Dalby Visitor Centre, Lower Dalby village, North Yorkshire

Introduction

Dalby Forest is managed by the Forestry Commission and is the largest forest in Yorkshire. It receives around 300,000 visits per year making it a key visitor attraction in Ryedale and the North York Moors National Park. The facilities for visitors at Dalby have developed organically over the last 40 years; initially, in the 1960s, a ‘forest drive' was opened to create a through route for visitors on their way to the east coast, subsequently a ‘museum' was opened at Dalby village, followed by the creation of a new lake, way-marked trails, wcs and picnic areas. This has been in addition to the main economic use of the forest as a timber resource.

In the last few years the emphasis has changed; visitor revenues now exceed those from timber and the forest is pivotal to local tourism. The new visitor centre replaces facilities - community room, shop, restaurant and exhibition areas - formerly housed in buildings which have now been redeveloped to provide a cycle centre; the centre also aims to improve and develop the forest as a regional centre of excellence for sustainable economic activity.

 

Building description

The general aims of the design were to minimise the impact on the valley and focus upon sustainability both during construction and operation. At the heart of the plan is a double height foyer which links all facilities. On one side is a two storey element housing community facilities, a restaurant and services, while on the other side is a single storey retail and exhibition building. The two elements are angled to form a welcoming space into which visitors from the main car park are focused.

One of the main considerations of the design was to minimise the impact on the valley topography. The existing sloping site was modified to provide a level area on which to site the building. This intervention was kept to a minimum by using a 'cut and fill' technique, which enabled minimal movement of soil.

The building is designed to sit lightly in the existing landscape and its orientation along the natural sight lines of the valley minimise its visual and physical impact.

Provision of a rear service yard for deliveries, bins and rangers vehicles was created by forming a 'hollow' in the existing slope by using planted reinforced banking. The building is screened from the high level, passing road by planting, chosen to reflect the natural planting found elsewhere in the valley and to provide new natural habitats for birds, butterflies and other wildlife that the building footprint removes.

 

Accessibility

The centre is designed to be accessible to everybody, including disabled people. The main public entrance  - the ‘arrival courtyard' - faces the car park and its access to the main entrance foyer is all on one level and suitable for wheelchair use. All facilities - restaurant, shop, public wcs and disabled wcs, community room and exhibition area - are accessible directly from the entrance foyer. The first floor balcony, also all on one level, can be reached via the main entrance foyer by means of a lift or a staircase. By controlling access from the foyer space, all facilities can be operated separately when desired for evening events or during quiet periods.

 

Materials and method of construction

The latest building techniques were used in construction to enhance quality, sustainability and speed. The building sits on steel screw pile foundations, which reduce the amount of site excavation work needed and can be easily removed and recycled in the long term if required. The main structure consists of a pre-made glulam timber frame and prefabricated wall, floor and roof units, all of which are made from structural insulated panels (SIP). The units were delivered to site ready for erection.

This semi-prefabricated solution reduced time on site, site traffic and overall disruption. The building is clad externally in 100 x 25mm larch boards grown and milled from the surrounding forests and fixed to 50 x 25mm larch battens. Some ceilings and walls internally are also clad with larch boards. The extensive use of timber enables the embodied energy and energy expended during construction to be dramatically reduced over that of a typical concrete and masonry building. Timber is also a truly renewable material and by sourcing a considerable amount from the local area this not only reduced the building's embodied energy but also enabled the support of local businesses.

 

Energy efficiency

In the experience of the architect, the approach of 'bolting on' expensive sustainable systems to fix design issues is not truly sustainable or a good use of funds. The key is to make sure the building is naturally energy efficient in the first place by considering such issues as location, materials, insulation, window sizes and orientation.

The building has been designed to maximize natural ventilation and natural lighting to make it as energy efficient as possible. Renewable technologies have also been incorporated to help reduce its impact on local resources.

The naturally ventilated foyer allows all connected spaces to be naturally ventilated by the use of automatic high level opening windows. The height of the foyer space uses the 'stack effect' (hot air naturally rising) to pull cool air in through the lower windows during hot summer days.

The building is also constructed to be thermally efficient. The pre-insulated timber panels come in widths that allow for higher levels of insulation than conventional masonry construction, providing the building with a 'super insulated' external envelope. This extra insulation reduces heat loss and consequent energy consumption.

The installation of a photovoltaic 'thin film' array in the atrium, as well as a micro wind turbine on the roof, provide renewable energy supplies for the building's electricity requirements. A biomass boiler, run on the waste wood chip produced by a local sawmill from wood supplied by The Forestry Commission and private sector, heats the building as part of a carbon neutral process.

Rainwater harvesting is installed to dramatically reduce the volume of water taken from the village well supply. The roof to the atrium and the support building is covered with an inert single ply roof membrane off which rainwater can be collected. This water is used to flush the large number of public conveniences on site.

The sustainability commitment has been applied to the interior fit-out; the reception desk is made from recycled mobile phones, Wellington boots and yoghurt pots; the wc cubicle doors are made from recycled plastic.

Dalby Forest visitor centre won the prime minister's Better Public Building Award in 2007.

Completion Date:

2007

Year Published:

September 2008

Building Type:

Visitor centre

Location:

Lower Dalby Village, North Yorkshire

Country:

England

Client:

The Forestry Commission

Architect:

White Design Associates

Structural Engineer:

Halcrow

Main Contractor:

Millers Construction

Project Manager:

Turner and Townsend

Timber Supplier:

The Forestry Commission Pre-fabrication SIPs supplier: Builditgreen

Timber Element(s):

Glulam timber frame Pre-fabricated walls, floor and roofs cladding

Timber Specie(s):

Larch and glulam

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