The Crown Estate called on GKR Scaffolding to work day and night above tens of thousands of shoppers and busy London traffic to redevelop a Grade II-listed building.
Regent Street is one of London’s most famous tourist destinations, receiving more than 7.5m visitors every year.
The Crown Estate manages Regent Street’s 2 km of shop frontage and is now over halfway through a £1bn investment programme to upgrade the buildings and the public realm surrounding them.
One component of this investment is the project to rebuild the structure occupying block W5 of Regent Street, now known as One New Burlington Place, developed by Crown Estate in joint venture with Exemplar and designed by Alfred Hall Monaghan Morris.
Mace acted as main contractor on the scheme, which came with the extra challenge of retaining and restoring its existing Grade II-listed façade.
The site occupies the corner of Regent Street and New Burlington Street, with two listed buildings on the latter road also redeveloped for a mix of commercial and retail use.
Mirror project lessons
GKR Scaffolding helped to facilitate the complex works required, having worked with Mace previously on the almost mirror-image project at block W4, just across the street from One New Burlington Place.
The W4 project, 10 New Burlington Street, was completed in early 2014 and provided 33,000 sq ft of retail space and 97,000 sq ft of office space.
Regent Street GKR Scaffolding Crown Estate 3
“We partner with Mace quite a bit,” says GKR Scaffolding associate director Tony Lane. “We’d finished W4 so we had the experience that was required. We were successful through competitive tender and then spent three to four months planning early doors, taking the lessons learned from W4.”
The project saw the team retain the Portland stone façade along Regent Street, as well as part of the way down New Burlington Street. Mace then demolished the entire building down to basement level before bringing it back up floor by floor.
More on Working at Height
GKR started on site as long ago as August 2012. “The initial phase of works was a full external scaffold around the building,” Mr Lane explains. “We were involved prior to the works being carried out to build the gantry and façade scaffold, to allow for the façade retention to be installed. We then went away for about a year as the demolition went on.”
“We looked at the risk of falling materials and decided night-working was the best way to alleviate this”
Tony Lane, GKR Scaffolding
Once the new floor slabs were constructed, GKR removed the external scaffold and then installed a cantilever out from the fourth-floor level. This was to allow low-level areas to be handed over to client for retail fit-out prior to work commencing on the high-level mansard roof and Portland stone façade restoration.
“We cantilevered up and bridged over the roof to hang down,” Mr Lane says. “That was made up predominantly of Apollo 750 mm X-beams, with more than 90 lines of beams required. We got a lot of strength out of those beams, and using them reduced the number we would have required if we’d gone with an alternative beam.”
The biggest challenge for GKR’s team was the site location. This area of Regent Street sees well over 10,000 pedestrians move along the pavement every hour, not to mention the extremely busy road. To manage the risk, GKR opted to install the cantilever overnight.
“Although we have a full tethered policy, we looked at the risk of falling materials and decided night-working was the best way to alleviate this,” Mr Lane says. “That meant the work took place from 11pm to 6am, Monday to Thursday, which allowed us to get permission from Westminster City Council to close the pavement off in its entirety.”
Regent Street GKR Scaffolding Crown Estate 5
The works took place over a four-week period and the closure meant the team could erect a much bigger exclusion zone than might otherwise have been possible. “We were able to put the cantilever in, cover and board that, and then seal it completely with an 18 mm anti-slip buffer board up tight to the building, so there we no gaps at all.”
GKR also received permission to close a bus lane at certain times, allowing it to park a vehicle at the side of the road and barrier it off from traffic. “We could then work directly from that vehicle onto the low-level areas,” Mr Lane says.
With the cantilever now sealed off, the team felt comfortable in moving the works back to the daytime, extending the scaffold up to roof level during normal working hours of 8am to 6pm, Monday to Friday, over five weeks.
“All the materials were moved up onto the roof by crane and accessed from there, with everything tethered”
Tony Lane, GKR Scaffolding
With the risk of falling materials again in mind, GKR decided to use its in-house Elimin8 tethering system with all components and tools during the installation and removal of the complex scaffold (see box).
“All the materials were moved up onto the roof by crane and accessed from there, with everything tethered,” Mr Lane says. Even the Monarflex sheeting was pre-rolled on the roof before installation so that no loose bunches were found on the scaffold itself.
GKR was able to work out of a loading bay on New Burlington Street, a one-way street which was half-closed by Westminster City Council for the contractors’ use.
“It enabled lorries to come in and go away, meaning there was no congestion on Regent Street,” Mr Lane says. “We had room for two to three lorries at a time too and loaded the tower crane up from there.”
The team then worked in reverse to dismantle the scaffold, working during the daytime first before more night work to take down the cantilever. The final section was taken down in August last year, but the retail fit-out is still ongoing, with Michael Kors and Ralph Lauren both set to open flagship stores soon.
The end value of the project will be in the region of £1m for GKR, which hopes to continue working for Crown Estate on more projects in its major redevelopment of its portfolio.
“We’re always looking to develop and learn from our experiences, and venture into different areas,” Mr Lane says.
“The biggest challenge here was definitely the location – it just needed lots of planning to foresee what was required.”
The Elimin8 system was developed by GKR Scaffolding five years ago, and played a role in the firm winning the award for Access & Scaffolding Specialist of the Year at the Construction News Specialists Awards 2016.
The company worked with Loughton Scaffold Suppliers to develop a new tethered scaffold fitting, which enables main scaffold fittings to be tethered until they are securely fixed.
The specialist also took the unusual step of not patenting the system – deciding instead to encourage other firms both within the scaffolding sector and in the wider industry to use and benefit from it.
The One New Burlington Place project on Regent Street was carried out successfully with no incidences of falling materials.