Property Survey & Valuation Glossary
A comprehensive A to Z guide to the terminology used in property surveys, building inspections and residential valuations. Written in plain English to help you understand your survey report and make informed property decisions.
A
Abutment
The junction where a roof meets a wall or another roof. Abutments are common points of water ingress and are closely inspected during building surveys.
Air Brick
A perforated brick or grille built into a wall to ventilate the space beneath a suspended timber floor. Blocked air bricks can lead to rot in floor joists and are noted on all levels of survey.
Artex
A textured wall and ceiling coating popular from the 1960s to 1980s. Older Artex may contain asbestos fibres. Our surveyors will note its presence and recommend sampling if the property predates 2000.
Asbestos
A fibrous mineral used extensively in building materials until 1999. Common in ceiling coatings, pipe lagging, floor tiles, roof sheets and flue pipes. A survey will flag suspected asbestos containing materials and recommend a specialist asbestos survey where necessary.
Ashlaring
The timber framework used to finish a dormer window or attic room, particularly in Scottish and period properties. Decay in ashlaring can affect the structural integrity of roof spaces.
B
Bay Window
A window that projects outwards from the main wall of a building, creating a recess inside. Bay windows, particularly in Victorian and Edwardian properties, are inspected for structural movement, rot in timber frames and thermal efficiency.
Bressummer
A heavy horizontal beam spanning a wide opening such as a shopfront or bay window. Often timber in period properties. Failure of a bressummer beam is a serious structural defect requiring specialist repair.
Bridging
A method of spanning between floor or roof joists to stiffen the structure. Also refers to cavity wall bridging — where material in a wall cavity allows damp to cross from the outer leaf to the inner leaf.
Building Regulations
Statutory standards for the design and construction of buildings in England and Wales, covering structure, fire safety, drainage, ventilation and energy efficiency. A survey will note obvious non-compliance where visible but is not a building regulations inspection.
Building Survey
The most comprehensive type of home survey, formerly called a Structural Survey and now known as the RICS Level 3 Home Survey. Suitable for older properties, listed buildings, buildings of unusual construction, properties in poor condition or those planned for major alteration. Provides a detailed report on condition and repair.
C
Cavity Wall
A wall constructed of two parallel masonry leaves with a gap (cavity) between them, introduced widely from the 1930s. The cavity prevents moisture crossing from the outer face to the inner face. Cavity wall insulation, where retrofitted, is assessed for adequacy and damp bridging risk.
Cavity Wall Tie
Metal ties spanning the cavity to connect the two leaves of a cavity wall. In properties built before the 1980s, ties may be of mild steel and prone to corrosion. Expanding corroded ties can crack the outer leaf horizontally — a condition called cavity wall tie failure.
Chipboard
A manufactured sheet material made from compressed wood particles and resin, widely used for flooring from the 1970s onwards. Older chipboard floors can weaken when exposed to moisture and may need replacement.
Condensation
Moisture that forms when warm, moisture-laden air meets a cold surface. The most common cause of dampness in UK homes, often mistaken for rising damp. A survey will distinguish condensation from penetrating or rising damp and advise on ventilation and heating improvements.
Coping
The protective capping on top of a wall, parapet or chimney stack, usually of stone, concrete or metal. Damaged or missing copings allow water into the wall below and are a common defect noted during surveys.
D
Damp Proof Course (DPC)
A horizontal waterproof barrier installed near the base of walls to prevent ground moisture rising into the building. Modern DPCs are of bituminous felt, plastic or engineering bricks. In period properties, slate courses were common. A bridged or failed DPC is the most frequent source of rising damp.
Damp Proof Membrane (DPM)
A waterproof sheet laid beneath a ground-bearing concrete floor slab to prevent moisture rising through the floor. Failure or absence of a DPM leads to damp concrete floors and can affect floor coverings, timber skirtings and internal air quality.
Deathwatch Beetle
A wood-boring beetle that attacks damp, partially decayed hardwood — typically oak in historic buildings. The name comes from the tapping sound the beetle makes, once associated with death vigils. Requires specialist timber treatment.
Deflection
The amount a structural member bends under load. Excessive deflection in floors, beams or lintels indicates undersized or overloaded structural elements and is a significant survey finding.
