4 Pursuant to the directions of the second respondent, the first respondent filed points of claim. Relevantly, it filed amended points of claim on 8 August 2002 (Appeal Book, volume 1, page 192). These points of claim identified the parties, detailed the documents comprising the building contract and referred to certain express terms of the agreement (par 1 to 5). By par 6 of the amended points of claim the first respondent pleaded that there were terms to be implied in the building contract that first the appellants would not interfere with the progress of the works and second, the first respondent would not be liable to the applicants for any delay caused by any act "of prevention" on the part of the respondents. It is said (by par 7) that the first respondent commenced the works on or about 21 February 2000 and that it brought the works to practical completion on 20 March 2002 (par 8). It is then said that pursuant to the terms of the building contract the first respondent was entitled to extensions of time for completion of the work totalling 335 days (par 9). Particulars of this claim were provided. It was said that pursuant to special condition 1 of the building contract, the first respondent was entitled to an amount of $16,432 by way of compensation for GST (par 10). The first respondent claimed it was entitled to interest on progress claim no 3 as a consequence of the applicants' failure to make payment on time (par 11) and it was said that consequent upon adjustments under the building contract, the sum due on practical completion had increased from the contract sum and allowing for payments made to date, there was a balance of $101,250.08 outstanding (par 12 and 13).