Upon moving to London in 1808 David Napier started work within the advanced engineering workshops run by Henry Maudslay. By 1815 he was occupied as a Work's foreman near Fleet Street. In 1817 he was the engineering partner in a stationer's business known as Messrs Baisler & Napier Engineers located in Lloyds Court, Soho. David terminated the partnership and became self employed and moved to a larger workshop at 15 Lloyds Court, Crown Street in Soho.
In March 1832 David moved to more spacious works south of the Thames in Lambeth. His new residence was in York Road, Lambeth with his works entrance through a gateway off the narrow Vine Street.
The business remained in this building in until 1903 when it was moved to a large 4-acre site at the Vale in Acton, West London from which the business steadily developed.
As well as manufacturing cars at Acton, in 1904 DNS also set up an assembly shop in the USA setting up the America-Napier Company which survived until 1912.
With World War II looming the Air Ministry needed to expand aircraft engine production. As such D.Napier & Son saw major investment and expansion as follows:
1938 Park Royal Works - Engine test houses
1938 Aldenham (former London Underground train shed) - Open air 'propeller stand' engine test
1938 Luton Airport - DNS Flight Development Establishment
1939 Earls Court Arena - Wartime engine overhaul and engine rebuild
1939 East Lancashire Road Works, Liverpool - Wartime shadow factory
1947 Napier Research Station
1947 Raynes Park - Ex-British Salmson premises