From the 1840s to the 1860s, around 80% of the cottages in Thorney village (a little later in many of the farms on the Fen) were rebuilt to meet the high standards of the Russell family. Even older cottages which were kept often had new outbuildings added to give hygienic kitchen and toilet facilities - by the standards of the times. While the new houses gave an attractive appearance appreciated by travellers through the village, they were also of a higher quality than many village homes elsewhere. Each new house also had an allocated third of an acre of land, so the tenant could grow food and keep a pig, helping to support the family.
From the front, Samuel Sanders Teulon and architects who followed him built regular but picturesque blocks of cottages, typically seven dwellings in a row. Have you noticed that no row is identical to another? They had different details of window shapes, porches and gables to add interest. However, the houses often varied in size, even if that wasn't clear from the front elevations, and some are still very small, with one bedroom.
Over the last century, especially as the houses have become owner-occupied rather then rented, individuals have adapted and extended their homes in order to make them more spacious and convenient. Some small houses have been joined together internally, though planning and design rules mean this is not shown on the outside. A wide variety of extensions have been added at the rear of the properties, all at different times, and this makes some maintenance difficult!
In general terms, cottages in the historic centre of the village and along to the Medical Centre are Listed Buildings, which restricts work which can be done inside and outside them. Cottages east of the Medical Centre for the next five rows are covered by an Article 4 Direction which means that the outside of them, from any viewpoint, is protected.