Brabazon was also going to be the first modern aircraft to be designed with pressurisation in mind. This system would allow the aircraft to fly at a greater altitude. This would make the engines more fuel-efficient. The cabin being pressurised would maintain a much lower altitude for passenger comfort.

To accompany this the aircraft would have temperature-controlled air-conditioning, and set the pattern for all future passenger aircraft. The system would aim for a cabin altitude no higher than 8000 feet and a cabin temperature between 18C - 24C. This was deemed to be the most comfortable.

To achieve this, new equipment was needed, new controls to monitor its performance and new skills for flight engineers to learn. The aircraft was to be 100% powered flying controls, therefore needing hydraulic servos to operate control surfaces. Hydraulic systems had to convert right amount of pilot input whilst feeding back enough 'feel' to enable the pilot to fly competently.