The Dyson Centre for Neonatal Care, Bath
The Dyson Centre for Neonatal Care (NICU) at the Royal United Hospital in Bath cares for more than 500 premature and sick newborn babies each year; it has been designed as a template to show how good, sustainable healthcare design can be achieved, setting a benchmark for good practice, and creating a therapeutic environment to benefit parents, children and staff. It also challenges conventional healthcare construction by using a cross-laminated timber (CLT) structure with exposed internal surfaces. For the architect Feilden Clegg Bradley Studios, this new building was their first venture into the healthcare sector. With no preconceived ideas, the team explored assumptions about what would be appropriate and possible.
The original unit, which it replaced, was cramped, inefficient, dark and lacked privacy, exacerbating the stress of already anxious parents and users. Both architect and client considered it essential to create a new environmentally sustainable building with a quiet environment to help reduce the stress of seeing one’s newborn sick baby in a highly technical setting and to promote holistic healing.
The original unit, now refurbished, provides facilities for staff and parents and is connected to the new building by a link which acts as the main entrance, gives access for emergency vehicles and creates a private sheltered courtyard a ‘break-out’ space for parents and colleagues.
The plan of the new single storey building is organised in a horseshoe arrangement around a centralised staff base where parents can clearly see their babies progress and journey from critical care through to going home; psychologically this was very important for both the parents and the staff. The staff bases/clinical areas at the centre are linked by a continuous corridor to a series of care/treatment rooms at the perimeter; these treatment rooms are arranged in a clockwise direction to reflect the intensity of care –beginning with intensive care, followed by high dependency, then special care, on to the parents’ rooms and finally, recovery.
The use of natural light was especially important to both patients and staff, allowing them to perceive the changing conditions of day and night. Consulting examination rooms and treatment rooms are daylit with clerestory windows along the external walls and generous windows reaching to low level to give an external focus for moments of quiet reflection. Central clinical areas and corridors are lit with continuous overhead rooflights. Daylight is carefully controlled to ensure that babies gain an awareness of day and night as they develop.
The use of timber
Although the unit had to meet stringent technical requirements, it was also essential that the interior should not appear too clinical but should feel warm and calming. In addition it had to be as sustainable and environmentally friendly as possible, minimising embodied energy in construction and use. For these reasons a timber structure was a natural choice and the use of a CLT structure had the additional benefit that internal surfaces of the panels could be exposed, creating a calm and domestic environment within an acute clinical setting.
The cellular nature of the plan allowed both external and internal walls to be of loadbearing CLT panels. The external walls to the north and south elevations have high level clerestory glazing and the 215mm thick CLT walls are designed with a series of upstanding ‘teeth-like’ columns set between the glazing to support the edge of the roof deck.
At the centre of the building the roof rises to accommodate a central high-level walk-through service duct which distributes services throughout the unit and allows for unobtrusive replacement of equipment in the future. The duct is set above the staff bases and flanked by sloping rooflights on each side which light the corridors below. It is constructed of CLT panels which act as deep beams, at one point spanning seven metres over the staff base and offices below. The panels incorporate pre-cut openings for ducts and pipework which lead into the suspended ceilings of the treatment rooms.
External wall panels vary in thickness between 169mm and 215mm. Internal CLT cross walls are 142mm thick, with internal corridor walls 169mm thick to support medical equipment. The roof decks of the treatment rooms comprise CLT panels of constant 198mm thickness which are supported by the walls and which in some areas cantilever over them. The decks support the weight of the sedum roof, the mechanical services and the suspended ceilings.
The CLT panel system was quick and clean to build, avoiding the need for wet trades such as plastering, and construction was relatively quiet, factors which were particularly important in an acute healthcare environment. The CLT panels were pre-cut to size together with all openings, including those for windows and ducts, in the factory in Austria, transported to Bath and erected in only three weeks.
External walls are lined with rigid wool fibre insulation and clad with a rainscreen of Parklex high-pressure laminated timber panels, secured on support rails fixed back to the CLT wall structure.
Finishes and fire rating
Where the CLT wall panels are exposed internally the structural thickness is designed with a sacrificial layer which is assumed to char at 0.76mm/min. The exposed CLT panels are Domestic Visual Grade and their interior surfaces were treated with a three-stage protective coating which maintains the natural feel and colour of the timber, while reducing its tendency to yellow with age and achieving Class O Spread of Flame. The finish was approved by the infection control team at the hospital.
Sustainability in construction and use was central to the design of the new unit and it has achieved a BREEAM rating of ‘Excellent’.
The CLT panels were manufactured by KLH in Austria; their calculations, offsetting transport from Austria to Bath, show the total stored/sequestered carbon in the CLT panels is 79 tonnes. The flat roof is planted with sedum to help attenuate rainwater and to increase biodiversity on the site.
Building Performance Evaluation
A research team was set up to measure the effect of the new building on staff, parents, babies and the environment. Its results show that the new unit is quieter, has more available and controllable light and is more energy efficient. Staff spend more time in clinical rooms and parent and baby interaction has improved.
The building is one of the first examples of the use of CLT in a healthcare environment; it demonstrates that the the material can help to achieve a sustainable agenda, its surfaces can fulfill the requirements for infection control and it can create spaces which are calming and comfortable to users and staff.
2012 RIBA National Award
2012 RIBA South West Regional Award
2012 RICS Award
2012 Building Better Healthcare Awards – Best Inpatient Facility Design
2012 SW Built Environment Project of Year and Award for Innovation
September 2011Building Type:
Healthcare / HospitalLocation:
Royal United Hospital, BathClient:
Royal United Hospital, BathArchitect:
VinciCLT Supply and Erect:
Structure, walls, floors, external cladding, internal doorsTimber Species:
Prepared by Alinea in association with TRADA member Engenuiti, this document presents two detailed exemplar cost models, one each for a CLT and concrete design for a seven-storey private residential building. The scheme has been designed with both a timber and concrete solution in mind at the outset, for ease of...
This Wood Information Sheet (WIS) looks at some of the factors to consider when specifying a desired service life for structural timbers that are to be exposed outdoors but not in contact with the ground.
This WIS addresses general principles of structural design only, giving an overview of the...
A list of British Standards which relate directly to timber, updated bimonthly.