Paragraph 10

If any alterations or additions, either permanent or temporary, to designated property shall be reasonably necessary during the construction of the specified works or during a period of 12 months after the completion thereof in consequence of the construction of the specified works, such alterations and additions may be effected by the Company at a reasonable cost after not less than 28 days' notice in writing (save in case of emergency whereupon the engineer shall give such notice as is reasonable in the circumstances) from the date of the submission of plans, programmes and estimates of costs of such alterations and additions having been given to the undertaker, and the undertaker shall pay to the Company on demand the cost thereof as certified by the engineer.