Latrines are usually called garderobes in historical fiction, but they had other names – Gang, orgong, cloacum, neccessarium, reredorter and jake, which is the French form of john or jonny. The Welsh used tŷ bach (it means a small or private place). Another popular name was the privy.
Privies varied from a hole in the ground to grand, purpose built structures – a wooden bench with a hole cut into it, or sometimes stone seats, inside a small, private space. Lids with handles were used to drop across the hole, and earth or sand was kept to throw in; often both were required in an effort to dampen the smells. Henry VIII had sand in his jake at Dover Castle. Gongscouring was a recognised trade by the 16th century. I don't know about you, but can't help but shudder at the thought of a stone toilet seat on a frosty January morning...
Usually the latrine cubicle projected out over the castle walls, and excrement piled up below. Someone (the poor gongscourer) had to go around at frequent intervals and shift it. Sometimes a chute or shaft inside the walls drained into a cesspit. In this case, latrines were necessarily grouped together at one spot in the castle. Rainwater was often directed from rooftops to the chutes to clean them out. Hampton Court had a communal House of Easement which was two stories high. “Pissing places” were common and at Greenwich Palace an effort was made to stop this habit by whitening the walls and painting red crosses on them in the belief that no Christian would piss against the Holy Cross.
From the 15th century on, toilet arrangements within private chambers featured a chair or stool with a pot included below the seat – a close stool – and the pot would be regularly cleaned out by servants. (I imagine they emptied the contents over the castle walls! Certainly that happened at Stirling Castle in the sixteenth century.)
Water was a necessity for life within the castle. Several wells were included at most residences. The deepest well in England goes down 330 feet, (100 metres) and such depth requires a mechanism to lift the heavy bucket full of water to the surface. Systems of pulleys and counter balances were used. Rainwater was also stored in cisterns at roof level and lead pipes were in use from 1300 onwards.
Fireplaces have been found in English castles as early as 1081, but they were unlike modern fireplaces in that they projected out into the room they heated, and they did not have a chimney. The smoke escaped through small holes in the external wall at the back of the fireplace. By the early twelfth century, builders had devised a flue that carried smoke to an external chimney on the roof. By the fourteenth century, fireplaces lost their projecting hoods and were recessed into the wall, usually on a long wall, and often off-centre, so they were closer to the “higher” end of the hall. In France, the practice was to place the fireplace behind the dais, thus keeping the noble family warm.
Decoration included abstract patterns cut into the stone in the twelfth century and heraldry made its appearance in the later middle ages. The decoration of fireplaces never transferred to internal doorways in English architecture, possibly because wall hangings and tapestries often obscured doorways. In direct contrast, the French habit, commonplace by the fifteenth century, was to extensively decorate door mouldings.
Lighting was difficult in castles. Most light sources were portable, either suspended as chandeliers of wood, brass or iron. Small wall niches are found in stone walls of corridors and latrines. Lamps could be mounted on projecting brackets in smaller chambers, usually to either side of the fireplace.