Notice to defer commencement of works
If the employer fails to afford possession of the site on the agreed date (or within a reasonable time), the contract may expressly provide for the consequences of such failure. For example, clause 2.5 of the JCT 2005 Standard Form of Building Contract (if stated to apply), permits the employer to defer giving possession of the site for a period not exceeding 6 weeks calculated from the relevant 'Date of Possession' provided for in the contract.
This is a template for a notice to defer commencement of works.