Lighter and brighter

From the outside it looks totally new – but hidden behind the seven metre high façade are ten different construction phases carried out over more than two decades. Here we are talking about the extended Intratuin garden centre in Halsteren in the Netherlands. Intratuin partner Piet Withagen built his first commercial glasshouse in the Venlo style in 1976. The sales complex has in the meantime grown to include 16 broad aisles. It was time to design the concept anew. Withagen commissioned Thermoflor with the renovation and extension work, as with the nine preceding projects. The Netherlands greenhouse builder replaced the original walls, some of which were 20 years old, with insulating glass, wood elements and sandwich sheeting, while polycarbonate sheets were used for the roofing. “I want to have as much light as possible in the garden centre,” was the condition laid down by proprietor Piet Withagen. “Light is inspiring, light brings a smile.” And so 32 mm polycarbonate sheeting was used for the first time in the entrance area and in the house-plant section. Developed two years ago, this material halves the loss of energy by comparison with 16 mm sheeting. “The amortisation period is less than three years;” declares Ben Boon, sales manager at Thermoflor. And in summer it also provides an insulating effect against the heat. Consistent as he is, the owner also went for a relatively new concept in terms of shade for his glass palace. This consists of sails which are rolled out over, not under the roof. They are controlled by an automatic air-conditioning system and achieve a cooling effect of between six and eight degrees. The modernisation project went ahead in three phases, without any interruption of the actual sales side, up until the reopening in early April 2011. What is more, Thermoflor added a further 5 700 m² to the existing floorspace, which was already huge. Consequently the garden centre in Halsteren now has an overall sales area in excess of 17 000 m². The heated greenhouse accounts for 8 500 m² of this total and the coldhouse for 4 800 m², while the outdoor yard comes to 4 000 m². Steel beams, some arched, stretch over 28 metres in places in the central entrance building, which now has an upper floor with a net floor area of 1 500 m² for offices and social purposes. In the words of Ben Boon, a “green wall” has been built before the entrance façade in order to give the total ensemble a homogeneous appearance despite the different architectural…