好色先生TV

When architect Aston Webb devised the University of Birmingham鈥檚 masterplan in 1900, it is unlikely that he thought it would take 112 years to finish. Webb came up with a plan consisting of a grand semi-circle of five linked pavilions arranged around an enormous Italianate clock tower. Academic facilities would be housed in the pavilions, with the clock tower forming the grand centrepiece of the scheme. The tower and four of the pavilions were built, but then the 拢250,000 budget ran out.

Despite the university鈥檚 relentless expansion since 1900, the grand semi-circle of pavilions has always been left looking like a model鈥檚 mouth with a tooth missing. Now, more than a century later, a generous donation from Birmingham alumnus and former chairman of social housingconstruction firm Keepmoat, Terry Bramall, has allowed the gap to be filled. The 拢16m Bramall Music 好色先生TV, designed by Glenn Howells Architects, will house a 450-seat auditorium, music practice rooms and offices.

Because Webb鈥檚 semi-circle is grade II*-listed, the new music school had to match the existing red brick buildings. Built by contractor Bam, the project is a fascinating showcase of how construction techniques have changed over the last 100 years, and how state-of-the-art music facilities can be combined with traditional architecture.

Webb invested considerable architectural firepower in the original neo-Byzantine pavilions. The largest, the Great Hall, which sits in the middle of the semi-circle, had to be sufficiently impressive to persuade King Edward VII that it was worth his while to trail all the way up to Birmingham to open the new university in 1909. The other three pavilions are stylistically similar, although smaller. Each is capped by a lead-clad dome, lashings of natural stone break up the brickwork and a frieze adorns the front of each link building.

The brief prevented Glenn Howells from simply copying the other pavilions. The auditorium will be used for public concerts so access was needed though the front of the building. The only pavilion with an entrance at the front is the Great Hall, so this approach has been adopted for the Bramall Music 好色先生TV. The auditorium is located behind the link, but wouldn鈥檛 fit into the same volume as the existing pavilions. 鈥淢uch as we tried, we couldn鈥檛 get the auditorium to work acoustically within the existing T block shape so we have had to reinvent this at the back,鈥� explains project architect Will Schofield.

The new and original buildings look fundamentally the same. Not that it was simply a case of dusting down some 100-year-old construction manuals 鈥�

The frame

How it was done in 1900

The existing buildings are a mix of old and, for 1900, new construction techniques. The Great Hall incorporates a steel frame to cope with the large internal spans. The brickwork is self-supporting so is independent of the frame.

The smaller pavilions are mostly constructed from loadbearing masonry with 700mm-thick walls. Open-plan spaces have been created on the upper levels of the T blocks by using steel roof trusses.

How it is being done today

Load-bearing masonry would have been prohibitively expensive and would not have met the brief. The only way of achieving the 20m spans in the auditorium is to use a steel frame, which is similar to the approach adopted for the Great Hall. Plant and music practice rooms are housed in the basement, so a concrete frame has been used
here for acoustic reasons.

The brickwork

How it was done in 1900

The buildings were built using a very hard engineering brick called Accrington NORI. This was a non-standard size, longer and thinner, probably because this evoked the Byzantine style. Brick was also a good way of making the most of the original limited budget.

How it is being done today

Recreating the original brickwork has been one of the major challenges of this job. The easiest solution was going back to Accrington and simply using the same bricks, but halfway through planning, owner Hanson decided to close the brickworks down. 鈥淲e enquired about reopening it but the cost per brick was prohibitive,鈥� explains Bam鈥檚 project director Scott Marsh. Instead, one of Bam鈥檚 existing brick suppliers is making the bricks to the original dimensions.

But architect, contractor and planners couldn鈥檛 agree how many colours had been used on the original buildings. 鈥淚t was getting very close to holding us up and was making us very nervous,鈥� says Marsh. 鈥淚t was too important to get wrong,鈥� retorts architect Schofield.

Eventually the team settled on three colours from two bricks. One was fired for two different lengths of time, which changes the colour. Sample panels were made up - eventually the planners agreed the blend of bricks used on the important north elevation facing the clock tower would be used for the rest of the new building.

The pointing

How it was done in 1900

A cement-based mortar was used for the original building. The bricklayers probably pointed the brickwork without thinking about it too much, then went home.

How it is being done today

Marsh describes recreating the pointing as 鈥渉orrible鈥�. Today鈥檚 bricklayers are used to applying mortar to standard 10mm-wide joints and finishing them with a simple flourish of the pointing trowel, which gives a neat, smooth finish. But for the Bramall Music 好色先生TV, Bam鈥檚 team had to mirror precisely the colour, shape and finish of their Edwardian forebears鈥� work.

The horizontal joints in the original buildings were 13.5mm wide and had a coarse finish that the team tried to match using a mix of coarse (sharp) and fine (building) sand. Dyes weren鈥檛 allowed either. A special tool was made up to drag the joint to the right shape and finish. 鈥淲e found the sand was too coarse so when you dragged the joint it looked too rough,鈥� explains Marsh. 鈥淗aving gone through all that we ended up with a standard building sand.鈥�

He adds that the process was made more tortuous as the planners had to sign off the finish. 鈥淵ou don鈥檛 phone them up and they come down - you might have to wait two weeks for them to check your pointing,鈥� he says. 鈥淭hey ask for a change, then you have to wait another week for them to come back. It was very frustrating.鈥�

challenge was ensuring that the pointing was consistent over the whole job. 鈥淲e were concerned that we have different people doing the pointing, and the finish varies depending on how much pressure you put on the tool,鈥� says Marsh. Bam ended up getting just two to three people to point the building, which made the job very slow. Marsh says that the brickword alone has taken a year: 鈥淚t鈥檚 almost scandalous how long it鈥檚 taken,鈥� he sighs.

