The search for a suitable location for experiments, also in the military sense, was after some time married to the decision to construct a new building for the Military Weather forecasting Service, to be situated on the Plain of Waalsdorp in the dunes near the present day TNO-FEL building.
Here Van Soest and an "Instrumentmaker" (mechanical engineer) as assistant started work formally on
December 1st 1927.
These two people were provided with 3 rooms totaling to 100 sq. meters floor space. The date
mentioned has since then yearly been celebrated
as the day of the foundation of the laboratory. However, in order not
to arouse unnecessary suspicions
in those prewar years the premises received
the name "Measurements Building" rather than "Laboratory".
This name was in use until the German invasion in 1940.
In this period the Measurements Building was active in different areas. This concerned the subjects Air Acoustics (listening equipment to localize air planes) and transmission of shaft positions (fire control), Radio Communication (transportable telephony equipment), telemetry (weather balloons) and "electric listening" (later called Radar), results of which were all taken into industrial production.
A physics application such as using infra-red light for the defence of rivers was in an advanced stage of development. The items IFF, landmine detection and Underwater Acoustics were still in the experimental stage. The number of employees grew in the prewar years to 37 in 1940. The workfloor increased to some 400 sq. meters.