New Worcester Royal Infirmary

Citation

(2001), "New Worcester Royal Infirmary", Facilities, Vol. 19 No. 5/6. https://doi.org/10.1108/f.2001.06919eaf.002

New Worcester Royal Infirmary

New Worcester Royal InfirmaryKeywords: NHS, Structural engineering, Building services, Ventilation, Lighting

These days most hospitals or hospital units are either built on tight urban sites or are extensions of existing buildings. The new acute hospital at Worcester is perhaps more unusual because it is being built on a green field site. At £82 million the hospital is one of a number of large hospitals being constructed throughout the UK under PFI contracts.

Oscar Faber, a services and structural engineer, is both the services and structural engineer of this prestigious project. The company is not new to such large health care projects bringing with it recent experience from building a new hospital at Halifax.

The 452-bed hospital is being built adjacent to the Worcester Royal Infirmary Newton Road site. Oscar Faber started work on the services design in July 1998 to meet a financial close deadline of March 1999 and construction began in May 1999. Although the contractual completion was January 2002, it looks likely that the building may be finished up to three months earlier in October 2001.

The brief was for a new acute hospital to serve Worcestershire, a need that was recognised many years ago. The client is PFI consortium Catalyst Healthcare, which will operate the new hospital for 30 years for Worcestershire Acute Hospitals NHS Trust. The project team includes architect RTKL UK Ltd with Bovis Lend Lease as the design and build contractor.

Building layout

The hospital is designed as a deep-plan building of 38,000 m² and is on three floors, which step up the sloping site. Two ward blocks sit each side of a rectangular central block that is built around a three-storey courtyard, which brings light into the centre of the building. The main thrust of the ventilation strategy was to maximise natural ventilation. This included placing as many rooms as possible on the perimeter of the building. The hospital accommodation includes wards, the largest being a four-bed ward, eight operating theatres – four of which are ultra-clean areas – a pathology laboratory, radiology department with its MRI scanner, accident and emergency department and a 15-bed intensive care unit. Other departments include maternity, paediatrics, coronary care, pharmacy, trauma, orthopaedic, audiology, oncology, oral surgery and dermatology.

Visitors and out-patients will enter the building via a large, south facing, fully glazed entrance foyer, of the type more usually associated with a large office or hotel. Solar control in this air-conditioned space will be via a ceramic fritted coating on the glass itself.

In PFI projects, user involvement tends to occur after "financial close" when the cost of providing the service and building has been agreed. Without careful management, costs could easily escalate in response to users' demands. Yet for any building to work well, the needs of the users are vital to the briefing process. On this project, data sheets for each room were prepared by the design team and a series of user meetings were held with representatives from each department to comment on the drawings.

Servicing strategy

This is a highly-serviced building. The services account for 44 per cent of the total construction cost of the building.

The building will be partly naturally ventilated with some space heating provided by high-level radiant panels. Mechanical ventilation and air-conditioning serves areas which are either not suitable for, or not able to benefit from, the natural ventilation. All the wards are naturally ventilated being on the building perimeter. The air-conditioning is an all air system with a constant volume supply, and heat recovery is via run-around coils. There are 28 air handling units in the roof plant room and these are split across departments and operating hours. The roof plant room also houses two 1.25MW air cooled chillers, plus a smaller chiller dedicated to the MRI scanner.

A boiler house at garden level includes three 2.3MW dual fuel boilers which can run off gas or light-grade oil. Two dual fuel steam generators, also in the boiler house, provide humidification and serve the autoclaves.

Variable volume pumping and variable speed drives on all the fans are being used for energy efficiency.

The intention of the design has been to optimise the combination of naturally ventilated areas and those requiring air-conditioning, such that while no area is overserviced, comfort conditions can be maintained for staff and patients alike.

Public health

There is a full medical gas installation with oxygen, compressed air and nitrous oxide, distributed around the building as required, not only to theatres, but also to other departments and bedheads.

The laboratory water systems to the pathology laboratories and autoclaves are purified through reverse osmosis. This process involves pressuring feedwater and passing it through a semi-permeable synthetic membrane, removing some 98 per cent of the dissolved salts.

One of the difficulties associated with the infrastructure was that the sewers were unable to cope with the peak flow from the new hospital. To overcome this, a 225,000 litre underground tank was installed. Waste is pumped from this at a constant flow rate, thus ensuring a constant flow to the sewers over 24 hours, while coping with the peak demands from the building.

Electrical servicing

The maximum electrical demand is 4MW. Electricity is supplied from the mains to two separate high voltage switchboards each in separate fireproof rooms. A back-up generator also feeds each switchboard. From the switchboards the supply is taken out to each side of the high voltage ring around the hospital. Automatic detection on the ring main enables the system to be reconfigured automatically if the supply to any part of it is interrupted.

Essentially there is a duplicate feed all round the network. The 11kV ring feeds three pairs of transformers all of which have 100 per cent space capacity. Two pairs independently serve the main power and lighting to each half of the hospital, and one pair serves the mechanical switchboards. Duplicate bus bars run from the low voltage switchboard and feed the power distribution throughout the building.

The lighting systems in the hospital range from the specialised theatre lighting, providing illuminance levels up to 50,000 lux, to feature lighting in the enhance foyer. One of the key aims of this building is to create a welcoming environment, more akin to a hotel in certain areas – lighting plays a major part in this. For reasons of energy efficiency, the majority of lighting is fluorescent, although some limited use is made of tungsten lamps in areas where fluorescent will not work, for example the MRI room.

External lighting is important not just for security, but to provide a welcoming atmosphere to patients and visitors. The car park lighting has been designed to achieve an average illuminance of 20 lux. Most of the luminaries either limit or do not produce uplighting and so reduce light pollution. The exceptions are a limited number of floodlights.

For further information contact Bill O'Neill. Tel: +44 (0) 20 8784 5986.