Ensuring the shows go on and scheduling around the toilets are among the obstacles construction manager Rise is tackling on this high-profile refurbishment.
Client: Royal Opera House
Contract value: £27m
Project value: £50m
Construction manager: Rise Management Consulting
Consultant: Gardiner & Theobald
M&E subcontractor: Arup
Start date: January 2015
Completion date: March 2018
Deep in the basement of London’s Royal Opera House (ROH) there is an almighty racket going on. And there’s nothing operatic about it.
Concrete breakers and jackhammers are ripping out sections of the old structure, which is being reconfigured as part of a £50m revamp of Covent Garden’s cultural icon. But none of this noise can be heard in the auditorium and rehearsal rooms above.
“It was a central requirement of the project that the whole of the ROH could continue to operate as normal throughout the works,” says Joe Hacke, principal at Rise, construction manager for the scheme. To prove the point, he takes CN through the ROH back-of-house areas, where the serene sounds of rehearsals waft through – but not a sound from the construction work is audible.
This refurbishment is a largely “unseen project”, as Mr Hacke puts it, with the work concentrated in the building’s lower levels.
Apart from the hoardings on Bow Street and the temporary closure of the Covent Garden piazza entrance, visitors would barely notice there is a construction project under way. Any internal interfaces are screened off, with dust sheeting and acoustic blankets used where necessary.
Send for the manager
Unseen it may be, but this is a highly complicated job (see box). The project aims to improve access and bring more natural light into the ROH, which means major structural alterations involving some 53 tonnes of steelwork. This complexity, plus a few uncertainties over scope, persuaded the client to appoint a fee-based construction manager to run the project rather than awarding a lump-sum contract.
“If we have to shut off the water at any point, we run the risk of cutting off the supply for half the building”
Joe Hacke, Rise
Rise started on site in January 2015. The ROH has daily performance schedules that are planned five years in advance, which has helped Rise plan its programme. “We could identify periods when noisy works would be permissible, and these were built into our trade contracts,” Mr Hacke explains.
“However, we keep in constant communication with the ROH and sometimes need to change our work plans on a real-time basis. Noise and vibration sensors have been dotted around the building, and there is a schedule of acceptable limits that has been created by acoustic engineers for different areas of the building.
“We operate a traffic light system, where green means it is ok to make as much noise as is necessary, which is generally before 10am. During rehearsals in the afternoon and performances in the evening, the traffic light goes to red.”
Royal Opera House Rise Main foyer void
Another crucial issue for Rise is the building services. The M&E works account for some £5m out of the project’s £27m construction value and pose problems where they interface with the operational areas of the ROH.
“A running theme on the project is a lack of as-built data from the 1990s extension, and although we have the original designs, things aren’t quite as they appear on the drawings,” Mr Hacke says.
“There are cables running everywhere for audio and broadcasting. We uncovered a high-voltage cable that was not documented when we excavated the Bow Street extension foundations. If we have to shut off the water at any point, we run the risk of cutting off the supply for half the building. So we had to carry out extensive building services surveys before starting any work.”
Bog standard schedule
Curiously, the sequence of work has been planned around the toilets, which are being mostly relocated to the basement to create more space in the foyer. “However, because the ROH is remaining operational and the toilets obviously have to be available for performances, this dictated that we would have to build the 33 new toilets in the basement before we could take out the existing ones,” Mr Hacke explains.
The bulk of Rise’s work is below the main auditorium, which is confusingly called level S0, even though it is effectively the ROH’s first floor. Other floors are named according to whether they are above or below this level, so the foyer at ground-floor level is S-1 and the new basement toilets are at S-2.
Royal Opera House Rise MandE works in the basement toilets
Access from S-1 to the toilets below will be via a new staircase, built from structural steel. Above S-1, another staircase will provide access from the foyer to the glass-vaulted Paul Hamlyn Hall at level S0 and to the escalator that connects with the upper amphitheatre level of the ROH.
“The floor slabs have required major structural alterations to accommodate the staircase down to the toilets,” Mr Hacke adds. “It required around 10 tonnes of structural steelwork, but because of our access restrictions, this had to be brought into the ROH in sections that could be manhandled and spliced together.”
The S-2 toilets replace a former dining area in what was the old foundation structure of the 1858 building. These elegant brick arches will be covered up by plasterboard in the revamp. A new reinforced concrete floor slab has been constructed at this level, which is mostly ground-bearing apart from six 450 mm CFA piles. “We had originally planned for four 600 mm piles but we couldn’t get a big enough rig into such a confined space,” Mr Hacke says.