Dormer
A window projecting vertically from a sloping roof, with its own roof and side walls. Dormers are inspected for leaks at the junction with the main roof, rot in timber cheeks and adequate insulation.
E
Eaves
The lower edge of a roof where it overhangs the walls. Eaves carry the guttering and provide ventilation to the roof space. Rot in eaves timbers, blocked ventilation and defective guttering are all noted during surveys.
Efflorescence
A white, powdery salt deposit that appears on masonry surfaces when soluble salts migrate to the surface as the wall dries. Efflorescence is cosmetic and brushes off; it is distinguished from more serious salt crystallisation behind paint finishes.
Engineering Brick
A dense, high-strength brick fired at high temperature with low water absorption. Engineering bricks are used below ground level, in damp proof courses and in retaining walls. They are graded Class A (highest strength) or Class B.
English Bond
A traditional bricklaying pattern alternating courses of headers (short face) and stretchers (long face). Common in pre-19th-century buildings and often indicative of a solid (non-cavity) wall construction.
F
Fascia
The vertical board fixed to the eaves of a roof, to which guttering is attached. Fascia boards are typically timber or uPVC. Rot in timber fascia boards is common and can allow water into the roof structure.
Filleting
A mortar or mastic seal at the junction of a roof covering and an abutment wall. Filleting degrades over time and is a frequent source of water ingress, particularly on older properties with parapet walls.
Flashing
A strip of metal (usually lead, zinc or aluminium) used to seal roof junctions — around chimneys, at abutments and in valleys — to prevent water ingress. Damaged, missing or poorly installed flashing is one of the most common defects found in building surveys.
Flemish Bond
A bricklaying pattern alternating headers and stretchers within each course. Common from the 17th century onwards and often found in Georgian and Victorian townhouses.
Flue
The pipe or chimney passage that carries combustion gases from a boiler, fire or stove to the outside. Flues are inspected for integrity, adequate lining and compliance with current ventilation and safety standards.
Foul Drainage
The system of pipes carrying wastewater from WCs, sinks, baths and showers to the public sewer or a private treatment system. Blocked or defective foul drainage is investigated during a survey where accessible.
Foundation
The load-bearing base of a building, typically concrete strip, trench fill, raft or piled. Foundations are generally below ground and cannot be inspected during a non-intrusive survey, but signs of foundation failure — such as subsidence cracking — are assessed.
G
Gable
The triangular upper portion of a wall at the end of a pitched roof. Gable walls are inspected for structural stability, cracking, damp penetration and adequacy of restraint straps tying the wall to the roof structure.
Ground Heave
The upward movement of the ground beneath a building, usually caused by clay soil rehydrating after the removal of a large tree. Heave can lift foundations and crack walls — it is the opposite mechanism to subsidence, though the damage can appear similar.
Gully
A drainage fitting at ground level that collects surface water and/or wastewater and connects it to the underground drainage system. Blocked gullies cause localised flooding and damp near the base of walls.
Gutter
The channel fixed along the eaves of a roof to collect and direct rainwater to downpipes. Cast iron, uPVC and aluminium are common materials. Blocked, leaking or incorrectly profiled gutters cause penetrating damp and can saturate walls over time.
H
Header Tank
A small water storage tank, usually in the loft, feeding the hot water cylinder and central heating system. Modern combination boilers eliminate the need for header tanks. Leaking or poorly insulated tanks are a common survey finding in older properties.
Hip
The sloping edge where two roof planes meet at an external angle, as distinct from a ridge (horizontal) or valley (internal). Hip tiles and the leadwork at hips are inspected for displacement and water ingress.
HomeBuyer Report
A mid-level survey format previously offered by RICS, now largely superseded by the RICS Level 2 Home Survey. Provides a concise assessment of condition using a traffic light rating system for standard construction properties in reasonable condition.
Honeycombing
Voids in concrete caused by inadequate compaction during pouring, leaving a honeycomb-like surface. In reinforced concrete structures, honeycombing exposes the steel reinforcement to moisture and corrosion.
