things, the choir practice rooms. The earliest coloured glass windows in the cathedral date from the late 12th century, whilst others are as new as the four Ervin Bossányi windows in the south-east transept (1957). Many have already been conserved and protected by the team of stained glass conservators led by Leonie Seliger. However, much conservation work remains to be done, notably on the Oculus window in the south-east transept – a late 12th-century round window. During the autumn of 2008, a major restoration of the lead roof over the transept was completed at a cost of approximately £500,000. In 2018, the lead roof of the nave was replaced. The extensive restoration of the cathedral that was underway in mid-2018 was part of a 2016–2021 schedule that also includes improved landscaping and accessibility, new visitor facilities and a general external restoration. The so-called Canterbury Journey project was expected to cost nearly £25 million; the funding included a £13.8 million Heritage Lottery grant, £10.9 million from the Canterbury Cathedral Trust and £250,000 from the Friends of the Cathedral. Foundation The Foundation is the authorised staffing establishment of the cathedral, few of whom are clergy. The head of the cathedral is the Dean, currently David Monteith, who is assisted by a chapter of 30 canons, four of whom are residentiary, the others being honorary appointments of senior clergy in the diocese. There are also a number of lay canons who all together form the greater chapter which has the legal responsibility both for the cathedral itself and also for the formal election of an archbishop when there is a vacancy-in-see. By English law and custom, they may only elect the person who has been nominated by the monarch on the advice of the prime minister. The Foundation also includes the choristers, lay clerks, organists, King's Scholars, the Six Preachers and a range of other officers; some of these posts are moribund, such as that of the cathedral barber. The cathedral has a workforce of over 300 (many of whom work part-time), and approximately 800 volunteers. Dean and Chapter As of 1 August 2022: Dean – David Monteith (since 17 December 2022) Archdeacon of Canterbury and Canon Residentiary – William Adam (Archdeacon and Canon since 18 July 2022 collation) Canon Librarian – Tim Naish (since 22 April 2018) Canon Missioner – Emma Pennington (since 16 March 2019) Canon Treasurer (Diocesan Canon) – Andrew