Sets out the design and construction of pressure test rigs for use in studying leakage rates of windows and doorways in the Arts building of Sheffield University. Tests 7 doors (including fire doors) and selected windows, categorized according to deterioration of sealants. Finds that window leakage is far in excess of the suggested leakage from the CIBS guide (results of infiltration coefficients range from 0.911-6.097). Shows that 56% of the airflow across a doorway is due to the gap between the door bottom and the floor, and that weatherstripping the door reduces the flow by approx. 50%. Finds that firedoors are 50% tighter than office doors.