I
Infill
Material or construction used to fill the space between structural frame members. In timber-framed buildings, infill may be wattle and daub, brick nogging or modern panel systems. Condition of infill affects thermal performance and weathertightness.
Inspection Chamber
An access point, typically a manhole, where sections of underground drainage meet, allowing inspection, testing and rodding of the drainage system. Our surveyors lift accessible inspection chambers to check drainage flow direction and condition.
Interstitial Condensation
Condensation that forms within the layers of a building element — for example, within a roof or wall — when warm moist air penetrates the construction and meets a cold surface inside the structure. It can cause hidden rot and is a particular concern in poorly insulated buildings.
J
Jamb
The vertical side of a door or window opening. Jambs are inspected for cracking that may indicate structural movement, and for rot in timber window jambs where water has penetrated.
Joist
A horizontal timber or steel beam supporting a floor or ceiling. Joist ends built into external walls are vulnerable to rot where damp has penetrated. Bouncy or sagging floors often indicate undersized or decayed joists.
Junction Box
An enclosure housing electrical connections where cables are joined. Inaccessible junction boxes, poorly secured connections and outdated wiring are noted during surveys where visible.
K
Kerbing
The raised edging around a flat roof, typically where the roof meets a parapet or upstand. Lead or other flashing is dressed over the kerb to weather the junction. Poor kerb detailing is a common cause of flat roof leaks.
Key
The roughened or grooved surface that provides a mechanical bond between two materials — for example, plaster on brickwork, or render on blockwork. Loss of key causes plaster or render to debond and sound hollow.
King Post
A central vertical member in a traditional trussed roof, connecting the tie beam to the ridge. King post trusses are common in Victorian buildings. Splits, rot or insect attack in the king post are serious structural defects.
L
Lath and Plaster
A traditional ceiling and wall finish — thin timber laths nailed to joists or studs and coated with lime plaster. Common in pre-1940s buildings. Laths can lose their key over time, causing ceilings to sag or collapse, and are often replaced during renovation.
Lead Paint
Paint containing lead compounds, common in properties built before the 1960s. Lead paint is hazardous when disturbed, sanded or stripped. A survey will note its likely presence in older properties.
Lintel
A horizontal beam spanning a door or window opening, supporting the wall above. Lintels may be timber (period properties), stone, concrete or steel. Cracked or sagging lintels indicate structural movement and require repair or replacement.
Longhorn Beetle
A wood-boring beetle that attacks the sapwood of softwoods, primarily in roof timbers. Less common than woodworm but more destructive, as the larvae can tunnel extensively before emerging. Requires specialist treatment.
M
Mortar
The binding material between bricks or stones, typically a mix of cement or lime with sand and water. Mortar should be softer than the masonry it binds — excessively hard cement repointing of period properties can trap moisture and accelerate brick decay.
Movement Joint
A deliberate gap in a structure — usually filled with a flexible sealant — that accommodates thermal expansion and contraction, preventing cracking. Absent or failed movement joints cause cracking in long runs of brickwork or at junctions of different materials.
N
Newel Post
The main vertical post at the foot of a staircase and at landings where the direction changes. Newel posts carry the handrail and are structural. Rot at the base of a timber newel post, or looseness, is noted in a survey.
Nogging
Short horizontal timber pieces fixed between floor joists or wall studs to stiffen the structure and prevent joists twisting. Missing or inadequate nogging contributes to bouncy floors.
Non-Traditional Construction
A building constructed using methods or materials outside standard brick, block or timber frame — for example, concrete panel systems, steel frame, timber kits or no-fines concrete. Non-traditional construction affects mortgageability, insurance and repair costs and requires a specialist survey approach.
O
Oversite
The area of ground enclosed by the foundations of a building, typically covered by a concrete slab or suspended floor. The oversite is assessed for ventilation, damp proofing and any evidence of debris, vegetation or inadequate clearance.
P
Parapet
The section of wall extending above the roof line, often at the front of a building or between terraced properties. Parapet walls are highly exposed to weather and are inspected for cracking, leaning, damp penetration and adequacy of flashing and coping.
Party Wall
A shared wall between two adjoining properties (semi-detached or terraced). The Party Wall etc. Act 1996 governs works affecting party walls. Surveys do not inspect the neighbour's side but will note visible condition and any signs of shared defects.
