A complex frame design and tricky services engineering is testing Morgan Sindall on Anglia Ruskin University’s new science centre in Cambridge.
Client: Anglia Ruskin University
Contract value: £25m
Region: East of England
Main contractor: Morgan Sindall
M&E subcontractor: Integral
M&E subcontractor: Roger Parker Associates
Project manager: Gardiner & Theobald
Concrete frame subcontractor: MJS
Demolition subcontractor: Clarke Demolition
Start date: January 2016
Completion date: September 2017
Cambridge is a hive of construction activity. Science and technology industries, coupled with the higher education sector, have made the city an economic powerhouse. In this competitive environment, high-profile architects have been drawn to Cambridge to give new buildings the all-important ‘wow’ factor.
An example of this is the new science centre taking shape at Anglia Ruskin University’s Cambridge campus. Morgan Sindall is main contractor for the £25m project, designed by Richard Murphy Architects.
The 7,773 sq m centre brings together the departments of life sciences, biomedical and forensic sciences, computing and technology, and psychology in one location. Its high-tech facilities include a sound-proofed Faraday cage, cold rooms, and a forensics laboratory to simulate crime scenes.
The eight-storey centre has 291 rooms, including a 304-seat lecture theatre, a 202-capacity ‘superlab’ providing flexible teaching space, and a full building-height atrium in the middle.
“We have built several university projects in Cambridge, and they all tend to feature signature architects – high-concept designs, unique features, challenging to build,” says Morgan Sindall area director for Cambridge Bob Ensch. “This is no exception. It’s not a conventionally-shaped building and scope for repeatability of materials was limited.”
The contract was awarded through a two-stage, design-and-build tender process. Morgan Sindall priced the job at the end of 2014, and there followed a lengthy design development phase during 2015. This ran concurrently with an enabling works package, which included demolition of existing buildings, diversion of high-voltage and live gas supplies that ran across the middle of the site, and then a 6,700 cu m muckshift.
“We rationalised the design – it’s not really value engineering, because we haven’t taken any functionality out of the building – to bring it within budget”
Bob Ensch, Morgan Sindall
Construction of the building began with the piled foundations after the design development was completed and contract close reached in January 2016.
“The original design would have meant a construction cost of around £28m, and the client’s budget was £25m,” Mr Ensch says. “So we rationalised the design – it’s not really value-engineering, because we haven’t taken any functionality out of the building – to bring it within budget.”
The centre’s design partly reflects planning restrictions. The L-shaped building fronts on to the residential Broad Street, and this elevation has been deliberately scaled to align with the houses opposite and conceal the bulk of the building behind.
The Broad Street side houses the administration offices, which have a lower floor height of 2.85 m and domestic-sized fenestration, and includes a basement level. Behind this frontage, the building rises up to its full height, with the research and teaching areas having floor heights of 3.3 m.
Morgan Sindall Anglia Ruskin Excavations with propping for basement
The centre is clad mostly in brick and glazing, with traditional sheet metal roofing. “The design is very clever, because it actually looks quite modest from Broad Street,” Mr Ensch says.
The most striking design feature is the central atrium, which is rectangular on plan but with two cylindrical towers jutting in on one side – which will be timber-faced – and triangular balconies on the other. “The client’s philosophy and vision is that ‘everything should be seen to be available’ once you step into the building,” Mr Ensch says.
The atrium’s unusual shape, and the stepped levels to reflect the different space uses across each floor, made the frame complex both to design and construct.
“It wasn’t easy to find a frame contractor to price the job,” admits Morgan Sindall senior project manager on the science centre Tony Black. “We picked a local Fenland contractor, MJS, and they did a good job with what was a complex formwork design, and also were able to precast around 20 per cent of the concrete above the foundations. Nearly 5,000 cu m of concrete has been used in total.”
Precast elements include columns (excluding the curved ones used for the atrium’s two towers), twin walls for stair cores, staircases and lift shafts. The largest span in the frame is 8.8 m.
Working at considerable height
Much of the M&E installation has meant working at a considerable height. A bird cage scaffold provided access in the eight-storey atrium, with similar structures erected in the super lab and the three storey-high lecture theatre, which extends down to the basement level.
Further complications in the lecture theatre include a steep rake to the seating area and several different angles in the ceiling which accommodates the M&E and AV equipment (the latter is being installed by the university’s own contractors).
