing, inclusive design” that would also contribute to the wider riverside development in the town, including the major Bond Street retail and leisure development. “It’s all part of a riverside quarter that the council has had a long-term ambition to redevelop,” Ashworth explains, praising the planning department’s work.
The new build accommodation includes a 10-lane ‘competition’ pool (wider than the standard eight lanes due to the demand resulting from being the only pool in the city), plus a splash play pool, flume, and learner pool. There’s also a crèche and soft play, and cafe. On the first floor is a 150-station gym, and a studio dedicated to spin classes, plus two multi-purpose studios.
The scheme’s design responds to its forbears on the site, says Justin Ashworth. “We looked at the retained ice rink – it’s built on columns with parking at ground floor level. So we made the ground floor of the new build elements as transparent as possible, with solid forms at first floor.” This helps explain the strip of glazing running around the building’s perimeter at ground floor level, which includes a blue film around the pool helping control glare, and giving a “clean feel.” The interlayer used in the glazing – which also helps connect the building with its surroundings – adds user comfort, warming up in sunlight to prevent cold internal downdrafts.
As part of increasing participation in the centre, the council “wanted the cafe to be public-facing,” says Ashworth, whereas in the previous building the cafe was for centre users only. “This is much more a cafe by the river, with a leisure centre behind it, if you don’t want to come and use the leisure centre, you can still get a coffee on your way to work.”
The riverside frontage to the gym, curved to follow the bend of the river, extends over the cafe to provide a protected external terrace. Further cantilevered forms at first floor house the skate hire for the existing ice rink, and the spin studio; these also signal the two entrances to the building which are directly below them. Further protecting users walking around the facility, a colonnade runs around the building with columns to both the front and side elevations, echoing the pre-existing sports centre.
As Ashworth says, the colonnade “gives the building added presence – this is important for a civic building and also softens the transition between the building, terrace and riverside walk.” The architect says that he believes leisure centres deserve to be considered alongside theatres, galleries and churches when it comes to their standing as public buildings. “I put them in the bracket of proper civic architecture that we want to be proud of. It’s a building that’s not to be taken too seriously, but it is an important public building.” This new addition also creates a new ‘gateway’ to the city, part of its success being in enhancing the existing riverside walk connecting it to the city centre.
Justin Ashworth says leisure centres also enable designers to “have a bit of fun” and the exterior of the building has a playful expression of coloured glass to the gym, and ‘bubbles’ extending up the pool’s facade – celebrating what’s happening within. The bubbles have been laser cut in various sizes into white aluminium sheet bonded to a blue sheet behind; the architects hope the projecting roof of the colonnade will protect the bright white exterior from staining.
Also from Alucobond (and supplied by cladding specialists Ash & Lacy), coloured panels cover the cantilevered sections internally and externally, their powder coatings changing from appearing blue to greens or reds depending on the light and the angle they are viewed from. “It almost changes colour with the seasons,” says Ashworth.
A further playfulness is bestowed by the vertical louvres that frame the full-height glazing to the gym on the first floor, in a sequence of blues and greens. As well as having pleasant views of trees framed by these colourful brise soleil elements, gym-goers benefit from the solar control they provide. The east-facing elevation is fully shaded in the hottest parts of the day, enhancing what the low-G solar control glass itself is doing.
As well as the ‘blue’ glass around the pool, blue external LEDs enhance the exterior at night, making the building glow. In addition, the gym has colour changing LEDs on the interior – which “almost ripples like an octopus,” says Ashworth – adding that the building “completely changes at night.” To the west elevation are three projecting oriel windows with brightly coloured frames, continuing the language of colourful protrusions.
Structural challenges & pool
Digging a pool tank next to a river on a site with difficult ground conditions “presented unknowns at the beginning of the project,” says Ashworth. “We worked with main contractor Kier and the piling contractor to develop the design for a contiguously piled structure around all of the pool and basement areas.” This worked well, with minimal dewatering of the site being required during the works.
