ABBE L6 Building Surveying cheat sheet

Defect diagnosis follows a symptom → mechanism → cause hierarchy; treating the symptom without identifying the mechanism allows recurrence.

Dampness is classified as rising, penetrating, condensation, or plumbing leak; each has a distinct moisture profile and salt pattern.

Condensation occurs when surface temperature falls below dew point; the dew point depends on air temperature and relative humidity, not on building age.

Hygroscopic salts (chlorides, nitrates) in masonry draw moisture from air at relative humidities above roughly 70–75%.

Thermal bridging raises local heat loss and lowers internal surface temperature; it is measured by linear thermal transmittance (psi value, W/mK).

Sulfate attack on cement-based mortar produces ettringite expansion; it requires a sulfate source (ground, brick, or gypsum plaster) plus moisture.

Concrete carbonation reduces pore-water pH from about 12.5 to below 9, depassivating embedded steel and initiating corrosion once the carbonation front reaches the reinforcement.

Differential movement between materials (e.g., timber and masonry) produces cracking that follows the stiffer element's geometry, often at openings and corners.

Traditional loadbearing masonry relies on mass and wall thickness for stability; modern cavity walls rely on ties, restraints, and lateral support.

Timber strength is graded (strength classes C14–C40 for softwood); moisture content above about 20% creates risk of fungal decay.

Concrete characteristic strength is defined at 28 days on 150 mm cubes (or cylinders); the specified class (e.g., C25/30) is the 5% fractile strength.

Steel loses roughly half its ambient yield strength at around 550–600 °C, which underpins fire protection thickness calculations.

Cavity wall ties should be stainless steel or equivalent; galvanized or mild steel ties corrode and cause horizontal cracking and wall tie failure.

Damp-proof courses (DPC) and damp-proof membranes (DPM) must be continuous and lapped; a bridged or discontinuous DPC defeats the whole assembly.

Cold-formed steel and engineered timber (glulam, LVL) allow long spans but require connection design and protection against moisture and fire.

Roof pitch, underlay, and ventilation must be compatible: warm and cold roof constructions have different ventilation requirements to avoid interstitial condensation.

Survey levels progress from a brief condition inspection to a full building survey; scope and limitations must be stated in the report.

Moisture meters give relative readings, not absolute moisture content; readings require calibration and corroboration with other evidence.

Thermal imaging detects temperature differences; it identifies thermal anomalies, not moisture directly, and needs confirmation with a moisture meter.

Condition assessment uses a consistent rating scale (e.g., 1–5 or A–D) applied to each element, with defect severity and urgency recorded separately.

Measured surveys use total stations, laser scanners, or photogrammetry; accuracy statements should state tolerance and datum.

A dilapidations-style schedule of condition records existing defects at lease commencement and is the baseline for later liability.

Endoscope and borescope inspection allows non-destructive examination of cavities, voids, and hidden timbers.

Sampling (e.g., for asbestos, salts, or timber decay) must follow a defined protocol; results apply only to the sampled locations.

Building Regulations approval can be obtained via full plans or building notice; completion certificates confirm compliance on completion.

The Party Wall etc. Act 1996 applies in England and Wales to party structures, excavations within 3 m (or 6 m for deeper excavation), and new walls at boundaries.

Planning permission controls use and development; listed building consent is separately required for works affecting a listed building's character.

The Construction (Design and Management) Regulations 2015 impose duties on clients, principal designers, principal contractors, and contractors, with a construction phase plan and health and safety file.

The Regulatory Reform (Fire Safety) Order 2005 places fire safety duties on the responsible person for premises; it requires a fire risk assessment.

The Control of Asbestos Regulations 2012 require asbestos surveys before work and licensed contractors for high-risk removal.

Under the Defective Premises Act 1972, a duty of care applies to work on dwellings; limitation periods differ from ordinary contract and tort periods.

Accessibility is governed by Approved Document M (and equivalent devolved documents); reasonable provision must be made for access and use.

U-values (W/m²K) measure fabric heat loss; lower values mean better insulation, and the target depends on the building element and regulations.

SAP and SBEM are the compliance tools for dwellings and non-dwellings respectively under the energy provisions of the Building Regulations.

Ventilation rates are set by Approved Document F; background ventilators plus intermittent or continuous extract must meet the specified performance.

Air permeability (m³/h·m² at 50 Pa) is measured by a pressure test; lower values indicate a tighter building envelope.

