
Doctrine of 'gebundelde deconcentratie' (clustered deconcentration).
Defined the intellectual core of post-war Dutch spatial policy and growth-centre thinking.
The Tweede Nota over de Ruimtelijke Ordening of 1966 made the principle of gebundelde deconcentratie, or clustered deconcentration, the central idea of Dutch urbanisation policy. Confronting the outflow of population from the largest cities and the threat of unchecked suburbanisation, it proposed channelling growth into a hierarchy of selected, mostly existing centres rather than allowing dispersal across the countryside. This was intended to satisfy demand for low-rise housing in green surroundings while protecting open land, notably the Green Heart of the Randstad. The memorandum included an ambitious structural sketch of the Netherlands in the year 2000, organising settlement around a developed concept of hierarchical centres linked by infrastructure.
The Second Memorandum supplied the conceptual core of post-war Dutch spatial planning, with clustered deconcentration framing how the country accommodated population growth for the following decades. It laid the intellectual groundwork for the growth-centre policy of the Third Memorandum and remains a touchstone for the Dutch planning tradition of steering, rather than merely permitting, urban expansion.
Adopted as national doctrine, its principle of clustered deconcentration shaped Dutch growth-centre (groeikern) policy through the 1970s and 1980s.
The forecast of 20 million by 2000 proved a large over-estimate, undermining the scale of dispersed growth it prescribed.