If you are planning a large-scale project involving significant number of telephone extensions, please consult the telephone installation project guidelines. These guidelines are intended for architects, contractors and Estates colleagues who are involved with major build and refurbishment projects. Document Telephone Installation Project Guidelines (133.69 KB / PDF) The guidelines will be re-issued when circumstances require. Please check that you have the most up-to-date version of the guidelines, which will always be available through the above link. This article was published on 2024-10-08