Dean established his architectural practice in London in 1987. Over thirty years he designed a series of major buildings including commercial offices and luxury hotels. In 2004 he and his family witnessed first-hand the effects of the Tsunami in Sri Lanka. This roused his interest in trying to help poor and vulnerable children which led to establishing DATUM. Since taking early retirement he has been able to dedicate more of his time to working on the charity’s projects. As Trustee he has used his experience in building design and project management to construct schools and clinics across SE Asia and sub-Saharan Africa.