Poised above a man-made lake in Hampshire, the Fishing Hut is a small but beautifully crafted timber building; it has an elegant simplicity achieved by the integration of design, structure and sustainability.

The lake is fed by a typical Hampshire chalk stream – shallow, fast-flowing and exceptionally unpolluted – making it the perfect habitat for migrating eels, brown trout and other fresh water fish and providing some of the best fly-fishing in the UK. The hut was designed for use during the trout-fishing season as a shelter for anglers, as a place to store boats and fishing tackle, but also as a base in the landscape for the owner and his family. When in use it had to be as open as possible to make the most of the surrounding rural views.

At the same time it had to be possible to secure and close up the building when not in use. To resolve these contradictory qualities, the walls comprise a series of oak sliding glazed screens with oak shutters on the outside. The shutters are hydraulically operated to lift upwards; when they are open they transform the building into an open platform with views over the lake and when they are closed down they create a secure enclosure.

Timber was the natural choice of material for the structure, cladding and principal elements of the hut and its barn-like form echoes the local vernacular of timber agricultural buildings. The exposed timber structure, shutters and cladding are made of oak, chosen for its durability and characteristic colour and grain. It is untreated and will weather to match the silver-grey colour of the roof covering and the steel supports which emerge from the water.

The building rests on pad foundations which were set on the lake bed and consist of precast concrete drainage rings filled with concrete. Rising from them, nine galvanized steel goalpost frames support the timber floor structure and the timber frame superstructure, a series of oak glulam columns and beams which form ten bays at 1.8 metre centres. The glulam columns support simple oak glulam trusses and the beams project at the eaves.

The plan is accommodated within the ten 1.8 metre structural bays. A pair of bays at the entrance end of the hut form an open deck which bridges across the lake bank. Another pair of bays at the far end of the hut project over the lake; both pairs of bays are partly covered by the overhanging pitched roof. The six central bays comprise a weather-tight internal space of four bays and a semi-enclosed storage area enclosed by cladding, glazed screens and shutters which extend to the eaves. The first bay of the internal space contains an entrance lobby, WC, kitchenette and dining area. The other three bays form an open plan area enclosed by sliding glazed screens. The storage area beyond contains a loft for boat storage, an external shower and a covered mooring with a removable floor and water gate.

The external walls of sliding glazed screens and slatted oak shutters are fixed between the oak glulam columns and beams. The shutters pivot upwards from the eaves to lie parallel with the projecting oak beams, transforming the interior to an outside space and acting as large horizontal brise-soleils. Both architect and structural engineer considered that the use of flitch plates and visible bolts or pellets to connect the oak glulam members would be inappropriate in such a finely crafted building.

Instead the main structural connections are by direct bearing; the top of each column is notched to slot into a rebate in the beam above. Each connection is fixed diagonally by high tensile screws and concealed by being fixed from above. The horizontal roof truss members prevent roof spread and avoid the need for a ridge beam. The roof is formed of insulated softwood rafters, clad internally with 15mm thick finger-jointed oak boards and externally with profiled aluminium sheet on larch battens.

To fabricate the structure, the architect approached Inwood Developments of Lewes, one of the few UK companies which produce oak and hardwood glue-laminated components to order. Inwood developed the timber process and fabrication details with the architect and became general contractor, sub-contractor and specialist supplier, manufacturing and prefabricating the majority of the building elements apart from electric installation, plumbing and steelwork.

The beams and columns were glue-laminated in the Inwood factory from 22mm kiln-dried and graded PEFC-certified European oak from France. The glulam components in the kitchen area were of FSC certified Douglas fir sourced from southern England. The glazed screens are of tenoned and jointed oak; the shutters are of vertical oak boards spaced apart on an oak frame with connections and actuators of stainless steel to avoid bi-metallic corrosion. All were prefabricated as individual items in the Inwood factory before being installed on site and sealed with a UV-protection oil.