The kickoff of Open Monumentendagen, September 10 and 11, was held at the circulair paviljoen ‘The Field’, with the presentation of the first program booklet. Sustainable lasts the longest, Alderman Van Delft paraphrased this year’s theme. In Leiden and Leiderdorp, 34 properties can be visited, all with something special about wind and water energy; insulation and ventilation; heat and light or recycling of discarded materials.
‘The Field’, Stationsplein 25, next to Leiden CS Station and the tunnel towards Plesmanlaan is the epitome of materials reuse. The steel beams supporting the roof were left over from the demolition of the old Gorlaeus Laboratory, which was resurrected a few hundred meters away and permanently demolished. The table in the center of the room, previously stood in the public area of City Hall as a reading table. All the wood – and construction work is reclaimed material from demolition properties. The roof is overgrown with sedum grass that retains coolness in the interior space.
After a major rebuilding and renovation, which took about 1 ½ years, Stadshuis is ready, and this weekend offers Leiden residents the opportunity to also visit the non-public areas in a guided tour. City council members are guides and perhaps Mayor Henri Lenferink will be your tour guide. In addition to the transformation of the street-level public space and the renovated Council Chamber and Civic Hall, you will be made wiser about sustainability here. Much has been improved on the building’s insulation with the latest technology. For example, the canal water is a heat store. Carefully worded, the description states that perhaps 70% less gas is needed to heat City Hall.
Rapenburg 49, once a 15th-century monastery, is completely off gas. An air heat pump located on the roof provides heat. In connection with all the stories about noise nuisance, you might want to listen here in addition to looking.
A look inside the socio-cultural institution ‘The Vrijplaats’ Middelstegracht 36, you fall from one surprise into another. The former boiler house and power plant of the Tieleman and Dros vegetable and canning factory now houses the giveaway store, eatery and a concert hall. All built by volunteers. On Open Monumentendagen, the history of Stichting Industrieel Erfgoed (STIEL) is on display here. Almost all the walls in the building have a layer of 10 to 12 inches of rock wool and an air cavity. The energy efficiency of the property has been increased with two sealed wells, each 100 meters deep, to which a water-fed heat pump is connected for underfloor heating. For deaf people, there is a route through Hortus Botanicus and the Academy Building with a sign language interpreter.
More information can be found on the website of Open Monumentendagen Leiden