Interstitial condensation risk is assessed using the Glaser method or dynamic hygrothermal modelling; the Glaser method is steady-state and conservative.

Heat pumps, MVHR, and solar thermal must be sized against the design heat loss and hot water demand, not the boiler's nominal output.

Legionella risk management requires control of water temperatures (stored hot water above 60 °C, distribution above 50 °C, cold below 20 °C).

Acoustic performance is regulated by Approved Document E; separating wall and floor constructions must meet specified airborne and impact sound insulation.

Repair strategy selection balances cost, durability, and reversibility; like-for-like repair is generally preferred in historic fabric.

Re-pointing mortar should be weaker and more permeable than the masonry units to allow sacrificial weathering and avoid spalling.

Cement-based renders and mortars on traditional masonry can trap moisture and cause frost damage; lime-based mixes are usually more compatible.

Cathodic protection and chloride extraction are electrochemical repair options for reinforced concrete; both require specialist design.

Structural repairs (e.g., crack stitching, resin injection, underpinning) require a designed solution and monitoring, not a cosmetic patch.

Planned preventative maintenance schedules categorise work as reactive, planned, or cyclical; condition data drives the priority ranking.

Refurbishment sequencing should address structural and weathertightness works before services and finishes, with temporary works designed accordingly.

Refurbishment of buildings containing asbestos requires a refurbishment/demolition survey before works begin.

Standard forms (e.g., JCT, NEC) allocate risk differently; the choice of form and amendments determines liability and payment mechanics.

Payment provisions under the Housing Grants, Construction and Regeneration Act 1996 require a payment notice and a pay less notice within defined periods.

Variations must be instructed in writing and valued using the contract's valuation rules; oral instructions should be confirmed in writing.

Extensions of time are assessed against the contract's relevant events; a delay analysis should distinguish critical from non-critical delay.

Loss and expense claims require proof of actual loss caused by a relevant matter; they are not a penalty on the contractor.

Practical completion triggers the defects liability (or rectification) period; the defects certificate or equivalent follows at its end.

Retention is typically 5% during works, reduced to 2.5% at practical completion, released at the end of the defects period.

Programme monitoring uses critical path analysis; float ownership and its consumption affect entitlement to time and money.

Professional competence and integrity duties require disclosure of conflicts of interest and avoidance of work outside competence.

RICS and similar bodies publish ethical standards; breach can lead to disciplinary action, including expulsion.

Professional indemnity insurance covers negligent acts, errors, and omissions; it does not cover deliberate wrongdoing or contractual guarantees.

The CDM 2015 hierarchy of control requires risks to be eliminated, reduced, or controlled at source before relying on PPE.

Risk assessments must be recorded for significant risks; method statements translate assessment into safe working procedures.

Working at height, in confined spaces, and on contaminated land each require specific controls, permits, and competence checks before work starts.

Health and safety files and construction phase plans must be maintained and handed over at completion.

Confidentiality and data protection obligations apply to client information; personal data handling must comply with data protection law.

Whole-life carbon includes embodied and operational carbon; retrofit decisions should be assessed on whole-life basis, not capital cost alone.

The energy hierarchy is fabric first, then efficient services, then low-carbon supply, then renewables.

Retrofitting solid-wall buildings requires vapour-open, breathable insulation to avoid trapping moisture and causing interstitial condensation.

Historic fabric significance is assessed through statements of significance and heritage impact assessments; minimum intervention and reversibility are guiding principles.

Adaptive reuse of existing buildings usually has lower embodied carbon than demolition and new build.

BREEAM and similar schemes assess environmental performance across energy, water, materials, ecology, and management categories.

Flood resilience measures (e.g., raised services, flood barriers, permeable surfaces) should be proportionate to the assessed flood risk.

Conservation repairs should use compatible materials and traditional techniques; inappropriate modern materials can accelerate decay.

Frost damage occurs when saturated masonry freezes; it requires both high saturation and repeated freeze-thaw cycles.

Wood-boring insects (e.g., common furniture beetle) require moisture content above about 18–20% to remain active; drying the timber is part of control.

Dry rot (Serpula lacrymans) requires moisture and reduced ventilation; it can spread through masonry and behind plaster.

Corrosion of embedded steel produces expansive rust that cracks and spalls concrete cover; cover depth and concrete quality govern initiation time.

Movement cracks are classified as live or dormant; monitoring (tell-tales or gauges) distinguishes ongoing from stabilised movement.

Roof defects often present as dampness remote from the leak; water tracks along structure and emerges at the lowest point.