Penetrating Damp
Moisture entering a building through the external envelope — through walls, roofs, around windows or at defective junctions. Penetrating damp is distinguished from rising damp and condensation by its location, pattern and seasonal behaviour. It is the most common source of damp in UK housing.
Purlin
A horizontal beam running along the length of a roof, supporting the rafters and transferring load to the gable walls or trusses. Purlins may be timber or steel. Rot, insect attack, deflection or inadequate bearing of purlins are significant structural defects.
Q
Quoin
The dressed or emphasised corner stones at the external angles of a building. In brick buildings, quoins may be of stone or stucco for decorative effect. Decayed stone quoins or cracked render quoins can allow water penetration at corners.
R
Rafter
A sloping timber beam forming part of the roof structure, running from the ridge to the eaves and supporting the roof covering. Rafter condition — rot, insect attack, splitting, undersizing — is one of the core assessments in any roof survey.
Rendering
An external wall finish of cement, lime or polymer-based mix applied to masonry. Render provides weather protection and an aesthetic finish. Cracking, hollow areas, debonding and inappropriate cement renders on period buildings are all survey findings.
RICS (Royal Institution of Chartered Surveyors)
The professional body governing chartered surveyors worldwide. RICS sets the standards for survey formats (Level 1, 2 and 3), valuation methodology (Red Book) and professional conduct. Choosing an RICS regulated firm ensures the survey meets independently audited standards.
RICS Level 2 Home Survey
A mid-level survey suitable for conventional properties in reasonable condition. Provides a condition rating for each element of the property using a traffic light system (condition rating 1, 2 or 3) and identifies defects requiring attention. Formerly known as the HomeBuyer Report.
RICS Level 3 Building Survey
The most comprehensive residential survey. Suitable for older properties, listed buildings, buildings of unusual construction, properties in poor repair or those being substantially altered. Provides a full description of construction, detailed defect analysis and repair recommendations.
RICS Red Book Valuation
A valuation prepared in accordance with the RICS Valuation - Global Standards. Red Book valuations are independently certified, accepted by all major lenders, HMRC, courts and regulators. Required for tax, probate, matrimonial and lending purposes where the valuation must withstand formal scrutiny.
Ridge
The horizontal apex where two roof slopes meet. Ridge tiles cap the junction and are bedded in mortar. Missing, displaced or poorly bedded ridge tiles are a common source of roof leaks.
Rising Damp
Ground moisture drawn upwards through porous masonry by capillary action, typically showing as a tide mark to about 1 metre above floor level. Rising damp requires a functioning damp proof course to prevent it. Genuine rising damp is less common than popularly believed; most damp in walls is penetrating damp or condensation.
Riser
The vertical face of a stair step. Uneven riser heights are a trip hazard and are noted in surveys. The term also refers to the vertical section of a drainage or service pipe that rises through the building.
S
Sarking
A layer of boarding or felt laid beneath the roof covering (tiles or slates) to provide a secondary barrier against water ingress. Common in Scottish construction and increasingly specified in new builds. Missing or degraded sarking felt is noted during roof inspections.
Settlement
The downward movement of a building as the ground beneath compacts under its weight, usually occurring in the early years after construction. Settlement is distinguished from subsidence — settlement is normal and self-limiting; subsidence is progressive and requires intervention.
Soffit
The underside of the roof overhang at the eaves, closing the gap between the fascia board and the wall. Soffits provide ventilation to the roof space. Rot in timber soffits, blocked ventilation slots and poorly fitted uPVC replacements are noted during surveys.
Sole Plate
The horizontal timber at the base of a timber-framed wall or partition, fixed to the floor. Rot in the sole plate where it contacts a damp solid floor is a common defect in older properties.
Spalling
The fracturing and flaking of brick or stone surfaces caused by frost action, salt crystallisation or the use of excessively hard mortar. Spalled brickwork loses its protective outer face and degrades progressively, allowing water deeper into the wall.
String Course
A horizontal projecting band of brick or stone running across a wall, typically between floors. String courses can trap water if their upper surface is not weathered (sloped), causing damp penetration into the wall below.
