Fourth Memorandum on Spatial Planning Extra: that's the literal translation of the Dutch acronym “Vinex”. The memorandum contains all the rules about building houses in the Netherlands between 1995 and 2005. Vinex is often associated with new construction, but some Vinex districts are 27 years old already! 'New' new construction has been covered by the Planning Note since 2004. In Leiden and the surrounding area, there are three actual Vinex districts: Roomburg in Leiden, Leyhof in Leiderdorp, and Broek and Simontjespolder in Oegstgeest.