In July 1966, the council approved the construction of the £.5 million estate. Work began on the Ashfield Valley estate in April 1967 with the first flat ready to let by 1968 and the entire project complete by 1969. Ashfield Valley was a deck access estate built by Cruden construction in accordance with the Swedish 'Skarne' method of building. The estate comprised 1,014 flats in 26 blocks ranging from 4 bedroom family homes to bedsits. The flats were contained in a series of blocks with two-storey structures along the edges of the valley, gradually dropping to a maximum of seven-storey buildings at the deepest points. The development was planned to divide into two sections – one on each side of the valley – with a play area placed in the middle to keep traffic out. 40% of the residents would have access to garages.
The blocks were given names corresponding to letters of the alphabet going from A to Z (eg. A was Appleby, B was Buttermere, Z was Zennor etc), however nobody could think of a suitable word beginning with X for the 24th block so it was named 'Exford'.
The estate was initially popular, like many housing estates at the time, but quickly declined and by the 1980s was a haven for drug users, glue sniffers and squatters as well as being home to a large number of families, OAP's and single people. Tenants complained that they suffered from discrimination in the job market as well as encountering difficulties obtaining credit. A study by The Rochdale Observer, in which undercover journalists attempted to obtain goods on HP from town centre retailers using Ashfield Valley addresses, found tenants fears to be largely true.
The Rochdale author Trevor Hoyle's novel Rule Of Night is largely set on Ashfield Valley.
In January 1987, frozen water pipes cracked, flooding 15 of the 26 blocks. Many of the tenants were evacuated, with some having to sleep in a local church. 23 blocks were demolished in 1992 with the remaining 3 being renamed Stonyvale Court. These blocks stayed under council control and are very popular with tenants. The rest of the estate is now a business park, complete with an Odeon cinema, a B&Q and a McDonalds restaurant.