Defective rainwater goods cause local saturation and are a common, low-cost cause of apparently structural dampness.

Condensation risk increases with occupant moisture generation, poor ventilation, and cold surfaces; the solution addresses all three.

Masonry mortar joint thickness and bond pattern affect compressive strength and resistance to rain penetration.

Reinforced concrete cover to reinforcement protects against carbonation and chlorides; cover is specified by exposure class.

Timber frame construction requires a ventilated cavity and a breather membrane; incorrect sequencing traps moisture.

Roof underlays and sarking govern wind uplift resistance and secondary weather protection.

Thermal insulation materials differ in conductivity (lambda value); lower lambda means better insulation for a given thickness.

Movement joints in masonry accommodate thermal and moisture movement; their spacing depends on material and exposure.

Bituminous and single-ply waterproofing systems have different detailing and compatibility requirements at upstands and outlets.

Structural steel connections (bolted or welded) must be designed for the forces and protected against corrosion and fire.

A measured building survey records geometry; a condition survey records defects and their severity.

Photographic records should be dated, located, and cross-referenced to the schedule or plan.

Damp diagnosis uses a combination of visual inspection, moisture meters, and salt testing; no single test is conclusive.

Crack monitoring with tell-tales or Demec gauges records movement over time; the reading interval should match the expected rate of movement.

Non-destructive testing (e.g., cover meters, rebound hammers, ultrasonic) gives indicative results requiring calibration.

Asbestos surveys are management surveys (in-use) or refurbishment/demolition surveys (before intrusive work).

Access equipment (ladders, towers, MEWPs) selection must match the height, duration, and ground conditions of the inspection.

Reports should state the scope, limitations, and any areas not inspected, and distinguish fact from opinion.

The Building Safety Act 2022 introduces higher-risk building duties, including the golden thread of information and accountable persons.

Fire safety in higher-risk buildings requires a fire risk assessment and, where applicable, evacuation and construction control measures.

The Party Wall etc. Act 1996 requires notices, and where dissent occurs, appointment of a surveyor or surveyors to make an award.

Listed building consent is required for works affecting character; enforcement can require reinstatement.

The Equality Act 2010 requires reasonable adjustments for access to services and premises.

The Housing Act 2004 Housing Health and Safety Rating System (HHSRS) assesses hazards in dwellings, including damp and excess cold.

Contractual limitation periods and statutory limitation periods differ; the applicable period depends on the cause of action.

Building control bodies can require information and can serve enforcement notices for non-compliant work.

Thermal transmittance (U-value) is calculated from layer thicknesses and conductivities; repeating thermal bridges must be accounted for.

Overheating risk is assessed using dynamic thermal simulation or the simplified method in Approved Document O (dwellings).

Mechanical ventilation with heat recovery (MVHR) requires balanced supply and extract and regular filter maintenance.

Boiler efficiency is rated by ErP; condensing boilers recover latent heat only when return water temperature is low enough.

Lighting power density and daylight factors are used to assess lighting performance.

Water efficiency is regulated by optional requirements (e.g., 110 litres per person per day in England).

Renewable technologies (solar PV, solar thermal, heat pumps) have output profiles that must be matched to demand.

Commissioning and building log books support the performance gap between design and as-built operation.

Repair specification should state materials, methods, workmanship standards, and acceptance criteria.

Structural strengthening options include section enlargement, fibre-reinforced polymer, and external post-tensioning.

Underpinning methods include mass concrete, mini-piled, and beam-and-pile; selection depends on ground conditions and load.

Damp-proofing repairs include injection DPC, electro-osmosis, and drainage; each has limitations and should follow diagnosis.

Timber repair uses splicing, resin repairs, or replacement; structural timber repairs require design.

Refurbishment surveys should identify hazardous materials, structural condition, and services before design freeze.

Maintenance plans should include cyclical tasks (e.g., gutter clearing, roof inspections) with defined frequencies.

Temporary works (e.g., propping, scaffolding) require design and checking before loading.

Contract documents should define scope, price, time, risk allocation, and dispute resolution.

Notices and time bars are strict; failure to give notice can extinguish entitlement.

Interim valuations should reflect work executed and materials on site, subject to the contract's measurement rules.

Claims for extension of time require contemporaneous records and a causal link to the relevant event.

Dispute resolution options include adjudication (statutory right), mediation, arbitration, and litigation.

Adjudication decisions are binding until final determination; enforcement is through the courts.

Risk registers should identify, assess, and assign mitigation actions to risks.

