Construction Task Force
calls for reduced costs
and construction times

Measures to address these shortfalls were unveiled by Sir John Egan of BAA in August. Sir John’s own company remains at the leading-edge of construction and is driving improvement in building performance.

BAA’s recent £7m ‘First Point’ office development near Gatwick Airport exploits a variety of innovative techniques which have reduced construction costs and will bring significant benefits to BAA Lynton as the property developer as well as to tenants.

The measures include installation of the Hiross Flexible Space system of underfloor air-conditioning which has been fitted throughout the development.

‘First Point’ is a state-of-the-art four-storey office development offering almost 6,000 sq. ms. of lettable office space. It has attractive glass and curtain wall facades and the entire project was completed in under 40 weeks, a speed of construction which exceeds the most stringent guide-lines in the Rethinking Construction report. The client calculates that the underfloor air-conditioning system reduced the construction term by 12 weeks. BAA tenants will also benefit from modern building management technology and distinctive solar shading on the structure’s front elevation.

The Hiross system uses the underfloor void as a supply and return air plenum, the air being drawn up into the occupied space via floor-recessed fantiles with individual remote control, meaning maximum comfort and control for individual personnel.

Air quality, including temperature comfort, remains one of the most pressing ergonomic issues facing facility managers. The only effective solution is to let employees have economical control over the temperature in their immediate work areas, and the use of a raised access floor air-conditioning system is becoming a popular approach. The system can address variations in ambient temperature according to the amount of computer usage in various areas of a building and it also allows individuals to vary working temperatures to suit respective metabolisms and the clothing they wear.

In line with calls in the Construction Task Force’s report for improved efficiency in terms of energy consumption and building dimensions, under-floor air-conditioning can dramatically reduce floor to ceiling heights by exploiting underfloor voids and removing the need for the ceiling void ventilation zone associated with conventional air-conditioning. Height savings are often between 12 and 15% and doing away with false ceilings avoids the acoustic attenuation problems associated with partitions. Reduction in energy usage is estimated at approx. 3%.

The Hiross installation at the BAA ‘First Point’ building underlines the height savings: Alistair Taylor, Associate Director of BAA Lynton, comments: "Overall building height was important on this project and by making use of the floor voids as an air plenum, the Hiross system allowed us to reduce storey heights by half a metre yielding a total height reduction of 2 ms. when compared with similar projects".

The Construction Task Force report outlines measures for reducing construction costs by 10%. The height savings with underfloor air-conditioning have obvious spin-offs in reducing construction costs since structural elements such as lift shafts, glazing etc. are also reduced in dimensions. At a recent installation at the ‘H6’ building in Hong Kong, use of the Hiross system saved 30ms on a 73 storey development. The system requires only 300mm of floor void and the materials and energy savings are immense.

Use of the Hiross system at Gatwick also reduced fitting out times, another issue highlighted in the Rethinking Construction report. Since the underfloor air-conditioning solution does away with virtually all horizontal ducting and pipework, it reduced the fit-out time at Gatwick by several weeks.

Another significant advantage of underfloor air-conditioning is the ability to claim capital allowances of 25 per cent per year on the U.K. mainland and 100 per cent in Northern Ireland. Most businesses think of capital allowances as relating to machinery and traditional items of plant. However, use of floor voids as an air plenum changes the status of underfloor air-conditioning from ‘fixture’ to ‘plant and equipment’. In addition, anything that is placed on the floor such as air-conditioning-fantiles and demountable partitions also qualify for capital allowances. In a recent AET installation at Millbank, the capital allowances were £8m while total services only cost £5.5m.

Prominent in the Construction Task Force’s report is a call for more ‘intelligent’ construction. A common definition of an ‘intelligent’ building is one which can accommodate change. Reconfiguration to suit changing office layouts will be easily accomplished at ‘First Point’ as the floor-recessed air supply units are completely interchangeable with floor panels. This was an important concern for BAA Lynton who envisage multiple tenancies from various airport related companies.

The flexibility of the Hiross system makes significant impact on whole-life costs since staff can be relocated within a building with a minimum of disruption. Panasonic have quoted savings in the cost of change of $150 per m2 per annum at their Paris office compared with conventional ceiling based systems. Digital have reported a reduction in facilities related operating costs in the order of 30% based on observations at their Nice offices. These savings equate to the cost of the rent in many buildings and can offer a payback on total construction cost in 7-10 years.

Deputy Prime Minister John Prescott’s response to the Rethinking Construction report was suitably up-beat. "It pulls no punches with respect to the industry’s scope for improvement. Construction must learn to be more customer focused ... and look from top to bottom at its skills, management training, project management and supervisory skills on site". Innovative use of flexible office solutions will go a long way to achieving these goals.