Containerised buildings are fully functional and fitted-out datacentres that can be deployed relatively easily and quickly to meet client demand. This can be for Disaster Recovery (DR) or as a temporary measure to provide additional computing power. Containerised buildings can also be used for generators and uninterruptible power supplies. The benefit is that the building itself can be housed close to the main facility or in remote areas and does not require a long build program. Some Mega-sized datacentre operators use a modular approach for datacentre expansion and use custom-made containers and fabricated metal buildings.