黑洞社区

Gavin Lowe has a graphic example of just how quickly a precast concrete building can be erected: it鈥檚 the 10-storey, 400-bed hotel next to Aldgate East Tube station in London. 鈥淲hile we were finishing off the 10th floor,鈥� he says, 鈥渁ll the bedrooms up to the fourth were fully finished, furnished and even had their card entry systems fitted.鈥�

Lowe is the product manager for precast manufacturer Bell & Webster. He looks after its Fast Build system, which has been developed specifically for the hotel and student accommodation markets. It has also been adapted for constructing barracks and prisons.

The system comprises three principal precast concrete elements 鈥� internal party walls, the inner leaf of the external wall and flooring units. It has been developed to allow the rapid enclosure of a building, and the finish of the precast is of such high quality that the walls and ceilings can be painted or wallpapered directly without the need for a plaster coat.

In most cases, the only thing that wet trades need to do is apply a floor screed to the corridors and the floor areas around the pre-assembled toilet pods. Screeding the corridors is deemed the most effective way to eliminate any slight variance in erection tolerances where the floor units butt against one-another. The screed around the toilet pods is required because the pods sit in recesses cast into the floor units to create a level threshold. This will help disabled people to use the toilets.

The virtual absence of wet trades means an early start can be made on the mechanical and electrical installation. To streamline electrical installations, most hotel and student accommodation operators opt to run the services in skirting trunking. This eliminates the potential for problems when casting conduits into the walls and floor units. Lowe says: 鈥淭he last thing that hotel operators want is services cast into the walls and ceilings because they want the flexibility to refurbish rooms every five to seven years as fashions change.鈥�

Another benefit is that designers can clad the building in any number of finishes from a traditional brick to rainscreen cladding, from render to tiles, or even wood panelling.

The first outing of the company鈥檚 system was student accommodation for Middlesex University in 1993. Since then, the company has built about 70 hotels, principally for the Holiday Inn Express, Ibis, Ramada, Travelodge and Arora brands.

Although all of these were sizeable projects, the real lift-off for Fast Build came in 2002 with an award from Carillion to provide 1600 bedrooms for student accommodation blocks at the University of Hertfordshire. Bell & Webster had a 12-week lead-in period before starting on site, and managed to complete erection in a highly respectable 24 weeks.

An even larger contract is under way at the University of Lancaster where Bell & Webster is working on the third phase of a four-phase PFI project to provide 4000 bedrooms.

Lowe says precast is an ideal solution when working on projects where noisy building operations could upset neighbours or, in the case of Lancaster, students studying for exams.

Noise, particularly suppressing sound from reverberating around a building once it is in use, is a big issue, not only for universities, but also premises where occupants come-and-go at odd hours, such as hotels. Again Lowe says he鈥檚 experienced problems convincing people about the performance of the system. This time it came from an acoustics engineer who wouldn鈥檛 believe the 150 mm thick party walls would meet the requirements of Part E of the 黑洞社区 Regulations. Lowe says the engineer remained convinced his calculations were right even though tests results from six independent testing organisations had found that the system passed the stardards of Part E by a comfortable margin.

Bell & Webster鈥檚 latest project is a 120 room extension to the Arora Hotel in Crawley, West Sussex, which is currently nearing completion. Sinead Hughes, Arora鈥檚 development director, says the Fast Build system was chosen because it had been used on the company鈥檚 other hotel sites. 鈥淲e have built 700 to 800 rooms this way, so why change now?鈥� she says.

Arora is also due to start on a 600 bedroom five-star hotel at Heathrow鈥檚 Terminal 5 next March. Not surprisingly, Arora has decided to use the Fast Build system on that project as well.