Glossary | Domestic Buildings Research Group (Surrey)

There are many technical terms used to describe the multitude of architectural features, although many are just variations of the basic terms.

We base our terminology on the illustrated glossary produced by the Council for British Archaeology ‘Recording Timber framed buildings’. We have extended this for Surrey buildings and produced an illustrated glossary for:-

Larger two-bay open-hall houses (pre1440)
Smaller one-bay open-hall houses (post 1440)

with definitions of each term included.

You can purchase a copy of ‘Recording Timber Framed Buildings: An Illustrated Glossary’ from the Council for British Archaeology website.

There are other good online glossaries on the Vernacular Architecture Group and BARD websites.

(Click/tap image to enlarge)

Illustrated glossary - stops, joints, scarfs and joists — (Click/tap image to enlarge)

DBRG Glossary of Terms

Term	Definition
aisle	The portion of a house or barn separated only by posts from the main body of the building but under the same roof (like some church aisles).
ashlar	Vertical timber rising in line with the inner face of a wall forming a triangle between the rafter and the horizontal
bay	The portion of a building between adjacent principal posts or principal rafters of a box-framed building.
half-bay	Short bay often used for a smoke bay or chimney.
smoke bay	Short bay used for a hearth with closed partitions to confine the smoke.
beam	Major horizontal timber.
cross beam	Ceiling beam across the width of a house. Sometimes called a transverse beam.
spine beam	Ceiling beam along the length of a house. Sometimes called an axial beam.
dragon beam	Horizontal timber which runs diagonally over a corner post, into which floor joists are tenoned to allow adjacent walls to be jettied.
girding beam	Horizontal beam in a wall frame at the level of an upper floor.
brace	Timber, curved or straight, running between vertical and horizontal members of a frame.
arch brace	Brace running from vertical timber such as a post to a higher horizontal timber such as a wall plate. Sometimes called a head brace.
(long) passing brace	Long brace from the head or foot of a principal post to the ground sill or wall plate, halved across a girding beam.
down brace	Brace running from a vertical timber such as a principal post to a lower horizontal timber such as a girding beam. Sometimes called a tension (or foot) brace.
bressumer	Horizontal beam above a fireplace or set forward to support a jettied wall.
chamfer	Angled surface formed by cutting off the long edge between two faces of a timber, usually at 45º.
collar	Transverse timber connecting rafters at a point above their feet and below the apex of the roof.
cranked	Used of a timber with a pronounced change of angle such as a tiebeam higher at its centre than at its ends.
cross entry	Entry through opposed front and back doorways but with no wall to separate it from the hall. If separated by a wall it is called a cross passage, which is rare in Surrey.
overshot cross entry	Where the first floor overshoots the cross entry below.
cruck	A pair of curved timbers (blades) serving as the principals of a roof with a variety of arrangements to form a truss.
dais	Originally a raised platform at the upper end of the hall. Now used as shorthand for the moulded beam at the upper end of an open hall. A bench was normally fixed to the upper end wall below the beam.
durn door	Doorway made by pairing two timbers halved from a naturally curved timber.
end	The distinction in the plan of a house between the private and the service rooms.
low (or service) end	The end of the house used for service rooms or of the hall towards that end.
upper (or high) end	The end of the house used for private rooms or of the hall towards that end.
face	A frame is marked up as if it were lying on the ground.
upper or fair	The upper or fair face is on top and timbers are set flush with one another so that it is the best side. The pegs are driven in from this side which has the assembly marks on it
lower	The lower face is underneath and timbers will not be flush.
fillet	A narrow flat architectural member.
gablet	A small gable above a hip.
garderobe	A small privy projecting from an upper storey.
ground sill	Horizontal timber at the bottom of a framed wall into which posts and studs are tenoned. Sometimes known as a sole plate.
hall	Traditional term for the main living room of a house.
open hall	Where the hall is open to the rafters and has an open hearth. Can be one or two bays, occasionally more.
half-floored hall	Open hall where one bay is floored to give it an upper storey and the other is open to the rafters.
jetty	Cantilevered overhang of one storey over the storey below it.
internal jetty	Where the first floor internal partition overhangs the ground floor wall below it, giving a larger hall without forfeiting space upstairs.
