The Piccadilly Line (Heathrow T5 Extension) Order 2002

7.  The specified works shall, when commenced, be carried out—

(a) with all reasonable dispatch in accordance with approved plans;

(b) under the competent supervision (if given) and to the reasonable satisfaction of the engineer; and

(c) in such manner as to cause—

(i) as little damage to designated property as may be; and

(ii) as little interference as may be with the conduct of traffic on any railway of the Company and the use by passengers of designated property;

and, if any damage to designated property or any such interference shall be caused by the carrying out of the specified works, the undertaker shall, notwithstanding any such approval as aforesaid, make good such damage and shall on demand pay to the Company all reasonable expenses to which they may be put and compensation for any loss which they may sustain by reason of any such damage or interference; but nothing in this paragraph shall impose any liability on the undertaker with respect to any damage, costs, expenses or loss which is attributable to the act, neglect or default of the Company or their servants, contractors or agents.