After repackaging, the archive consists of 8 archive boxes and 1 photo box. The photographs are packed separately for reasons of material.The material is divided into six chapters:personaliaeducationactivities as an independent architect 1947-1990stadbouwmeesterschap 1962-1969subjects of researchcommitteeactivities and membershipsvoordoorings and manuscriptscollected documentsUnder category 3 is the project documentation. The term 'project documentation' was chosen instead of 'project files' because there are hardly any drawings in the archive. There is no question of 'files' in the actual sense of the word, it is not a collection of documents belonging to a project but only a collection of documentation material.The files are arranged by sequence number as given on the list of works (see appendix or explanation later in this chapter). These serial numbers appear at the front of the margin. When the dating in the description is uncertain, it is in square brackets [ - ]. At the end of the list of numbered project descriptions are the projects without number (s.n.) and without year (s.a.).Categories 7 and 8 include material that is not clearly project-related. These include: lectures and manuscripts and collected papers. The lectures and manuscripts were given and written by Nielsen, the collected papers were collected by Nielsen.In the works list in the appendix, the projects for which material is in the archive are shown in italics.There was no works list in the Nielsen archive. However, there is a works list from Nielsen's archive in the PSVA file. This list was copied and added to the archival material (request number d56). The projects Nielsen designed as a private architect from 1946 to 1987 are arranged by sequence number. On this list, the sequence numbers of the "executed works" by the Architectural Group 69 Groenhout office are marked. However, some executed works have been forgotten by the firm and have been highlighted by the inventor (request number d56).The sequence numbers also serve as ordering criteria on the works list in the appendix. The order is roughly chronological.