The most substantial structural works are in the Linbury Theatre, which is closed for most of the project. Constructed as part of the 1990s revamp and sitting mainly below ground with its floor at level S-3, the theatre will be completely updated. The interior is being stripped back to the bare concrete walls and a new seating configuration installed along with more modern audience facilities.
“We have a 23-tonne articulated lorry lift here, but it can only be used 6-8am and 6-8pm. It is a tight job logistically”
Joe Hacke, Rise
During CN’s visit, much of the Linbury Theatre’s existing concrete structure was being broken out by a team of workers in the 4 m-deep orchestra pit. It will be rebuilt with some 29 tonnes of structural steel to support the new, modern auditorium, though planning this element of work has caused several logistical headaches.
“The load restrictions on the floor slab are quite low and the metal bearings in the orchestra area are heavily corroded, so this affects the weight of the plant we can use,” Mr Hacke explains. “The plan is to use spider cranes to remove the existing structure and install the new steelwork, though we will need birdcage scaffolding to get up to the roof which is 11 m high. However, we will also need a hoist and will have to work out how much loading the floor can support.”
Royal Opera House Rise Removing old structure in Limbury Theatre 2
The Linbury foyer will become a much bigger, airier space with bar and catering facilities. Three existing concrete piers, and the reinforced concrete walls between them, have already been ripped out and replaced by 16 m steel transfer trusses. “These trusses each come in three sections; we have had to thread them through the existing structure then bolt them together before lifting into position,” Mr Hacke says.
Sewer adds twist to extra light
The foyer will also benefit from the daylight flooding into the ROH from the new, glazed Bow Street extension above. This has required excavation down to a depth of 4.5 m in an area approximately 5 m wide and 30 m long behind the Bow Street hoardings. Existing piles from the 1990s extension have been broken out and a new wall of 33 secant piles, each 1,000 mm in diameter, has been installed.
This was complicated by the presence of a live, 350 mm-diameter sewer running across a corner of the site. “We had to leave a gap in the piled wall of 1 m on either side of the sewer pipe, which we then infilled with reinforced panels,” Mr Hacke explains. “It is a combined sewer, so in case of damage during the works, we have had to put in a temporary sewage tank.”
Royal Opera House Rise Groundworks for Bow St extension showing old piles
Bow Street is also the main access point for materials. “We have a 23-tonne articulated lorry lift here, but it can only be used 6-8am and 6-8pm. Otherwise, we have to bring materials in and out by hand, or use a a small goods lift. It is a tight job logistically.”
The project, which will have 110 site workers on site at peak, is now just over half way towards completion. The original finish date was September 2017, but this has since moved back to March 2018. “We had a hold-up of nearly 10 weeks due to a review over whether to remove the piers in the Linbury Foyer,” Mr Hacke recalls. “The client also had to delay handing over the main foyer for operational reasons.”
This, he argues, shows the flexibility of the construction management approach. “We have worked hard to save the client costs where possible. A new plant room was planned at level S+4 which would have cost £1.7m, but the architect reworked the interior layout so that the existing air-handling units could be retained.
“A fixed-price job could run out of control here. But although we have had slippage in the programme, Rise’s costs are running under budget.”
Past and present developments
The current Royal Opera House – home of the Royal Opera, the Royal Ballet, and the Orchestra of the Royal Opera House – is the third theatre on the Covent Garden site.
The Grade I-listed façade, foyer and 2,256-seat auditorium date from 1858, after fires in 1808 and 1856 destroyed the previous theatres. Almost every other element of the present complex dates from an extensive reconstruction in the 1990s. These elements are the focus of the current redevelopment.
At ground-floor level, the foyer is being enlarged by around 50 per cent, with better links to the Linbury Studio Theatre. A glazed extension on the Bow Street side will include a new external terrace on the roof, connected to the glass-vaulted Paul Hamlyn Hall – once part of the Covent Garden flower market.
A staircase will be added between the main foyer and Paul Hamlyn Hall, and the entrances on both the piazza and Bow Street sides of the opera house are being replaced to improve street level public areas. The Linbury Studio Theatre and Clore Studio will be refurbished with improved audience and technical facilities.
A later phase, valued at £6m but not yet signed off, involves glazing part of the terrace overlooking the Covent Garden Piazza at Amphitheatre level, to increase restaurant capacity.