Extensions of time

Published November 2014
Effective from 10 February 2015
Reissued July 2024

Delays occur on most construction projects, and always have done. At some point during a project, particular parts of the works, or the works as a whole, will not progress as quickly as planned, with the risk that the contractual completion date will not be met.

This practice information covers:
- costs of delay
- background to extension of time clauses
- delay assessments using BIM and
- strengths and weaknesses of delay analysis methods.

This document was reissued in July 2024 as RICS practice information. It had previously been published in November 2014 as an RICS guidance note. No material changes have been made to the document.

This is part of RICS' Black Book, which is a collection of technical practice documents that covers all processes throughout the construction project life cycle. The documents are essential development tools for junior professionals working through their APC and useful guides to best practice for more experienced professionals.

A project is currently underway to review and update the Black Book content with the aim of producing a comprehensive new edition. Expected to publish in 2025, the new Black Book will comprise an overarching global professional standard, accompanied by practical guidance material.