A definition of 'Excluded Works' with conditional and future language ('if required to be carried out, will constitute a variation') will ordinarily be construed as directed to works not presently required under the contract, not works already obligatory at execution.
The full text is available to signed-in members, including the 19 later cases that cite this judgment.
1 of the 19 citing cases carry a classified treatment. How each court treated it is available to signed-in members.