Can I combine two or multiple NCC building classes into one to simplify energy compliance?
The answer is yes. If parts of your building meet the following criteria, you might classify these parts of your building in the same building classification as the major part of your building [NCC 2019 Vol 1.0 Part A6.0 (2)]:
- Both building classes have to be inside the same story; and
- The minor use must not be class 2,3,4 or class 8 (laboratory); and
- The minor use floor area must be less than 10% of the floor area of that story.
Also, rooms with general use like WC and rooms that contain mechanical, electrical or thermal facilities like plant rooms are all classified as the major use of the building. This also includes occupiable outdoor areas (unless another building classification is more suited for it). [NCC 2019 Vol 1.0 Part A6.0 (4)]
Note that NCC expects you to classify each part of the building according to its specific use and purpose, and each classification must comply with its requirements and conditions.