Sources of information
| Sources with basically quantitative information | Sources with basically qualitative information |
| Cross sectional prevalence studies done by the local OSH | Minutes, notes, appeals and proclamations from meetings held by the personnel |
| Construction drawings | Minutes from municipal political boards concerned with planning, construction and environment |
| Investigation reports regarding the office building and its physical environment, performed by the proprietor and his consultants, the local OSH and the municipal Technical Office | Messages and pronouncements from the Labour Inspectorate |
| Letters exchanged between employer, employees and proprietor | |
| Articles from local news media | |
| Interviews with a selection of persons who worked in the building, or had other relations to it |