This highly visable energy-from-waste plant in Jersey has its structure on the outside
Architect Hopkins Architects
Location St Helier, Jersey
Jersey’s La Collette energy-from-waste plant, which came into use last year, was built on reclaimed land next to an existing power station close to the island’s capital St Helier. Its coastal location and close proximity to the town meant it would be highly visible and, in an unusual move, the client appointed an architect — in this case Hopkins Architects — to design the £120 million facility.
The building consists of an internal concrete and steel superstructure, which provides the support needed for the process plant and its equipment.
“We came up with a really simple concept,” says Hopkins senior partner Jim Greaves. “We took the energy-from-waste process and shrink-wrapped the envelope around it and put the structure of the building outside. This creates a naturally interesting top to it and by placing the main columns and wind bracing on the outside we have a natural articulation that has an interesting lighting effect.”
The cladding on the long east and west elevations is a profiled steel composite panel that spans 4.2m between the bespoke fabricated wind rails. On the east elevation, perforated profiled steel panels with windows inside were employed on five 8m-wide bays to allow daylight into staff areas while retaining a consistency of appearance. Completing this group, a fully glazed bay using double-glazed structural glass marks the plant’s control room.
The gable ends are also glazed, to draw in daylight and to reveal the inner workings of the industrial process. This helps reduce the perceived bulk of the building.
The eaves height, at 32m above ground level, was determined by the need to accommodate the electricity generator and flue-cleaning process, and also to house the large crane used to load the hopper and remove bulky waste. Steel trusses rise a further 5m above the roof and are exposed to provide articulation without adding bulk, a strategy used by Hopkins for its fly tower at Glyndebourne Opera House.
Inspiration for the design came from Behrens’ AEG Turbine Hall, Mies’s Crown Hall and Team 4’s Reliance Controls Factory. But its influences also came from closer to home. The Jersey Electricity Company power station next door is easily pinpointed by its landmark 90m-tall concrete chimney.
“The chimney is what it is, an unashamed piece of industrial kit that was built with some care,” says Tony White, associate partner at Hopkins. “The La Collette plant takes the same approach.”
Being located beside the power station enabled the new plant to make use of its chimney, cooling water system, gas oil system and demineralised water system.
By working with the process engineers the plant was rationalised. One major layout change was the removal of the bulky waste element to a separate facility nearby. This meant the footprint could be reduced to 80m x 36m and unnecessary height avoided.
It has been estimated that in its first 25 years the new plant will generate 1,600GWh of electricity, helping to reduce Jersey’s dependence on imported energy.
A structural hierarchy in steel
The envelope of the La Collette energy-from-waste plant can be thought of as an assembly of primary, secondary and tertiary structures, all visually expressed and made from steel, a material that offers the robust nature required for a large industrial facility.
The primary system is constructed from circular hollow section columns at 16m centres along the length of the building, with 5m-deep open trusses spanning its width to support the roof.
The secondary structure is constructed from bespoke fabricated wind rails, spanning 16m horizontally from column to column. The rails have a circular hollow section outer flange, a flat back flange that carries the cladding panels, and a horizontal web that is perforated with lozenge-shaped holes that allow water to drain and reduce visual mass and dead load.
The tertiary structure is made from the profiled cladding panels, spanning vertically 4.2m between the wind rails. The composite panels, which are insulated, were selected because the cladding falls within an industrial palette of materials. They also have a warranted coating that resists the effects of high winds and salt spray in the coastal location.
The three structural tiers effect a hierarchy of scales revealed as the building is approached, and the perforations in the wind rails create a play of shadows on the facade.
The exposed structural steelwork was sprayed on site with micaceous iron oxide to protect from corrosion. A dark grey colour with a matt finish was used to give definition against the lighter silver colour of the pre-coated cladding panels.
Client States of Jersey Transport and Technical Services Department
Architect Hopkins Architects
Project manager Fichtner Consulting
Executive architect EPR Architects
Contractor Camerons Building Contractors with Spie Batignolles & CNIM
Structure Campbell Reith
Structural steelwork Bourne Steel
Landscape architect Robert Townshend
Profiled cladding Kingspan Gable glazing and curtain walling Technal
Metal flush doors NGF Industrial Doors
Roller shutters Hormann Louvres Levolux