A survey is a type of study or data collection effort within a larger study, a questionnaire is a data collection instrument.
Many surveys use questionnaires that are filled in by the participants, but surveys can use other data collection instruments. While survey usually carries the connotation of individuals being the unit of data collection, the units could be organizations or even artifacts, such as buildings in a city, in which case data would be collected on a form by an observer, possibly using instruments (such as a device that uses infrared for measuring distance) or, in the example, asking the people who worked on the construction or live in the building.