“We’ve had to put in a heavy-duty ‘dance floor’ platform on top of the bird cage, because MEWPs are needed for the AV and M&E installations,” Mr Black says.
“About 50 per cent of the ground floor had to have some form of access table put in to enable working at height,” he adds. “Also, we need to install underfloor heating in the atrium, so that will go in at the end once we’ve moved out all the access kit.”
A substantial amount of the concrete will remain exposed in the completed building, including soffits, suspended ceilings and the cylinder columns. The concrete’s thermal massing also provides passive cooling – an important consideration in the M&E design.
Given the extent of the centre’s laboratory facilities, it’s not surprising that M&E accounts for a third of the overall construction budget, even though about half of the savings Morgan Sindall identified during the design development phase was in this area.
“When we tendered the job, the client indicated there was room for flexibility in the services design,” Mr Ensch says. “As the architect was Edinburgh-based, and we felt the M&E needed more specialist co-ordination, we brought in a local architect Saunders Boston and developed the M&E design with our subcontractor Integral and their services engineer Roger Parker Associates. This was key to making the M&E design installation work and achieving the cost savings we did.”
Central to this was identifying duplication in the original services design, says Morgan Sindall M&E manager James Gale.
“All south-facing classrooms were mechanically ventilated, for example,” he says. “So we changed to a hybrid solution, using mechanical fans and natural ventilation from the atrium – through a ribbon of glass louvres – which acts as a big mixing chamber and limits cold draughts in the winter.
“The natural ventilation system also doubles as our smoke control strategy – an innovative saving.”
Another key change was reducing the number of air-handling units from eight in the original design down to three.
Morgan Sindall Anglia Ruskin Atrium internal HQ
“This was achieved by replacing the original chilled water system with a Daikin VRV – essentially a variable refrigeration system that provides close control of temperatures using fan coils within the ceiling voids, so each coil can be either heating or cooling to a different temperature in each room or floor,” Mr Gale explains.
The centre’s energy model has effectively been reinvented, but without compromising its environmental performance. “We were able to achieve the same CO2 reduction as the original design, even though these systems normally mean high CO2 levels. Airtightness is 4 cu m per hour, vastly better than building control [required],” Mr Gale says.
The building’s BREEAM target is a modest Very Good. “We’re installing 200 sq m of photovoltaic panels on the roof, but to get a higher score would have meant introducing kit that simply wasn’t feasible in this building’s budget, such as a ground-source heat pump or rainwater harvesting,” Mr Black says.
The M&E plant is chiefly housed on the roof, apart from two mini plant rooms on top of each cylinder in the atrium.
The centre will be joined onto a neighbouring building, also part of the science faculty, but this interface has posed an unexpected problem.
Morgan Sindall Anglia Ruskin Atrium 3
“The new science centre structure abuts the David Building, which we are cutting into in two places, and the two buildings will eventually be joined by fire doors,” Mr Black explains. “However, we discovered a steel beam which was not in the as-built drawings, so we’re having to cut through it.
“The David Building’s structure dates from the 1950s, and is concrete-wrapped steelwork, so breaking off this concrete and then cutting through the steel is noisy. It means we can only carry out this work at allotted times.”
The logistics management has not been straightforward for the Morgan Sindall team, with a tight footprint, only one access road (Broad Street), and other university faculties plus a primary school neighbouring the site.
Giken silent piling rigs were used to drive the 240 piles in the foundations to a depth of 18 m, keeping noise to a minimum. The two tower cranes on the job – the awkward location meant no mobile cranes could be used – will have to be dismantled by partially using a neighbour’s property, such are the space constraints.
“We’ve delivered a couple of other university projects in the city, so we’re used to working on live campus sites,” Mr Black says.
“It’s not a conventionally-shaped building and scope for repeatability of materials was limited”
Bob Ensch, Morgan Sindall
The project is now at fit-out stage. Some 37 different types of wall make-up are needed to create the required conditions of all the different laboratories, with 1,600 sq m of internal blockwork and almost 22,000 sq m of plasterboard used. All rooms will have acoustic treatments, and in the atrium, the cylinder will be wrapped in acoustic baffle behind its timber facing and a suspended acoustic raft fitted to the ceiling. “The sound reverberation would be deafening otherwise,” Mr Black says.
But even with all these challenges, the Anglia Ruskin University Science Centre is still scheduled for its September completion.