The property has been owned by The National Trust since 1956, the striking central Rotunda of Ickworth House dominates the skyline forming the centre piece of this historic Grade 1 Listed building which nestles in the 1,800 acres of gardens and wooded parkland. But, for the first time in 200 years the West Wing of Ickworth House is going to be put to use as The National Trust are investing around £4million to create new visitor facilities and a conferencing, banqueting and events venue (accommodating 220) over three storeys within the wing’s historic shell.

Members of the public and The National Trust have been able to visit the Rotunda and grounds for many years and The East Wing, which is privately managed, was recently converted to a hotel. The West Wing, however, has largely been empty since it was built 200 years ago. When Haymills Contractors were employed to carry out the building refurbishment they were faced with an empty shell, and the many challenges of adapting and refurbishing a listed building so it meets modern regulations, whilst retaining the building’s unique architectural features.

From a building services perspective, the challenges were even more acute. The whole use of the West Wing would rely heavily on modern technology to provide the facilities that are necessary to run an effective corporate event. However, working with a Grade 1 Listed Building fabric presented the team with an onerous challenge. Minimum intervention was essential; any structural or services interaction with the existing fabric had to be dealt with sensitively and in a manner which in theory could be reversed at a future date. Chasing out for conduit etc was strictly a non-starter!

Buro Happold Consulting Engineers, along with Hopkins Architects Ltd, were appointed by the National Trust as long ago as 1994, when the original proposals to convert the West Wing were first raised. They were able to bring extensive experience in engineering services in cultural facilities including visitor centres and listed buildings. Over the following years, several schemes of varying scope and cost were assessed before the current one was agreed. Bower Fuller, an East Anglian building services contractor based in Ipswich, was awarded the £940,000 contract to install all the M&E services including, the heating, hot and cold water, lighting, power and fire protection systems.

In the current scheme, the West Wing is entered on the ground floor, through reception. This level also contains a shop, restaurant and serving kitchen, with the stairs and lift going to the lower ground and first floors. The first floor accommodates the seven metre high, 340 square metres conferencing, banqueting and events space called The Gallery, complete with a raised balcony giving stunning views over the gardens and park, and a servery for the kitchen below. At the other end of the first floor is The Court, complete with its Edwardian glass roof. On the lower ground floor there is the main kitchen, The Engine Room (for learning activities and group catering use) and public toilet and staff facilities.

As the existing 200 year old structure was just a building shell, the new floors were constructed from the top down, and in distinct stages, due to the tight access. Firstly, the support beams that would hold the first floor were lifted into place, and then 110mm thick pre-fabricated concrete soffit panels, which would form the ceiling of the ground floor, were installed. At this stage Bower Fuller fitted and wired the ground floor lights, which were recessed into the pre-cast soffit panels. Battens were then laid onto plywood decking on top of the first floor support beams, then the under floor heating pipe work was installed over Jablite insulation and metal plates (to increase heat distribution and output) running between the battens. This pipework was co-ordinated with the numerous flush floor boxes providing the power and the data points needed for The Gallery. The oak floor was then laid on top. The ground floor was built last, and it was not until this stage that Bower Fuller could put in the main M&E services distribution network from the new plantroom in the lower ground floor ceiling void.

The design of the heating for the new building was an unusually difficult challenge. Although the building possesses a very high thermal inertia, an attribute which is essential for maintaining environmental stability and conservation of artefacts in historic buildings, uncertainties around the material properties and consistency made thermal modelling a difficult process. Added to this was the fact that the roof consisted of a slate-clad timber-lined construction, possessing relatively poor insulation and air tightness properties. The thermal loads therefore had to make allowance for low insulation and potentially high infiltration rates.

The heating system supplying the West Wing needed to be designed so that it was as discreet as possible. The solution was to install a mixture of under floor heating, trench heaters and radiators, serviced by three Broag oil-fired boilers, situated in a dedicated plant room that has been built adjoining the West Wing. The boilers provide a total output capacity of 750kw and not only supply the West Wing, but also supply the central Rotunda, via a dedicated constant speed pumped circuit, that replaced a temporary boiler plant that had been installed by Bower Fuller under a previous contract. All the heating is controlled centrally by a Building Management System, which enables the building to achieve a constant temperature and brings the trench heaters, which are mainly located in the window bays, into operation when required.

The under floor heating is controlled using radio signals being received by aerials in the roof, connected to the BMS system.

Buro Happold was faced with the logistical problem of placing the M&E equipment and distributing the services around the building. To maximise the available space within the existing shell, a plant room has therefore been built onto the side of the West Wing.

For planning reasons, the new plant room has been partially built into the ground, with a curved turfed roof so that it blends in with its surroundings, with the flues terminating in a monodraught terminal. As well as housing the boilers, the plantroom also contains an oil-fired hot water generator with a capacity of 350 litres, water softener, three kitchen extract fans, a pressurisation unit and expansion vessel, a low voltage cubicle and mechanical services control panel. A risk analysis of Health and Safety considerations prevented the use of the originally preferred choice of LPG plant in the sunken plant room.

A large overall constraint to this project, both from a design and installation perspective, was that existing openings could not be enlarged and the fabric of the building had to be maintained. One deviation from this was the cutting of a 1.3m×2.4m hole into the existing external wall at low level within the ‘vaults’ area on the lower ground floor. This hole enabled Bower Fuller to link the various M&E services from the adjoining plantroom to the West Wing. Careful co-ordination was required to install 16 service pipes, three ducts and three sets of electrical containment through the opening and beyond, without blocking each other or the access through the adjacent corridor.

In an effective utilisation of space, the existing narrow and low vaults, situated to the rear of the West Wing on the lower ground floor, were also used to house the 8,000 litre cold water storage tank and booster set. To achieve the water storage capacity needed, a bespoke unit was installed by Bower Fuller, measuring one metre high by one metre wide and eight metres long. A three-pump Aquamatic cold water booster gives the water system an operating pressure of four bar.

Lighting of the West Wing has also presented a few challenges and Bower Fuller has installed a system sensitive to the environment. To minimise light pollution, careful consideration has been given to the external lighting. Directional column down lighters have been installed in the car park and the footpath that links it to the building has had 36 buried directional LED lights installed to indicate the route of the path. In The Gallery and The Court, architectural lighting track has been used. Fluorescent modules hidden within the top section of the track provides indirect uplighting to enhance the original roof. In the Events Hall, unusually, the lighting track is not suspended from the wooden roof structure but laid onto the original wooden beams secured by bespoke brackets. Due to the age of the building, these beams are not spaced at regular intervals, so the lighting track had to be ‘made to measure’ to allow it to be supported properly.

Ventilation, especially to the kitchen, food preparation and servery areas, has been duly considered. Air handling units have been fitted vertically in the service riser. The riser itself is used as a fresh air duct, drawing fresh air from outside. Each of the kitchen areas has also got its own dedicated extract system. The kitchen extract equipment is located in the plant room, and each system is fitted with an odour neutraliser and electrostatic precipitator, which cleans the airstream of grease and smoke particles.

As mentioned previously, due to the space constraints, all opportunities to run services out of sight have been utilised. One very unusual location for the heating pipe work was within a vertical shaft that linked a bat enclosure, adjacent to the gallery on the first floor, with a ground floor window where a slot was placed for the bats to enter and exit. The Bower Fuller engineers had to ensure their timing was just right to avoid any nasty collisions with these low flying mammals!

Despite the challenges along the way, the West Wing of Ickworth House is on schedule to be completed in November and the impressive facilities will undoubtedly show it is possible to create a naturally ventilated energy efficient building, whilst retaining the architectural integrity of an historic landmark.

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