joist	One of a series of horizontal timbers supporting a floor or carrying a ceiling.
jowl	Expansion of the inner face of the top of a bay post to accommodate housings for wall plate and tiebeam.
mortice	Socket in a timber to receive a tenon of another to form a joint.
mullion window	Window with vertical timbers in the opening rather than glass.
oriel window	A projecting window not reaching the ground.
pentice	Narrow roof projecting from a wall.
post	Vertical timber, usually substantial and usually forming part of the main framework (cf stud).
principal/bay post	Main post rising the full height of a building on the line of the tiebeams.
crown post	Upright timber standing on a tie beam supporting a collar purlin and not rising beyond the collar.
king post	Upright timber from a tiebeam or collar to the apex of a roof to support a ridge piece. Can rest on the tiebeam or be suspended from the apex.
queen post	Paired posts set on a tiebeam and directly supporting purlins.
purlin	Longitudinal timber set in the plane of a roof slope and supporting common rafters.
butt purlin	Purlin tenoned into principals at either end of a bay.
staggered butt purlin	Purlin tenoned into principals but staggered at different levels to avoid weakening the timbers.
collar purlin	Purlin supported by crown posts and bearing the collars. Sometimes called a crown plate.
clasped purlin	Purlin supported by a collar, queen post or raking strut.
rafter	Inclined timber, usually one of a pair, which supports laths/battens under the roof covering.
common rafters	Rafters of uniform size regularly spaced along the length of a roof, or intermediate between principals. A common-rafter roof is a roof in which only common rafters are used.
principal rafter	A rafter which is part of a truss, as opposed to the common rafters in between the trusses.
diminished principal rafter	In a roof with clasped purlins, a principal cut back above the purlin to the thickness of a common rafter.
rail	Horizontal timber of wall frame between posts or studs.
mid rail	Beam in a wall frame centrally place in a storey or between sill and wall plate in an open hall.
ridge board/piece	Longitudinal timber at the apex of the roof.
roof
gabled roof	Where the end of a roof is vertical rather than sloped.
hipped roof	Where the end of a roof is sloped towards the apex.
half-hipped roof	Where the end of the roof is partly vertical and then slopes towards the apex.
saddle	Short timber set on top of two cruck blades.
scarf joint	Joins the ends of two timbers to make a longer structural member.
smoke hood	Timber framed structure within a bay, supported on a bressumer and tapering to an outlet in the roof, to contain smoke from the hearth.
soulace	Straight brace from rafter to collar in a common rafter or crown post roof.
spere	Short screen to stop a draft from a doorway, typically used with an overshot cross passage.
stop	Decorative ending of a chamfer on a beam, doorpost etc. to return the timber to a square section.
strut	Timber in compression, normally between tiebeam and collar or principal rafter.
upright queen strut	Paired struts framed between tiebeam and collar and not supporting a longitudinal timber.
raking queen strut	Paired struts, straight or curved, set at an angle to the tiebeam and framed into the principal rafter.
crown strut	Upright timber similar to a crown post but not supporting a collar purlin.
spandrel strut	Short timber set in the spandrel of an arch brace between the brace and the bay post or tiebeam.
stud	Subsidiary vertical timber, in a framed wall or partition.
close studding	Where the spaces between studs are approximately the same width as the studs.
tenon	Projection from the end of a piece of timber to fit into the socket (mortice) of another to form a joint.
tiebeam	Main transverse timber connecting the tops of walls.
truss	Rigid cross-frame from tiebeam to ridge constructed at bay intervals to carry longitudinal timbers that support common rafters.
open truss	Where there is no wall in between the timbers of the truss to allow free movement.
closed truss	Where there is walling between the timbers of the truss to separate the bays and to prevent smoke escaping into the next bay.
fan truss	A truss with a collar with a central strut to it (like a crown strut) but also raking queen struts. Sometimes called a butterfly truss.
wall plate	The plate on top of a wall frame or a masonry wall, on which roof trusses and rafters rest.
windbrace	Brace in the plane of the rafters, tying together a principal and a purlin.
wing
cross-wing	Section of a house roofed at right angles to the adjacent main range. The main roof will typically oversail the wing up to the ridge of the wing’s roof.
face-wing	Section of a house built onto the face of a building. The roof will typically fit on top of the rafters the main roof.