Bam’s office job for Leeds City Council has gone ‘above and beyond’ standard practice to cater for the needs of those with disabilities.
Project: New Merrion House
Client: Town Centre Securities and Leeds City Council (75:25 JV)
Contract value: £42m
Contract type: Design and build
Region: Yorkshire & the Humber
Main contractor: Bam Construct
Demolition subcontractor: Thompsons of Prudhoe
Start date: January 2016
Completion date: January 2018
Built in the 70s, New Merrion House was in need of a major overhaul.
And in an initiative driven by tenant Leeds City Council, it also provided main contractor Bam Construct with the opportunity to think carefully about how it could embrace best practice in disability design and refurbishment.
The project is part refurbishment of the 14-storey Leeds City Council offices and part new-build, with the latter comprising an extension to the front of the existing structure.
Once work to modernise the old building completes, staff from 14 other sites will move into the renovated offices. The new-build is seven storeys high, with a lofty atrium that will rise all the way to the top of the structure. It’s perhaps no surprise that this airy new addition to the council’s site will house its public-facing functions.
“We’ve taken it back all the way to the concrete frame – to a shell – and started again”
Simon Sutcliffe, Bam Construct
For the old building, which was built in 1973, Bam removed the roof and stripped the space so that it could relocate the building’s plant there, with external risers added so ventilation and other services can be redistributed to the floors below.
“It was linear concrete panels and ribbon windows all the way around with single glazing and horrible heating below all the windows,” says Bam Construct construction manager Simon Sutcliffe. “It was awaiting a refit, shall we say.”
Coming out of its shell
“We’ve taken it back all the way to the concrete frame – to a shell – and started again,” he continues. From a construction point of view you could say it’s almost like finishing a concrete frame and carrying on – that’s how much we’ve taken out of it.
“It’s complicated at the lower floors because we’re next to the existing shopping areas and a Morrisons and there’s car parking below that [as well].”
Mr Sutcliffe explains that the new building will tie into the old one at floors two and six, though this is in a connectivity sense via footbridges, rather than for reasons of structural support.
“They are designed as two independent buildings. There are bridge links, but they have movement joints, so in theory the buildings can move independently,” he says.
These joints will facilitate thermal expansion of up to 20 mm, though Mr Sutcliffe is doubtful that it will ever move by this amount.
“We were bringing back the material in trolleys with a little railway track going up the excavation”
Simon Sutcliffe, Bam Construct
He elaborates that wherever the new building abuts the existing one, steel beams on slotted connections allow the two structures to move separately.
“It was a strange one in terms of winning the project as we lost the job initially and it went to Shepherd who were then taken over by Wates,” Mr Sutcliffe says. He explains that this resulted in the client going back to the market, with Bam proving victorious at the second attempt.
With the deal in the bag, Bam began work at the start of 2016, with completion scheduled for early 2018.
Mr Sutcliffe says there was a small-scale enabling works package that ran through until March 2016. That included road closures, moving the footprint of the site into the road to create a working area, and asbestos removal – all very run of the mill.
Then, almost as an afterthought, he mentions something more out of the ordinary.
“We did a tunnelled sewer diversion that was ‘back to traditional’ [construction]. There’s a 600 mm sewer that runs through the middle of the new-build.” He says Yorkshire Water doesn’t appreciate contractors putting new-builds on top of sewers, since it needs full access to its utilities.
This meant the sewer needed to be diverted to the perimeter of the front of the new extension where it forms a dogleg about 100 m long, with depths ranging from 3 m to 5 m.
“Because of the nature of the services that are around the perimeter – such as fibre optics and HV cables – we couldn’t do a traditional cut and fill from the top, so we had to go ‘through’, he says. “We had a 1,200 sq mm excavation with timber sleepers and it was traditionally excavated and taken forward.
Bam Leeds council office 7
“We put a steel former in place and then shunted the pipework along them. You’re restricted; all you’ve got is the shaft you’ve dug for a manhole and you’re digging from one manhole to the next,” Mr Sutcliffe adds, joking that it was like the tunnel in the film Escape to Victory.
“We were bringing back the material in trolleys with a little railway track going up the excavation. It’s all manual work [with the material going] into a little basket on the railway.” These went back to the main shaft where workers could lift them out.
