See caption
Close-up of part of the curtain wall at Tonbridge Castle in Kent, built using ashlar blocks made of local red sandstone
Source: Wikimedia Commons

Ashlar is masonry of squared and finely cut or worked stone,[1] commonly used as the facing for a building.[2] The term is also used to describe thin slabs of similar masonry used to face a brick wall or as paving slabs, although they are more properly referred to as bastard ashlar.[1]

The technique of building using dressed stone blocks has been in use since at least the time of the Romans, who called it opus quadratum;[1] it was introduced into Britain by the Normans.[3]


In the movement known as Speculative masonry,[4][a]Operative freemasons actually worked with stone, as opposed to Speculative masons, who use “the tools and skills of operative masons as metaphors for living a good life”.[4] ashlars are a metaphor for a member’s personal development. The rough stone taken from the quarry symbolically represents the freemason prior to his or her initiation. After having been smoothed and dressed by experienced masons, the resulting smooth ashlar represents the diligent initiate who has been taught the lessons of Freemasonry, and goes on to live an “upstanding life”.[5]




Curl, James Stevens, and Susan Wilson. “Ashlar.” The Oxford Dictionary of Architecture, Online, Oxford University Press, 2021,
Gorse, Christopher, et al. “Ashlar.” A Dictionary of Construction, Surveying and Civil Engineering, Oxford University Press, 2020,
Hey, David. “Ashlar.” Oxford Companion to Local and Family History, Online, Oxford University Press, 2009,
Masonic Lodge of Education. Rough and Perfect Ashlar.
Staff writer. “Operative V. Speculative.” Today in Masonic History, 20 May 2019,