Dear [Name of tenant],
Re: [Property address]
An appointment has been made for a contractor, [insert name or company], to visit you to carry out the following essential work: [list works needed to be done].
The work will be carried out on [insert date] at [insert time], and in this instance the contractor requires you to be present at the property.
Please could you contact me to confirm that the above time is convenient, or to make alternative arrangements.
Thank you for your understanding.