- Massive value engineering
- Piling and cladding overhaul
- Phantom heads lab
- Post-tensioning pulls tooth facility together
- Steel braces for dentists
A state-of-the-art dental hospital is being built on the site of the former BBC Pebble Mill Studios as part of a new healthcare campus.
Project: Birmingham Dental Hospital & School of Dentistry
Client: Birmingham and Solihull LIFT
Contract value: £36.5m
Region: West Midlands
Main contractor: Galliford Try
There are still signs on the site of the new Birmingham Dental Hospital & School of Dentistry that reveal its previous life.
Difficult to spot they may be, but there are clues that give away its identity as the former site of the BBC studios in leafy Edgbaston, Birmingham.
This was once the site that launched thousands of TV and radio careers including, among others, Jeremy Clarkson’s.
It was a building that was unashamedly of an era. An era of wide-lapelled leather jackets, of Laura Ashley dresses and Triumph Stags.
When the BBC moved out in the mid-2000s the old studios were bulldozed, ready for the site to be redeveloped.
Various schemes were hatched to bring it back into use in the years since then, but it is only the latest plan to develop it as a healthcare campus that has really developed any impetus.
Galliford Try has taken a £36.5m contract that will see it construct a new dental hospital on the site.
This will be the first phase of the plan to bring in other healthcare operations to create the campus and will replace the existing Birmingham Dental Hospital, which currently occupies ageing facilities in the city centre.
The new centre will also provide a base for the School of Dentistry from the nearby University of Birmingham.
Project manager John McCabe is looking to ensure the facility opens in time to help school the next batch of student dentists this autumn.
Massive value engineering
Awarded after a two-stage tender, the first interview took place in March 2012.
“We knew we needed to maintain the dental elements of the scheme, so we looked at alternative areas where we could trim costs back”
John McCabe, Galliford Try
While the team reached financial close in August 2013, the scheme had to go through a massive value engineering process before the deal could be done.
“Basically the initial design just wasn’t affordable,” Mr McCabe says.
“We had to drive through a significant value engineering process to make it so. We knew we needed to maintain the dental elements of the scheme so we looked at alternative areas where we could trim costs back.”
There was no one specific area where the team made significant cost savings. Instead, small gains were made across the scheme to make it more affordable for the client.
“We went to our supply chain and asked them what they could do,” Mr McCabe explains.
“Thankfully we have a mature supply chain and they were able to come back to us with a whole raft of efficiencies.”
Piling and cladding overhaul
A rethink that saw the team opt for a bespoke piling layout and an alternative cladding system was among the steps taken to reduce cost.
The team needed the cladding to deliver the high level of insulation required and the appearance specified through the planning process.
In the end, recommendations made by subcontractor Richardson Roofing led to the select of the Qbiss system by manufacturer Trimo, specifically the Qbiss One BF horizontal and vertical panels.
These helped deliver some of the cost savings the team was looking for while still providing the level of insulation demanded.
The pile design has also been altered significantly.
Initially there had been a plan to install single diameter, standard piles with a similar pile caps across the site.
This has been changed to a much more tailored design, with different 300 mm and 400 mm-diameter driven piles at depths of 12 m or 16 m.
“The design does have some augured piles around a Severn Trent main foul sewer that runs along the southern boundary of the site, and there are a few steel piles where the base slab is in tension,” Mr McCabe says.
By using the bespoke design and driven piles, the team was able to rack up savings through a reduction in material costs thanks to a different rebar configuration, as well as efficiency savings through using a single rig.
“We over-cut the site down to piling platform level – as much as 4 m on the south side where we have the undercroft car park – then backfilled and piled the higher end as well as the retaining wall,” Mr McCabe explains.
The building is split into the north and south blocks linked by a glazed atrium.
Ground, first, second and third floors will be occupied by the hospital, while plant rooms are located on its fourth floor.
Phantom heads lab
It is the North Block that accommodates the ‘phantom head’ laboratories.
Here dummy heads are linked up to computers to allow the next generation of dentists to practice their teeth-pulling techniques without inflicting any pain on innocent members of the public.
But top-notch facilities like these require masses of input on the mechanical and electrical side of the contract.
Most projects would expect to see an M&E budget of between 20 and 25 per cent of the total cost.
“Each of the 154 dentist chairs need suction, compressed air, drainage, water, electrical power supply, data cables and rinsing water”
John McCabe, Galliford Try
Here at the Birmingham Dental Hospital, that rises to more than 30 per cent, according to Mr McCabe.
“There is a very high M&E content here,” he says. “The building is designed to be very clever and energy efficient.
“We have gas/solar thermal hybrid boilers that will run off solar during the summer.
“Couple that with the amount of services for the phantom head labs, the different chemicals and various gases that are used.
“Then, think that to each of the 154 functioning dentist chairs here we have to supply suction, compressed air, drainage, water, electrical power supply, data cables, rinsing water as well, then it becomes very complicated.”
The amalgam facility – which sifts and reclaims all the tiny pieces of the amalgam alloy used for fillings swilled away by patients – is another unusual addition to the steel-framed plant rooms on the building’s top floors.
Fortunately, some of the more mundane main runs and risers have been prefabricated in sections off site.
“It’s a complex building,” Mr McCabe says. “It’s an intricate and very challenging build, but it will be a fantastic facility for the people of Birmingham.”
Post-tensioning pulls tooth facility together
Galliford Try is installing a reinforced concrete frame coupled with post-tensioned slabs at the new facility.
The design is intended to make the most efficient use of concrete’s thermal mass and the larger spans and slimmer slab thicknesses offered by the post-tensioning solution.
The building is based on a 5.6 m grid, but across it there are slab spans of more than 10 m.
By using the post-tensioning method, the team has managed to maximise those spans, keep the headroom thanks to the slim 300 mm-thick slab and still keep the flat soffit the client wanted.
“It was always going to be a concrete-framed solution,” Mr McCabe explains.
“There were some initial thoughts on using precast concrete planks, but we came up with the post-tensioning method.
“We were of the view that it would be a better cost option without affecting the buildability, integrity or final suitability of the building.
“It is quicker, there is less rebar and less concrete so it saves in both programme and material costs.”
The team used a standard C40 mix concrete from supplier Cemex for all the concrete elements and pumped the slabs on a six-pour, two-week rotation.
“A typical floor has three slab pours on the South Block and three on the North Block,” Mr McCabe adds.
“We were trying to turn around a floor to floor every four weeks.”
Steel braces for dentists
Concrete may be the order of the day for most of the structure, but across the upper two floors of the North Block the wide spans needed across a kitchen area at level two meant the team needed even wider spans than a post-tensioned slab could offer.
At levels three and four, the team has installed five 16 m-long, 1,200 mm-deep steel trusses that help provide the span dimensions needed.
The trusses protrude through the soffits of the slab, leaving them open so that the building can benefit from the concrete’s thermal mass, while services are strung through and around their sections.