Stud Wall
A non-loadbearing internal partition wall of vertical timber studs faced with plasterboard or lath and plaster. Stud walls are inspected for soundness, fire separation and any concealed defects.
Subsidence
The downward movement of the ground supporting a building, typically caused by clay soil shrinkage (after prolonged dry weather or tree root activity), leaking drains softening the ground, or mining activity. Subsidence produces distinctive diagonal cracking, often wider at the top. It is a serious defect requiring structural investigation.
Surface Water Drainage
The system of pipes and gullies carrying rainwater from roofs, driveways and paved areas to a soakaway, watercourse or surface water sewer. Inadequate or blocked surface water drainage can cause localised flooding and contribute to damp at the base of walls.
Suspended Timber Floor
A ground floor of timber boards on joists, raised above the sub-floor void with ventilation through air bricks. Common in properties built before the 1970s. Inadequate sub-floor ventilation, rot in joist ends and defective damp proof courses are frequent defects.
T
Tie Bar
A metal rod, often with a decorative end plate (patress plate), inserted through a building to tie walls together where they are spreading outwards. Tie bars are common in period buildings with roof spread and in buildings where structural movement has been stabilised.
Truss
A prefabricated or site-built triangulated framework spanning the roof, supporting the roof covering and ceiling. Modern trusses are of factory-made, nail-plated softwood. Alterations to trusses — particularly cutting or notching by previous owners to create loft storage — are a serious structural defect.
Trussed Rafter
A factory-made, lightweight roof truss of thin-section timber connected by metal nail plates, introduced from the 1960s. Trussed rafters must never be cut, notched or altered on site without structural engineer approval — unauthorised alterations are one of the most frequent and serious survey findings in modern homes.
U
Underpinning
The process of strengthening and deepening the foundations of a building, typically carried out to remedy subsidence. Underpinned properties can be more difficult to mortgage and insure, and a survey should establish the date, extent and warranty position of the underpinning works.
Upstand
A vertical turn-up of waterproofing at the edge of a flat roof or at an abutment, designed to contain water and prevent it running off the edge of the roof covering. Inadequate upstand height is a common cause of flat roof leaks at perimeters.
U-Value
A measure of thermal transmittance — how much heat passes through a building element (wall, roof, floor, window). Lower U-values mean better insulation. Building Regulations set maximum U-values for new and replacement elements. Surveys note obviously inadequate insulation but do not calculate U-values.
V
Valley
The internal angle formed where two roof slopes meet, channeling water to the eaves. Valleys are lined with lead, glass fibre or proprietary valley liners. Blocked, split or poorly detailed valleys are one of the most common sources of roof leaks.
Valuation
An assessment of the market value of a property, as distinct from a survey which assesses its condition. A RICS Red Book Valuation is the highest standard of residential valuation, prepared by a RICS Registered Valuer and accepted by lenders, HMRC and courts.
Ventilation
The provision of air movement to control moisture, prevent condensation and supply combustion air. Sub-floor ventilation (air bricks), roof space ventilation (soffit and ridge vents) and room ventilation (trickle vents, extractor fans) are all assessed during surveys.
Verge
The edge of a roof at the gable end, where the roof covering meets the wall. Verge tiles or mortar bedding protect this exposed edge. Damaged or missing verge details allow water and wind uplift into the roof covering.
W
Wall Plate
A horizontal timber fixed to the top of a wall, on which the roof rafters or trusses rest and are fixed. Rot in the wall plate where it contacts damp masonry is a serious defect — the roof loses its anchorage at the eaves.
Wet Rot
Timber decay caused by fungi that require a persistently high moisture content in the wood (typically above 30%). Wet rot softens and darkens the timber and can cause structural failure if left untreated. It is distinguished from dry rot, which is more aggressive and spreads through masonry.
Woodworm
The common name for the larvae of the Common Furniture Beetle, which bore into timber, creating tunnels and exit holes. Woodworm requires treatment where active and extensive, though many infestations found in older buildings are historic and inactive.
Still have a question about a term?
If you have come across a term in your survey report that is not covered here, or you would like a more detailed explanation, our surveyors are always happy to talk through your report with you.