Wychert
Wychert or witchert (with a number of variant spellings existing and meaning "white earth") is a natural blend of white chalk and clay which is mixed with straw to make walls and buildings, usually then thatched or topped with red clay tiles. This historic method of building construction is localised to Haddenham and the surrounding local area in Buckinghamshire. One of the largest known wychert structures is Haddenham Methodist Church.