Regularly and diligently means going about the work so as to achieve the contractual obligations: West Faulkner Associates v Newham requires the contractor to organise its work, to manage and resource its labour force properly, to bring suitable materials to site and to use competent tradesmen, so that the work meets the contract as to standard, time, sequence and quality

To go about the work so as to achieve the contractual obligations. West Faulkner Associates v The London Borough of Newham held that regularly and diligently are read together and require the contractor to plan its work, to direct and manage its workforce, to furnish materials that are sufficient and proper, and to put competent tradesmen on site, so that the work is completed to an acceptable standard and satisfies the contract as to time, sequence and quality. The contractor must proceed continuously, industriously and efficiently, with appropriate resources, so as to progress the works steadily towards completion. The test matters because most standard forms let the employer determine the contractor's employment for a failure to proceed regularly and diligently, and under the JCT forms that route depends on the certifier serving a valid default notice. In West Faulkner the architects' failure to serve the notice left the council unable to determine and liable for the losses that followed.