In Britain, the period from c. 800-600 B.C. to the coming of the Romans. Also used for those un-Romanized native communities which survived until the Saxon incursions, especially beyond the Roman frontiers.
Italianate
A style of classical secular architecture at its peak in the early to mid-19th century, derived from the palaces of Renaissance Italy, but often varied by asymmetrical elements.
Jack arch
Shallow segmental vault springing from beams, used for fireproof floors, bridge decks, etc.
Jacobean
Yorkshire (West Riding)
The style of early 17th-century England, called after James I (reigned 1603-25), but common into the middle decades. Not always distinguishable from the preceding Elizabethan manner, with which it shares a fondness for densely applied classical ornament and symmetrical gabled façades.
Jacobethan
A late-19th-century coinage for the revived Elizabethan or Jacobean styles.
Jamb
(lit. leg): One of the vertical sides of an opening. Also (Scots) a wing or extension adjoining one side of a rectangular plan, making it into an L-, T- or Z-plan.
Jetty
In a timber-framed building, the projection of an upper storey beyond the storey below, made by the beams and joists of the lower storey oversailing the wall; on their outer ends is placed the sill of the walling for the storey above.
Jib door
A concealed door, made flush with the wall surface and treated to resemble it; sometimes spelt gib door.
Joggle
The joining of two stones to prevent them slipping, by a notch in one and a projection in the other; hence joggling.
Jointed cruck
A type of timber construction in which the main supports or blades are formed from more than one timber; the lower member may act as a wall-post; it is usually elbowed at wall-plate level and jointed just above.