The use of a raised access floor still provides the most efficient location to route power and data services, because it allows easier access and greater freedom for space planning when spaces are reconfigured.
Increasingly, clients are demanding less hierarchical and more flexible environments that can cater for present and future use, and technology is advancing and responding to the needs of these clients.
The future, it seems, is heading towards wireless technology; this allows greater freedom for hot-desking and touchdown spaces because laptop computers can operate anywhere within range of a receiver. Wireless technology does not currently provide the safety, speed and efficiency needed for all organisations but, where it does, the reduction in cabling will mean that the 150mm deep void below the floor could reduce considerably. There will then be questions about the cost effectiveness of installing such a deep floor for power distribution only.
The requirement for power sockets - and perhaps some IT/telecoms cabling - will remain, but the depth could be reduced to about 60mm, freeing up 90mm per floor in a new building. This would offer considerable cost savings, especially when looking at the number of tall buildings now in planning.
For example, the 80-storey London Bridge Tower could theoretically save more than 7m in height or include a further two storeys.
Low-height cable management systems, such as that by Intercell, can be seen as a response to these changes. The compact nature of the Intercell system also allows greater scope for installing raised access floors in existing buildings with low storey heights built in the 1960s and '70s, which often remain unoccupied because of their inflexibility. The new Harmonised European Standard for raised access floors (BS EN 12825) allows greater freedom for specification. Where the old PSA MOB standard had four different classifications, the new standard provides more than 70 different classifications for safety load and deflection.
New product design is also developing to satisfy client demands for fashionable hard floor finishes such as timber, stone and rubber. There are now a number of companies providing systems, such as Kingspan, where finishes can be either pre-bonded within a steel tray or gravity-laid on a grid over an existing raised floor. In new-build projects, where the raised floor is normally a construction platform for other trades, the late installation of the floor finish can avoid the need for a temporary 'slave floor'.
Something in the air Requirements for traditional, suspended ceilings are changing as a result of the move away from fan-driven air conditioning to more environmentally sustainable solutions, such as natural ventilation and mixed-mode solutions, including chilled beams and the use of exposed concrete soffits.
These solutions do not require ductwork to be concealed across the entire ceiling and can be restricted to localised service zones, which often follow the principal circulation routes. Nevertheless, the requirement for good acoustics in office environments, together with regulatory drivers such as those required by the changes to Part E (which requires sound absorption in residential buildings), and the recent publication of BB93 demanding higher standards of acoustic performance in schools and education buildings, may be satisfied by the provision of a suspended ceiling.
In residential developments, all communal areas need to be provided with sound-absorbent ceilings. This not only improves the acoustics but also creates an improved ambiance within these spaces, making them feel more luxurious.
Educational sector In the educational sector, research has shown that a good acoustic environment can be created by optimising the ceiling layout to ensure that speech reaches the same level of intelligibility at the back of the classroom as it does at the front. Studies showed that this greatly improved children's learning ability as well as relieving the strain on the teachers' voice. New products, such as British Gypsum's Acteco Rigitone boards, provide an attractive perforated appearance with very good sound absorption, giving a noise reduction coefficient (NRC) of up to 0.9.
Increasingly, there is a role for easy-clean ceilings in both culinary and medical environments, as pressure mounts to prevent the spread of infections such as MRSA and Legionnaires' Disease. British Gypsum's Gyprex Bio tile consists of a gypsum board with a wipe-clean PVC facing. The facing is impregnated with biocide chemicals that provide protection for the life of the tile.
However, the design of such ceilings needs to be considered carefully to maximise the size of the tiles and minimise the number of joints, because the grid between the tiles and the trim to the wall could still harbour unseen germs and dust. Nothing should detract from a thorough cleaning regime.
Cooled ceiling systems have advantages over traditional air conditioning within hospitals because they reduce the risk of infection through the movement of air. Systems such as that manufactured by Hunter Douglas have the added advantage of being completely silent in operation, and use a continuous polypropylene pipe to circulate water at 16°C. The ceiling tiles can be hinged down for cleaning, while the pipe work is retained in a separate carrier system.
Easy maintenance access to the service zone above suspended ceilings is one of the most critical elements in the specification and detail design of any suspended-ceiling system. This must take into account the frequency of access required; the extent of services installed in the ceiling panels;
how easily the panels can be removed/reinstalled; and how manageable they are.
Excessively long panels may require two men, ladders and sealed-off areas. Many manufacturers describe their products as demountable. In theory this is true but it is unlikely the workmen will either look at the O&M manual, or have the correct tool.
Combination of failings The combination of these failings is that a screwdriver is used to remove the tile, which damages it and, because of the difficulty that ensues in either removal or replacement, black greasy handprints are left.
Regardless of the design of the ceiling or the design of the combination of ceiling and services, all will fail miserably if the operative fails to display a duty of care, which is down to corporate mentality and the strength of the line management.
The demands of organisations to increase internal communication, and at the same time maximise the use of available office space, have resulted in a change to working practices through hot-desking and more flexible open-plan arrangements.
It is now common practice for managers and department heads to share the general open-plan environment, with little or no difference between a manager's workspace and the space of the rest of the staff. There is, however, a demand for plenty of meeting rooms. Sizes are typically for groups of four to five people or 10-12 people, with additional larger conference rooms as required.
The use of fully glazed, demountable systems, such as Optima, provide good acoustic control without creating a visual barrier to the office space. Where cellular offices are a client requirement, the use of fully glazed sliding doors allows doors to be left open without restricting the internal space. This leaves more room for furniture as well as creating a room that feels more accessible and less inhibiting.
Peter Rowell is an associate with Watkins Gray International