Main areas can be
a) process area
b) auxiliary plant
c) tank area
d) pipe trenches
f) control rooms
g) manned buildings in general (workshop, laboratory, fire station, administration buildings)
h) unmanned buildings (substations, analyser building, warehouse)
j) vehicle loading/offloading areas
k) parking lots
l) temporary office buildings, containers, etc.
Source: Guidelines Regarding the Technical and Operational Regulations, Norway, updated December 2012. Regulatory Guidance
Area or building block on the facility that contains identical or similar functions.
Source: Regulations Relating to Technical and Operational Matters at Onshore Facilities in the Petroleum Activities, etc. (The Technical and Operational Regulations) Norway, April 2010 (amended December 2010). Regulations