Creating an ENERGY MODEL of a building as part of the planning process is becoming the norm.
This means hiring a certified Energy Advisor and using programs like:
TESTING of a building will be done with a BLOWER DOOR SYSTEM and through validation inspections during the construction process - making sure that all of the layers are going in where and when they should, and ensuring the target airtightness.
COMMISSIONING of a building is done post-occupancy to ensure that all of the systems are working correctly and that the building meets the modelled airtightness.