The Piccadilly Line (Heathrow T5 Extension) Order 2002

Power to deviate

5.  In constructing or maintaining the scheduled works, the Company may—

(a) deviate laterally from the lines or situations shown on the deposited plans within the limits of deviation for that work shown on that plan, and

(b) deviate vertically from the levels shown on the deposited sections—

(i) to any extent not exceeding 6 metres upwards; or

(ii) to any extent downwards as may be necessary or convenient.