late 1960s

1966
J.A.G. van der Steur suddenly died. He had updated his masterplan to a version that could still be used in 1967, but his succession meant changes in the way 'De Uithof' further developed. In the mean time, plans for the buildings for physics and mathematics had been prepared, as well as for the veterinary clinics. All of those were designed by the architectural firm Haskoning.

1967
The board of the university appointed J.A. Kuiper as successor to Van der Steur. M. (Marinus) Ruppert (Dutch only) became curator for all building affairs. Towards the end of the 1960s student numbers expanded rapidly and the developmental plans could not keep pace. Drastic measures were needed and without much planning it was decided that 'Transitorium 2' (now known as the 'Willem C. van Unnikbuilding') would have to be erected. The building was designed by the office of Lucas and Niemeijer and identical to buildings produced in The Hague and in Rijswijk. Without a proper programme and without much hassle concerning permits an office tower could be built in a short time. The construction method was special: jack block, which meant that the top floor was constructed first and joisted upwards by means of hydraulic techniques. Van Unnikbuilding has been the highest building of 'De Uithof' (75 m.) for many years, and developed from an architectural accident into an unplanned landmark. At present the highest building (80 m.) is the new building for National Institute for Public Health (RIVM) and Medicines Evaluation Board (CBG), to be opened in 2022.

1969
From 1967 onwards, the spatial planning of 'De Uithof' became the result of joined effort. Kuiper was unable to produce a new masterplan that could provide enough flexibility and could keep up with the ever-changing growth perspectives of the university. As a result the architects that worked on 'De Uithof' started what became known as the 'architectenoverleg' (the architect's consultation) and formed a planning team without any payment. E.F. Groosman (designer of the Kruytbuilding), J.A. Lucas, D.J. Istha, M.F. Duintjer, G.J. van der Grinten (designer of the Wentbuilding), Sj. Wouda, H.C. Stadlander and J.D. Schoute (both from Haskoning) laid down their ideas in scale models. Their consultations were meant to prevent the occurrence of planological anomalies, but unfortunately not much of their views were kept for future reference. On the basis of the scale model of 1968, maps were drawn in 1969 titled 'schetsontwerp De Uithof'. A huge university campus was perceived including wide, partly three lane roads. Most buildings were meant to be connected at level plus 1 through bridges.