However there was also the issue of an adjacent sewer to contend with – the main sewer serving the whole of north Chelmsford. The building needed to be moved slightly further back from the river, and there were early delays because of other groundwork risks that needed to be addressed.
The pool is constructed of reinforced concrete, render and tiles, and half of its floor is movable for flexibility of use, allowing a variety of classes from learn to swim to ‘aquafit’ to use it as required. “Lane swimming can be maintained in the deep part, and for competitions the whole pool can be set to 2 metres deep in a matter of minutes,” says the architect. A plastic ‘boom’ runs down the centre of the pool – a box which descends into a trench or ascends to water level in order to provide two different depths as required. Other innovations include an underwater camera-based system that warns lifeguards of users who are possibly in trouble.
There’s also a shallow learner pool in addition to the fun ‘splash’ pool, with the former having sensory features like bubbles and water jets, lights and music, which is not only fun for children but beneficial for profoundly disabled users or even ‘chill out’ sessions for adults.
For the pool roof design, the architects and structural engineers had the task of “creating an elegant structure spanning over 30 metres, and providing column-free views from the spectator area.” The solution was ‘fish belly’ glulam trusses with galvanised steel chords. The roof’s diagonal, self-bracing form allowed cross-bracing in the walls to be reduced and provide a band of clear glass at ground floor “without structural interruption.”
It is obviously important to ameliorate acoustic control where possible in pools, and extensive acoustic panelling is found here to make swimming teachers’ lives easier. The comfortable acoustic produced “adds to why the building ‘feels good,’” says Ashworth, “although a customer may not appreciate exactly why.”
With, as Ashworth asserts, it being impossible to guarantee energy efficiency from a passive building for such a use class when it comes to sustainability aspects like ventilation, the focus of the design was instead on minimising solar gain. As well as the glass and brise soleil mentioned previously, the design maximises overhangs to shade the ground floor, and provides deep eaves. The blue film to the pool’s glazing absorbs as well as reflects heat, and there are smart sensors to maximise lighting and heating efficiency.
In addition, a retained CHP unit from the existing centre was recommissioned and relocated in the new plant room. This “works efficiently for the heat load of the pool and the centre’s hot water requirement,” says Ashworth, topped up by ‘smart’ gas boilers if needed. Underfloor heating runs throughout the ground floor. The centre’s targeted ‘Very Good’ BREEAM rating will “put it in the top 25 per cent of non-domestic UK buildings for environmentally-friendly design,” says the project architect.
When it comes to the copious ductwork required for the servicing of a swimming pool and gym, the architects “as far as we could,” kept the ductwork on the roof and out of the internal spaces.
Beyond the pool’s movable floor and the building’s colourful, engaging design, what really marks this project out among sports and leisure schemes, according to the architects, is the “client’s commitment to maintaining the long-term quality of the building.” Lifecycle, maintenance and safety issues were a “key factor in making decisions,” in what was a very robust specification based on specialist sector knowledge, and this should guard the project against the failures that have tainted other such schemes initially lauded for their design.
With the project being a traditional JCT contract, Pick Everard remained in control for much of the detailing, which was a further contributor to a high quality outcome, it being a highly experienced firm. Where site issues did arise, the architects attended in order to directly resolve any queries and questions.
The result is a building which was always going to prove popular due to its key role as the only pool in town, but has exceeded expectations. Admissions have increased month on month since it opened in summer 2019, and the centre’s on track for a million visits in its first year of operation. The wide participation hoped for by the client is evident, with elderly pensioners sharing the space with school groups, plus a “very active programme” for disabled users, says Justin Ashworth, adding that this ties into to the intense focus on such users during the design programme, which included an access group dedicated to DDA and similar considerations.
Beyond the strengths of the new spaces and playful exteriors created, the final piece of the jigsaw is the lengths that the staff go to to assist users, no doubt inspired by their bright and colourful new home – in fact this is evidenced by the number of side projects that have been catalysed by the centre’s completion. Says Ashworth, “they go the extra mile to ensure users are welcomed and have a positive experience.”