The programme

How it was done in 1900

The original buildings took seven years to construct. Although the job consisted of four pavilions, link buildings and the clock tower, that is still leisurely by modern standards.

How it is being done today

The construction programme for the Bramall building is 96 weeks. This should have been easily achievable, but matching the appearance of the original buildings has been a time-consuming process. Marsh has resorted to modern methods of construction in a bid to claw back time, specifically for the brickwork. 鈥淭he logistics of servicing all those brick layers would have been a nightmare,鈥� he says. 鈥淓arly on we established we had a problem getting the auditorium finished on time.鈥�

The auditorium is large and windowless, so Bam took the decision to use precast panels for this part of the job. Precast concrete panels are faced with brick and fixed to the steel frame. The specially made bricks are sent to a specialist to be cut into slips, then on to precast specialist Techrete ready for fixing to the concrete panel.
One bricklayer has done all the brickwork and pointing to keep it looking consistent. 鈥淭he guy in the factory in Doncaster has had to create exactly the same finish as the guy on site in Birmingham up on scaffolding,鈥� says Marsh.

Precast panels are being used for the inside skin of the auditorium walls rather than 300mm-thick blockwork. Precast panels, 180mm thick, offer the same acoustic performance and the smooth surface means the oak strips used as the interior finish are quicker to fit, as there are fewer gaps to fill behind them - an acoustics requirement.

Marsh says this solution has saved 12 weeks on the programme. 鈥淕oing for precast was our finest hour,鈥� he beams.

The stonework

How it was done in 1900

Stone bands in the brickwork add visual interest, and there are stone cornices and windows. The stone was sourced from Darley Dale in Derbyshire and would have been delivered to site in blocks. Stonemasons would have carved the stone on site without drawings.

How it is being done today

The Darley Dale quarry is closed but a Johnsons Wellfield York Stone matched it perfectly, making it the easiest material for all parties to agree on. The stone profiles were drawn up and sent to Johnsons Wellfield to be cut, rather than being done on site. 鈥淲e are not in that era any more,鈥� says Schofield. 鈥淧eople want to know who is responsible if there is a problem. If the stonework is wrong, that is because it is drawn wrong.鈥�

The stone is delivered to site and hoisted up onto the scaffolding, which is carpeted to avoid the blocks getting chipped. The stone is put into wheeled bogies and moved to the right location, then fixed to the building. 鈥淚n 100 years we haven鈥檛 come up with a better way of doing stone, except for the design work upfront,鈥� says Marsh.

The dome

How it was done in 1900

The frame was made from iron plates riveted together. Marsh thinks the dome frame was made on the ground and lifted into position as one unit. Timber boards were laid over the frame as a base for the lead cladding. The domes at Birmingham feature a layer of concrete over the timber, possibly to provide a smoother base for
the lead.

How it is being done today

According to Schofield and Marsh, this is the biggest dome to be built in 60 years. It is almost identical in construction to the original but with the addition of insulation.
It is made from a steel frame consisting of 24 curved segments linked by secondary members. A temporary platform was erected and used to position four segments at 90潞 to each other and the compression ring linking these at the top. The rest of the segments were added, then a vapour control layer. Lengths of 2鈥� x 2鈥� timber were stacked in strips on top to create the necessary depth for mineral wool insulation, followed by a waterproof membrane.

The timber boards were laid next. Marsh says these needed to be at 45潞 to the lead strips, which took a lot of planning. Fortunately the work was being done during a prolonged dry spell. The mop sticks - rounded strips of wood used to create raised seams for the lead - were fixed over the timber, but then Marsh realised he had a problem. The boards were beginning to curl slightly, which happens naturally but had been speeded up by the hot weather. Timber always curls in the opposite direction to growth rings so the trick is to fix the boards so that the edges press downwards and the middle lifts up. Unfortunately, Marsh noticed, many of the boards had been laid the other way up, which created a sharp lip that would wear the lead prematurely.

Marsh was faced with a dilemma. 鈥淚t would have been very easy to tell the leadworkers to lay the lead over the top, as we wouldn鈥檛 have had a problem in the defects period,鈥� he says. 鈥淲e decided it had to be done properly so Bam took the brave decision to take off the mop sticks and put another layer of timber on top, this time
the right way round.鈥�

Then the lead could be laid over the top, a process unchanged in 100 years. A cupola was built off site and craned into position on top of the dome.

The interior fit-out

How it was done in 1900

The solid masonry walls would have been plastered traditionally. The windows are leaded lights fitted between stone mullions. There is a vaulted ceiling over a corridor running the length of the link buildings; this features a timber framework with wooden laths coated with plaster.

How it is being done today

Modern fit-out techniques have been used, including drylining for walls and partitions.

Double-glazing has been used for the windows, and the mullions have been omitted, which gives the building a less fussy look. 鈥淲e could never have achieved Part L with a single-glazing system or justified the additional energy use to the university,鈥� says Schofield.

The vaulted ceiling has been made using glass-reinforced gypsum attached to a metal frame. Marsh said he had to wait months to get a particularly experienced craftsman to make this ceiling. 鈥淗e鈥檚 worked for the same company for 62 years, 鈥� explains Marsh. 鈥淗e calls the draughtsman the 鈥榶oung lad鈥� and he鈥檚 85.鈥�

The auditorium is suitably high-tech with an orchestra lift, flexible seating and 4m-deep roof trusses, which allow plenty of room for lighting and other technical equipment. The building opens in March and completes the original masterplan. Aston Webb would have been proud.