The building of the estate caused a huge increase in population density, which led to demands on services and reforms of local government. An additional 1,000 houses were added in later phases. The estate had no industrial and very little commercial development until the May & Baker and Ford Dagenham sites opened nearby, and a shopping area was built at Heathway. The estate has formed part of Greater London since 1965, when the Barking section was combined with Dagenham, and has been within a single London borough since boundary changes caused the Ilford section to be transferred from Redbridge to Barking and Dagenham in 1994.
The estate is named after the ancient Becontree Hundred, which historically covered the area. It is recorded in the Domesday Book of 1086. The name is Old English and means 'tree of a man named Beohha'. The tree would have stood on Becontree Heath, just outside the eastern boundary of the estate. The majority of the estate was in the parish of Dagenham and the whole estate is in the Dagenham post town, and the two names are used interchangeably.
Because of the lack of available land in the County of London, the Housing Act 1919 permitted the London County Council (LCC) to build housing and act as landlord outside of its territory. On 18 June 1919 the London County Council's Standing Committee on the Housing of the Working Classes resolved to build 29,000 dwellings to accommodate 145,000 people within 5 years, of which 24,000 were to be at Becontree. Becontree was developed between 1921 and 1935 as a large cottage estate of around 26,000 homes, intended to be "homes fit for heroes" for World War I veterans.
Most of the land was at that time was market gardens, with occasional groups of cottages and some country lanes. It was compulsorily purchased. 4,000 houses had been completed by 1921. The early residents were able to pick rhubarb, peas and cabbages from the abandoned market gardens.