A noble Council House on Sparkhill was both an advertisement for the County and a focus for local pride. But water and gas came from Birmingham, as did most of the new Yardleians. These amenities made possible the enormous increase in population (from ten to sixty thousand) in the three decades from 1880. Terrace streets were quickly built and occupied at Stechford and Hay Mill(s), up Red Hill, between Church Road and Yew Tree Lane, on Church Road, Clements and Stuarts Roads. Even in the village two crofts were crammed with tunnelbacks, three short rows of them.

The Great Trust had presented the District Council with several pieces of land, forty acres in total, for use as recreation grounds. A large piece of Church Field and a small one of Stichford Field were among them. The only ones to be opened were Queens Road and Sparkhill Parks: the silted moat by the church was considered dangerous so it was infilled, but bordering trees and slight hollows still define it. The old almshouses were demolished and a new group with a hall opened at the north end of the village, in 1904.

Yardley voted to join Birmingham in 1911 and did so the following year, enjoying lower rating for the next fifteen years. Thereafter the ancient name has only geographical significance, referring to no more than a square mile of the parish and manor. The Corporation adopted a 1909 plan of the Rural District Council for the Cole Valley. It was decided that wherever industry and sewerage works did not prevent it, the valley would be kept as a green strip of meadows, with a riverside walk from Solihull Lodge to Sheldon. Seven decades on the work is nearly complete. The river had been somewhat straightened, removing the last refuges of fish (the last trout was taken from it in 1925), and two millraces have been infilled. Richmond Road, Bachelors Farm, The Riddings and Glebe Farm recreation grounds have been laid out and there are larger areas of green on the west and north banks.

To link up its outlying suburbs the Corporation established the Outer Circle bus route in 1926, having drained, tarmac’ed and lit the lanes it used. This brought public transport to - or near - Yardley Village for the first time, so that it became suitable for private development. About Stechford a further fillip to urbanisation was the extension of Bordesley Green East across the Cole so that trams could reach Stuarts Road (1928). The landscape of Church End changed radically between the Wars. Villas and mansions largely disappeared, giving place to short streets of semi's. Only The Grange survives, as a Convent. The Croft is remembered in a new name for an old lane. The Grove (alias The Poplars) has gone but its lodge still stands just off Barrows Lane. Rockingham and Yew Tree Houses are recalled in street names, as are Flaxley, Fieldhouse, Glebe Farm, Lea Hall and Hillhouse (Old Farm Road). Millhouse Road follows the line of the infilled headrace to Wash Mill. Bachelors Farm gives its name to a play area. Folliotts (of Blakesley Hall) and Grevises (of Moseley Hall, former lords of Yardley) were honoured, if that is the right word, in the 1930s and 1960s respectively - but not the Taylors. The hamlets of Lower Stichford and Yew Tree vanished along with many farms and cottages. Starting in Lyttleton Road in 1920, huge council housing estates were to be built in two periods. These were Fast Pits and Hobmoor (2200 houses) and Manor Road in the 1920s, and after a break due to the Depression, Riddings, Glebe Farm and Lea Hall from 1933. The latter estates were not complete when World War Two started. Glebe Farmhouse was demolished c. 1934 and Lea Hall in 1937 when the railway station was built in the cutting beside it. The gate pillars long survived.

New estates were fitted in between old lanes, which were improved. New highways - Berkeley Road East/Millhouse Road, Audley/Kitts Green Roads, Wyndhurst/Bushbury Roads, and the part-new, part-old Manor/Inglefield/Lea Hall Roads and Flaxley/Folliott/Mirfield Roads, Wash Lane/Richmond Roads, Yew Tree Lane/Richmond Road - supplemented existing through routes. Holloways were infilled, hedged banks removed, streets were sewered, mained, paved, and lit with gas lamps. Part of Old Yardley Green Road was abandoned. Early estates were on straight or gently-curving streets, nearly all of them open at both ends. Later street-plans were circles, arcs, quadrants, and included short cul-de-sacs. 'Greens' were provided, but amenities were few and peripheral. Cinemas opened at Stechford and opposite the Swan, which was again rebuilt. Palatial pubs were built or re-built on bus routes: they had rooms and halls for every social function. Private development was to cover large areas of former farmland between Stuarts/Clements Roads and the eastern boundary, and from Stechford on both sides of the railway to and along Church Lane. Much space was left as nurseries, allotments, and sports grounds. Industry spread at Stechford, rail-served, and began on a designated site at Lea Hall/Kitts Green. Trolley-buses replaced tramcars and went on to the 1931 boundary at Hatchford Brook in 1933. Diesel buses plied on several cross-Quarter routes.