Change control should capture scope, cost, and time impacts before authorising variations.

Conflicts of interest should be declared and managed; where they cannot be managed, the instruction should be declined.

Professional indemnity cover should be maintained at an adequate level and for the relevant period.

Health and safety risk assessments must be suitable and sufficient; they should be reviewed when circumstances change.

The CDM 2015 requires cooperation and coordination between duty holders, with a construction phase plan before work starts.

Asbestos, silica dust, and lead paint are common hazardous substances in refurbishment; controls include survey, extraction, and PPE.

Lone working, site access, and welfare facilities must be considered in method statements.

Whistleblowing and reporting of unsafe practices are part of professional duty.

Continuing professional development maintains competence and should be recorded.

Embodied carbon can be reduced by retaining structure, using low-carbon materials, and minimising waste.

Operational carbon depends on fabric performance, services efficiency, and occupant behaviour.

Life cycle assessment (LCA) stages (A1–A5, B, C, D) structure whole-life carbon reporting.

Retrofit of solid walls with internal insulation requires hygrothermal assessment to avoid condensation and decay.

Heritage significance assessment informs the acceptability of change; the greater the significance, the greater the justification required.

Reversibility and minimum intervention reduce the risk of irreversible harm to historic fabric.

Flood risk management includes avoidance, resistance, resilience, and insurance; the hierarchy should be applied in that order.

Biodiversity net gain and ecology assessments are increasingly required for planning applications.

Foundations are selected by ground conditions and load: strip, pad, raft, or piled.

Ground investigation informs foundation design; inadequate investigation is a common cause of later settlement.

Basements require waterproofing (tanking, drained cavity, or structural) and a defined waterproofing standard.

Roof structures (trussed rafters, traditional cut, or engineered) require bracing and restraint to resist wind uplift.

Cladding systems must accommodate movement and provide weathertightness and fire performance.

Fire compartmentation relies on continuity of fire-resisting construction at junctions and service penetrations.

Acoustic separation in timber frame requires mass, isolation, and sealing of junctions.

Services penetrations through fire-resisting elements must be fire-stopped to maintain compartmentation.

Survey reports should distinguish between defects that are structural, weathertightness, or cosmetic.

Cost estimates in condition reports should be indicative and clearly labelled as such.

Access to concealed areas (roof voids, subfloors, cavities) should be recorded as inspected or not inspected.

Damp readings should be taken at consistent heights and locations to allow comparison.

Crack width should be measured, not estimated; crack width and pattern inform the diagnosis.

Monitoring of movement should record temperature and moisture conditions alongside readings.

Photographic evidence should include a scale and reference point.

Reports should recommend further investigation where the evidence is insufficient for a conclusion.

Building Regulations apply to building work, material changes of use, and certain energy efficiency improvements.

Competent person schemes allow self-certification of certain works without a building control application.

Planning conditions must be discharged; failure to do so can make development unlawful.

Conservation area consent and listed building consent are separate from planning permission.

The Party Wall etc. Act 1996 awards can deal with access, security, and compensation.

Fire safety duties include means of escape, fire detection, and compartmentation, assessed by fire risk assessment.

Health and safety law imposes duties on employers, self-employed persons, and those in control of premises.

Contractual terms cannot exclude liability for death or personal injury caused by negligence.

Fabric heat loss depends on U-values and areas; ventilation heat loss depends on air change rate and temperature difference.

Heating system sizing uses design heat loss plus a margin; oversizing reduces efficiency.

Controls (thermostats, TRVs, zoning) affect actual energy use and should match occupancy patterns.

Commissioning records and building log books support efficient operation.

Air quality and ventilation should be assessed together with energy performance.

Renewable heat incentives and metering requirements affect system design and reporting.

Water heating efficiency depends on cylinder insulation, distribution losses, and control strategy.

Overheating mitigation includes shading, ventilation, and reducing internal gains.

Repair specifications should include performance requirements and verification methods.

Repair of historic fabric should use compatible materials and traditional techniques.

Damp repair should follow diagnosis; injection DPC is not a universal solution.

Structural repairs require design, checking, and monitoring.

Refurbishment should consider temporary works, access, and phasing.

Maintenance should be planned and recorded to demonstrate compliance and support future decisions.

Repair costs should be estimated with allowances for unknowns and access.

Repair works should be inspected and signed off against the specification.

Contract selection should match the project's risk profile and procurement route.

Payment terms must comply with statutory requirements, including notices and periods.

