The building was replaced by a new building, New Little Mill, five storeys high, four shorter than its predecessor but occupying a larger area of ground. The new mill had concrete floors and was designed to use mains electricity. The building is the earliest mill in Greater Manchester that was built to use mains electricity. An 1891 Ordnance Survey map shows that the arm on the Rochdale Canal had been filled in and the complex's canal basin had been retitled as a "reservoir", suggesting that the canal had ceased to be used as a way of transporting goods to and from the complex. By 1902, the canal basin had been filled in, however exactly when it was filled in is unknown. Between 1902 and 1903, Old and Decker Mills were reduced in height by 1 storey to 7 storeys and New Mill was reduced in height by 2 storeys to 6 storeys. The exact reason for this reduction is unknown, however, it is speculated that the structure of the buildings was struggling to cope with the weight of increasingly heavy machinery. This theory is given added weight by the fact that at around the same time the timber beams used to support ceilings were replaced with steel beams to strengthen the building. In 1930 the Bengal Street block was also reduced in height by 2 storeys and buttresses were constructed against the south wall of Decker Mill. By the 1940s Fireproof Mill and Doubling Mill were occupied by a bedding manufacturer. In 1948, the break-up of the main site began with Old Mill and Decker Mill being sold, with the Murray Street block following in 1950, and the Bengal Street block in 1960. Old and Decker Mill were used as a warehouse after 1954 and later used by several clothing manufacturers. Although some work was done to strengthen the structure in the 1960s, the complex was allowed to fall into disrepair. Also during the 1960s, some sections of the complex began to be left unoccupied and others burned down including an engine block. During this period, parts of the complex were used for light industrial use before they too fell into disuse. In the 1990s, the buildings fell victim to vandalism and arson that threatened to destroy what remained of the site. In 2000, Total Architecture appointed Urban Splash to convert Fireproof and Doubling Mill into office space. On completion in 2003, the conversion received a RIBA Award. The North West Development Agency used a compulsory purchase order to take control of the main site in 2003. This allowed the Heritage Lottery Fund to give a £7.164M grant towards the restoration of the complex.