Btu British thermal unit (replaced by kilowatt)
Casement The hinged and opening part of a window
Cavity closer Fitting or method of closing the cavity wall at peripheries of openings
Cavity tray A tray-shaped damp-proof course installed to cavity walls over a junction with the roof
Close-boarded roofs Where the rafters are clad tile side with timber boarding
Cappings Finishing pieces to cover joints and ends
Cold roof A roof that is insulated between the rafters or below them
Coping Weathering stone or course to the top of a wall
Corbelling Successive course-projecting brickwork
Crack vent Window casement stay that keeps it slightly ajar
Cresting Ornate ridge detail on a roof
Derating Allowing for insulation overheating in electric cables
Dessication Dried out subsoil causing shrinkage and subsidence
Dentil course Projecting course of stone or brick
DPM Damp-proof membrane beneath the base or slab finish
Dummy bars Fake glazing bars in windows (sometimes between the panes of double-glazing)
Eaves The lower edge of the roof
Fascia A horizontal decorative board fixed horizontally along the eaves to finish the roof edge
Fenestration Architecture of windows
Fielded panels Decorative relief work on wall panels
Finials Pointed ornaments on a gable end of a roof ridge
Flashings Weathering between roof sheeting and wall
Flemish bond Brick bond of alternate headers and stretchers in each course
Fletton Cheap brick
Glazing bars Slender sections used to support glass or plastic in windows or roofs
Header The end face of a brick
Horns Projection on the cill of a window or door frame to help build it into a wall
Joist A horizontal structural member of a floor or ceiling
Lead code The grade (thickness) of lead
Lead rolls Wood core rolls dressed with lead
Loop-in circuits Lighting circuit to reduce T-joints using ceiling roses
Low-e glass Low-emissivity (reflective) coated double glazing
Noggin A small piece of timber used between other main structural timbers to stiffen them
Parapet A low wall on the edge of a roof, balcony or gutter
Pitch The angle of a roof or rafters
Quoin Brick or stone set in the corner of a wall
Racking The result of wind pressure, causing a conservatory to lean
Radial circuits A spur circuit leading off a ring circuit without looping back
Rafters The sloping sections of a roof that support the glazing bars or tile battens
Rapid ventilation By a window or door opening vent or an electric fan
Ridge The apex of a roof
SAP rating Standard Assessment Procedure figure for valuing the energy efficiency of a dwelling
Snap header A half-brick (not a header)
Solvent-weld plumbing Glued permanent joints of plastic pipe
Stucco Smooth external plastering
Spalling Frost damage to bricks
Soakaway A large hole or chamber for draining rainwater into the ground away from the building
Soakers Undertile weatherings
Solar gain Extent of potential additional heating caused by the sun
Stretcher The long face of a brick
Terrazzo Coloured floor mosaic
Tie bar Steel bar between opposing walls or roof slopes installed to prevent them spreading apart
Tusk tenon Small tenon joint (often used on stairwell trimmer to trimming joists)
Trickle vent Background vent that can be left open and is secure
TRV Thermostatic radiator valve controlling radiator temperature
U value A measure of thermal transmittance through an element
Vertical DPC Damp-proof course incorporated within cavity closer
Verge The edge of a roof along the gable end
Voussoir A wedge-shaped arch brick
Warm roof A roof that is insulated on the top rather than between the rafters or below them
Wind post A vertical metal post incorporated within a wall structure to resist wind pressure
Y junction A y-shaped drainage piece for joining one run to another