Born in Norfolk, United Kingdom, studied at the Plymouth School of Architecture 1968-71 and the University of East London 1973-5. Qualified at the Royal Institute of British Architects with distinction in 1976. He is a registered architect in the RIBA and the Ordem dos Arquitectos (OASRS) in Lisbon since 1979.

After a brief stint working in London and Accra, Ghana, he arrived in Portugal at the end of 1976. He worked in Lisbon ateliers until 1981, when he began to work with B.D.P’s Lisbon office (Building Design Partnership, Lisbon).

In 1983, he co-founded St. George e Sinclair, Projectos de Arquitectura e Design where they designed the first HQ building for B.P.I. (Banco Português de Investimentos), and HQs for T.M.G. (Têxtil Manuel Goncalves), R.A.R. (Refinarias de Açúcar Reunidas) and Barclays Bank.

In 1992/3 he founded David Sinclair e Associados Arquitectos, Lda. and has been working with a strong emphasis on toursim and leasure sectors ever since.

The projects he has developed pass from new build to conservation and re-use of existing historic buildings.

In Africa, he has developed major projects for Luanda, São Tomé, Cabo Verde and, more recently, Burkina Faso, Senegal and Conakry.