Levitt Bernstein’s energy centre for the University of Liverpool satisfies performance requirements, but is driven by its context
Source: Eddie Jacob
Two weeks ago, Technical and Practice looked at the re-cladding of the Grade II*-listed Arts Tower at the University of Sheffield by HLM Architects (AJ 08.04.10), a project in which English Heritage compromised its conservation agenda and deferred to performance criteria.
This week, we feature a project in which conservation was the dominant driver of building form, although performance requirements were also a major influence. The new energy centre for the University of Liverpool, designed by London architect Levitt Bernstein, which was completed in January as part of the university’s Heating Infrastructure Project, fulfils its exacting technical requirements, but its architectural expression is
primarily a response to its site.
The university originally had two high-temperature hot water systems. One had a gas turbine-powered combined
heat and power plant (CHP) and the other had a conventional boiler. In order to improve efficiency, the systems were linked in 2007. A single energy centre was created, providing hot water to the whole campus, with standby capacity that enables one boiler to be taken out of service if necessary. The new system saves energy and reduces CO2 emissions.
The new energy centre accommodates a four million volt-ampere natural gas powered CHP plant facility, comprising three 12Mw boilers and a 3.4Mw(e) gas engine. The principal functional requirements for its external envelope are that it should provide ventilation and facilitate plant repair and replacement. There is also a planning requirement that noise breakout should not exceed the level of the facility which it replaces.
Levitt Bernstein set out to minimise energy consumption by allowing natural light into the building and regulatingheat loss and solar gain. In order to meet the programme, it was necessary to make the planning submission before the size of the principal plant had been determined.
The university chose the site, formerly a car park, for technical reasons. It was close to an obsolescent combined heat and power centre and the existing buried service connections within the district heating mains system ran under adjacent streets.
However, the site is also surrounded by historic buildings, including the Royal Liverpool Hospital, a Grade II-listed monument designed by Victorian architect Alfred Waterhouse. In initial discussions, the planning authority expressed reservations about a utilitarian building on this site, so the project team decided to appoint an architect. As project architect Damian Howkins explains: ‘A dumb shed clad with banal materials was not an option.
The new energy centre has two storeys and a simple oblong plan, with five bays and a 7 x 7m structural grid. Its main axis runs north to south, forming a fourth wing to the Royal Liverpool Hospital with similar proportions to the others. Although it doesn’t set out to match its neighbours, its scale and the quality and colour of its materials are intended to be complementary.
The most incongruous element is the stainless steel chimney. This is necessary for operational reasons and it has to be 46m-high in order to comply with regulations. Its structure is a mast-supported multi-flue rather than a rigid windshield, which reduces its bulk.
Howkins emphasises that, on this site, ‘the simple option of using standard industrial louvres for intakes and extracts was avoided’. For the ground floor, Levitt Bernstein specified removable steel grate panels for the external envelope. They are 1,250mm wide x 1,250mm high to make it easier to demount and assemble them in the future, and they have 22 x 66mm blades tilted at 45° to achieve the specified minimum air flow. These resemble a plinth, with a similar hue and tone to Waterhouse’s brickwork on the hospital. The planners liked this idea.
Sitting on top of this plinth, at first-floor level, is a screen of bespoke diamond-shaped folded anodised aluminium
panels. These are 1,750 x 1,250mm to enable the 900mm diameter flue extracts to penetrate the facade withouttrimming their supports. Their geometry, orientation and 300mm projection provide the 45m² free area that the plant requires. They lend the facade texture, scale and a unique architectural interest that enhances the building’s setting.
The east facade is fully demountable to allow each of the boilers and the gas engine to be removed for maintenance. There are 2mm-thick steel sheets behind half of the panels, which regulate the free area of the facade. At one stage, Levitt Bernstein proposed perforated sheets behind all of these panels, but adverse weather was a concern due to the site’s marine location. To limit noise breakout, items of plant were supplied with specified acoustic ratings and the noisiest element, the gas engine, has a sealed enclosure with acoustic dampers.
Levitt Bernstein has shown that, on certain projects, there is a loose fit between architectural expression and perational requirements and that, with an understanding of performance criteria, it is possible to concentrate on other priorities, such as urban design.
Name of project Heating Infrastructure Project, University of Liverpool
Start on site July 2008
Completion January 2010
Form of contract JCT 05 Standard Building Contract With Quantities (SBC/Q)
Gross external floor area 630m
Construction cost £13.7 million excluding VAT
Client University of Liverpool Energy Company
Architect Levitt Bernstein
Structural engineer Curtins
Services consultant Nifes Consulting Group
Cost consultant Davis Langdon
Project manager University of Liverpool Facilities Management Department
Landscape architect Levitt Bernstein
Main contractor EMCOR Engineering Services
CO2 emission savings 6,700 tonnes per year
Blocks Hanson Thermalite Turbo blocks
Secondary steel roofmembers Metsec Roofing Corus
Fall arrest system Latchways
Door closers Allgood
Plasterboard British Gypsum
Insulation Kingspan Thermawall
Exterior lighting Weef Lighting
Gutters and RWPs Alumasc
Internal drainage system ACO Technologies
Paving Hardscape Products
DPM and DPC Visqueen Building Products
Internal balustrades Kee Klamp
Floor finishes Tremco Illbruck
Heating infrastructure: Levitt Bernstein's energy centre at Univsersity of Liverpool