The new-build sits on concrete pad foundations, measuring around 3 sq m, that run in line with the existing structure and bear directly onto the underlying weathered mudstone and then hard rock stratum.
The only occasion that piling was used was for the wall of the original basement excavation. But Mr Sutcliffe says the need for these was negated as the footprint and hence the design of the building evolved.
Designed for inclusion
“There are scooter charging points where people might need to transfer to a wheelchair,” Mr Sutcliffe says. “They come in the building, swipe [for access] and it’s all about planning for how staff can get from A to B.”
He says features such as the strategic positioning of automatic doors have been carefully thought through. “There’s no reason why disabled people can’t open doors manually, but in this scheme the client wants [some] doors to be automatic. I think it’s going beyond [the normal consideration for a building of this kind], you don’t normally have a route that disabled people can follow and every single door would be automatic.”
He explains that regulations dictate the force required to open a door so that less-able people have easier access. “But here the client’s chosen to go down the [route] where it wants automatic doors [or hold-open doors] everywhere,” he says.
Careful consideration has gone into the fire escape routes for less-able workers. “There’s a disabled refuge in the centre of the building with an alarm that buzzes down the stairs so that people know where stranded disabled people are,” Mr Sutcliffe says. “We’ve got evacuation lifts [here] that you don’t have on every job.”
Both buildings feature these lifts that only members of the fire brigade can operate. One difference from a standard lift is a 25 mm ramp that rises to the door. This prevents water from fire hoses cascading down the shaft and interfering with the electrical systems, rendering the lift inoperable.
“There are [also] disabled refuges on the outermost escape stairs at the ends of the building where a disabled person, if they were blocked from getting to the lift lobby, would go to an alarm and the fire brigade can retrieve them from there,” he adds.
There are more everyday accommodations, too. A partially sighted council staff member has advised on differential finishes, with varying light reflectance values dictating colour schemes that will be used throughout the project. This extends to those used in the toilets.
These differentials are planned at points of changing geometry such as the intersection of a floor becoming a wall. Both elements should be at least 30 points apart on the 0-100 LRV scale so that depth perception and spatial awareness can be more accurately gauged by a partially sighted person.
This also applies to, say, surfaces in an office kitchen being different from cupboard doors, those doors to the kitchen walls, and so on.
It’s especially pertinent to projects where spaces become enlarged (walls are removed to create one large office). “With open plan offices, for instance, it’s about being able to assess the volume of the space… to see where the floors finish, where the walls start and where the ceilings are,” Mr Sutcliffe says.
Some of it is easier to implement than it might at first seem. “The long thin parts of the building are glass curtain walling blinds that differentiate themselves anyway, as a certain percentage of windows creates that difference in reflectance. So you’ve got dark carpets, white walls and glass,” he adds.
“There are white ceilings, but they’re differentiated by linear strip lights that change the feel of the ceiling. The end wall of the office will be painted blue to give a difference between the floor and the wall. Partially sighted people can then feel the depth of the room so that it doesn’t feel like it’s going on forever.
“I’ve never built an office – an open plan environment – with those sorts of considerations. Within a kitchen space where you’re designing for partially sighted people I’d expect there to be that differentiation – but how many offices do you go into that are just white walls and white ceilings?”
The new-build also diverges from the old by featuring a steel frame as opposed to a concrete one. Internally, the three structural cores comprise two for lifts and one for stairs. These provide all the structural stability that the steel frame will require.
‘It wants to fall over’
“It’s a bit of a strange shape, it’s trying to fall over onto the road,” Mr Sutcliffe says, a situation not helped by it cantilevering out by about 1.5 m over the pavement. “So they’re doing all the hard work with holding the building up.”
The BREEAM Excellent building will now feature two gas-fired generators in the basement that Leeds City Council, as opposed to the landlord, has decided to install at a cost of about £1.5m. These will feed back into the grid at peak times.
The project is notable for the care taken to accommodate the council’s staff that have disabilities.
“The council is catering for its staff as much as for the public, so there’s been a lot of work done in terms of how people will access the building and all the routes they will take through it,” Mr Sutcliffe says (see box).
In a sense, the building has been something of a chrysalis for enlightened tenant / client Leeds City Council. Not least because the facility that’s emerging is larger than the original, but also because New Merrion House will be set up for those with disabilities in ways that were barely considered when it was built in the early 70s.
And in the latter sense, that’s a commendable achievement.