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William Sugden set up an architectural practice in Leek in around 1850 after being involved with the design of stations on the Churnet Valley line. His son, William Larner Sugden joined the practice in 1866, becoming a partner in 1881.
The firm developed a distinctive style, particularly following Larner Sugden's involvement in the Arts and Crafts movement under the influence of William Morris, who spent considerable periods in Leek researching dyes and dyeing for his textiles. The Arts and Crafts style appears particularly in the detailing of buildings from the mid-1870s onwards. The practice's output ranges from the largest of the silk mills (Big Mill) to humble terraced houses.

Listed buildings and structures are officially designated as being of special architectural, historical or cultural significance. There are over half a million listed structures in the United Kingdom.
Listed status is more commonly associated with buildings or groups of buildings, however it can cover many other structures, including bridges, headstones, steps, ponds, monuments, walls, phone boxes, wrecks, parks, and heritage sites.

In England and Wales there are three main listing designations;
Grade I (2.5%) - exceptional interest, sometimes considered to be internationally important.
Grade II* (5.5%) - particularly important buildings of more than special interest.
Grade II (92%) - nationally important and of special interest.

There are also locally listed structures (at the discretion of local authorities) using A, B and C designations.

In Scotland three classifications are also used but the criteria are different. There are around 47,500 Listed buildings.
Category A (8%)- generally equivalent to Grade I and II* in England and Wales
Category B (51%)- this appears generally to cover the ground of Grade II, recognising national importance.
Category C (41%)- buildings of local importance, probably with some overlap with English Grade II.

In Northern Ireland the criteria are similar to Scotland, but the classifications are:
Grade A (2.3%)
Grade B+ (4.7%)
Grade B (93%)

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