Variations should be instructed and valued under the contract.

Delay analysis should be evidence-based and contemporaneous.

Claims require proof of loss and causation.

Completion and defects periods should be defined and administered.

Retention and bonds manage performance risk.

Programme and risk management should be integrated and reviewed regularly.

Competence should be maintained and demonstrated through CPD and records.

Conflicts of interest should be declared and managed or the instruction declined.

Professional indemnity insurance should be adequate and maintained.

Risk assessments should be suitable and sufficient and reviewed.

CDM 2015 duties require cooperation and coordination.

Hazardous substances in refurbishment require survey and controls.

Lone working and site access should be risk assessed.

Unsafe practices should be reported.

Whole-life carbon should inform retrofit and new build decisions.

The energy hierarchy is fabric first, then services, then supply, then renewables.

Retrofit of solid walls requires breathable, vapour-open insulation.

Heritage significance assessment informs acceptable change.

Minimum intervention and reversibility guide conservation repairs.

Adaptive reuse usually lowers embodied carbon.

BREEAM and similar schemes assess environmental performance.

Flood resilience should be proportionate to assessed risk.

Dampness classification guides diagnosis and repair.

Condensation depends on dew point and surface temperature.

Hygroscopic salts draw moisture at high relative humidity.

Thermal bridging lowers surface temperature and raises heat loss.

Sulfate attack requires sulfate source and moisture.

Carbonation depassivates steel and initiates corrosion.

Differential movement causes cracking at openings and corners.

Frost damage requires saturation and freeze-thaw cycles.

Loadbearing masonry relies on mass and thickness.

Timber strength is graded; moisture above 20% risks decay.

Concrete strength is defined at 28 days.

Steel loses strength at elevated temperature.

Cavity ties should be corrosion resistant.

DPC and DPM must be continuous.

Engineered timber allows long spans but needs protection.

Roof ventilation must match construction type.

Survey levels range from brief to full building survey.

Moisture meters give relative readings requiring calibration.

Thermal imaging detects temperature anomalies, not moisture directly.

Condition ratings should be consistent and recorded per element.

Measured surveys should state tolerance and datum.

Schedules of condition record baseline defects.

Endoscopes allow non-destructive inspection of cavities.

Sampling results apply only to sampled locations.

Building Regulations approval routes are full plans or building notice.

The Party Wall etc. Act 1996 covers party structures, excavations, and boundary walls.

Planning permission and listed building consent are separate.

CDM 2015 imposes duties on clients, designers, and contractors.

The Regulatory Reform (Fire Safety) Order 2005 requires a fire risk assessment.

Asbestos regulations require surveys before work.

The Defective Premises Act 1972 imposes a duty of care for dwellings.

Approved Document M governs accessibility.

U-values measure fabric heat loss.

SAP and SBEM are compliance tools.

Approved Document F sets ventilation rates.

Air permeability is measured by pressure test.

Glaser method assesses interstitial condensation.

Heat pumps and MVHR must be sized to demand.

Legionella control requires temperature control.

Approved Document E regulates acoustic performance.

Repair strategy balances cost, durability, and reversibility.

Re-pointing mortar should be weaker than the masonry.

Lime-based mixes are more compatible with traditional masonry.

Electrochemical repair options require specialist design.

Structural repairs require design and monitoring.

Maintenance is reactive, planned, or cyclical.

Refurbishment sequencing addresses structure and weathertightness first.

Asbestos refurbishment surveys are required before works.

Standard forms allocate risk differently.

Payment notices and pay less notices are statutory requirements.

Variations must be instructed in writing.

Extensions of time are assessed against relevant events.

Loss and expense requires proof of loss.

Practical completion triggers the defects period.

Retention is typically 5% reduced to 2.5%.

Critical path analysis informs delay entitlement.

Conflicts of interest must be disclosed and managed.

Professional bodies publish ethical standards.

Professional indemnity insurance covers negligent acts.

CDM 2015 requires risk elimination first.

Risk assessments must be recorded for significant risks.

Work at height and confined spaces require specific controls.

Health and safety files must be handed over.

Data protection applies to client information.

Whole-life carbon includes embodied and operational carbon.

Energy hierarchy is fabric first.

Solid-wall retrofit requires vapour-open insulation.

Significance assessment informs heritage impact.

Minimum intervention and reversibility guide conservation.

Adaptive reuse lowers embodied carbon.

BREEAM assesses environmental performance.

Flood resilience should be proportionate to risk.