The WELL Building Standard, a certification mark of the International WELL Building Institute, uses on-site performance testing to obtain physical evidence across five concepts: Air, Water, Light, Thermal Comfort and Sound. The measurements are not interchangeable. Each concept concerns a different physical quantity, evidence form and part of the occupied environment, so the testing programme must map the relevant spaces and systems to the correct form of verification.
A measurement map helps project teams understand what the on-site visit is intended to produce without turning the overview into a testing manual. It identifies the concept, the physical quantity or sample collected and the type of result that enters the performance-verification record.
The map is useful because full certification combines several kinds of evidence. Some results are read directly from instruments at the building, while others depend on samples collected on site and analysed by a laboratory. The route used depends on the quantity being assessed and the scheme's current verification requirements.
The five measured concepts do not represent the whole standard. Other requirements are demonstrated through documents, policies, drawings, schedules, photographs or other accepted evidence. On-site testing is the physical-performance part of a broader review rather than a complete assessment of every feature.
The scheme owner's current performance-verification guidance identifies Air, Water, Light, Thermal Comfort and Sound as the concepts from which the testing agent collects real-world environmental data.
Air testing measures concentrations of specified airborne pollutants in the occupied environment. The result for each parameter is a concentration associated with the tested location and the conditions required by the scheme. This page does not state the applicable limits, which are presented only on the separate air-quality performance-testing page.
Some air parameters are measured with direct-reading instruments at the site. These instruments produce readings during the testing period and allow the Performance Testing Agent to compile location-specific results without waiting for an external laboratory report.
Other air parameters are assessed through samples collected in the building and sent for laboratory analysis. The resulting laboratory data becomes part of the submitted performance evidence. Direct readings and laboratory-analysed samples therefore sit within the same concept but produce different forms of record.
This overview does not address pollutant chemistry, health effects, formation or detailed sampling methodology. Those subjects belong to separate technical resources, while the scheme page is limited to identifying that airborne pollutant concentration is the physical quantity being verified.
Water testing concerns the quality of drinking water available within the project. Samples are collected at relevant outlets or points of provision within the site so that the result relates to the water occupants can access in the completed facility.
The samples are sent to a third-party laboratory for analysis. The laboratory report provides the measured values for the specified water-quality parameters and becomes part of the performance-verification submission.
The physical quantity is therefore the concentration or level of the relevant constituent in the collected drinking-water sample. The site visit establishes where and how the project's drinking water is represented, while the laboratory produces the analytical result.
The map does not extend into water-treatment design, plumbing hygiene or the causes of a particular result. It simply identifies on-site collection followed by third-party laboratory analysis as the evidence route used for drinking-water measurements.
Light testing measures illuminance in lux at the locations required by the performance-verification plan. Illuminance is the quantity recorded for the tested point or area, allowing the submission to show the level of light present under the conditions specified for the assessment.
The result is produced through on-site measurement in the completed space. It is not inferred solely from luminaire schedules, design calculations or visual inspection, even though those documents may remain relevant elsewhere in the project evidence.
This page does not explain how a light meter operates, how a measurement grid is established or how daylight and electric lighting are separated in a detailed assessment. Its purpose is limited to naming illuminance, expressed in lux, as the physical quantity measured under the Light concept.
Facilities teams need to recognise that the measurement reflects the tested operational state. Access to lighting controls and the ability to place the space in the condition required by the scheme are therefore practical parts of preparing for the visit, without changing the quantity being measured.
Thermal Comfort testing records dry-bulb air temperature together with relative humidity. These are separate physical quantities collected at the relevant testing locations and reported as part of the thermal performance evidence.
Dry-bulb air temperature is expressed as a temperature reading, while relative humidity is expressed as a proportion of moisture relative to the air's capacity under the measured condition. The scheme uses the paired results to document the thermal environment present at the time and place of testing.
The map does not explain thermal-comfort modelling, personal preference, heat transfer or humidity-control practice. It identifies only the two quantities obtained on site: dry-bulb air temperature and relative humidity.
Because both values can vary across a building, the testing plan links readings to selected locations rather than treating one plant-room setting or control-panel value as a complete description of occupied conditions.
Sound testing measures sound pressure level in decibels using a sound level meter. The result records the acoustic level present at the tested location under the conditions required for the relevant feature.
The on-site measurement is distinct from an acoustic design prediction or a product specification. Design documents can describe intended performance, while the sound level meter records the condition encountered in the completed space.
The Sound concept may involve different testing circumstances depending on the feature being pursued, but the core physical quantity named in this map is sound pressure level expressed in decibels. Detailed acoustic methodology, frequency treatment and instrument settings are outside the scope of this page.
Preparation may require coordination of occupancy and building systems so that the intended condition can be assessed. The scheme owner's site-preparation guidance identifies Sound as one of the concepts requiring specific operational attention during the testing visit.
The five concepts generate a mixed evidence package. Air can include direct readings and laboratory results. Water relies on samples collected on site and analysed by a third-party laboratory. Light provides illuminance readings in lux. Thermal Comfort provides dry-bulb air temperature and relative humidity. Sound provides sound pressure level in decibels from a sound level meter.
The Performance Testing Agent organises these outputs so they can be linked to the correct locations, features and project documents. The separate WELL Reviewer then assesses the submitted performance evidence within the wider review process.
The measurement map should not be used as a substitute for the current performance-verification guide. It names the quantities but does not reproduce sampling locations, durations, equipment specifications, acceptance limits or detailed procedures.
The neighbouring pages explain the two annual ratings, the two-stage verification process and the air-quality thresholds without repeating those subjects here.
This website is an independent explanatory resource with no affiliation, endorsement, accreditation, partnership, assessor, provider or agency status under the scheme. It does not conduct testing, collect scheme samples, review data or determine whether a project achieves a feature.
The scheme's protected manuals and technical procedures are summarised rather than reproduced. Project teams should use current material issued by International WELL Building Institute pbc and the appointed testing provider when planning the actual visit.
The page also intentionally excludes pollutant chemistry, health effects, formation, toxicology, detailed sampling methods, light-meter operation, mould, ventilation hygiene and duct cleaning. Those subjects require separate treatment and should not be inferred from this high-level map.
An independent resource. WELL is a certification mark of the International WELL Building Institute pbc. No affiliation, endorsement or accreditation.
The on-site performance-testing programme spans Air, Water, Light, Thermal Comfort and Sound. These five concepts generate physical measurement or sample evidence for the performance-verification process.
Specified airborne pollutant concentrations are measured. Some results come from direct-reading instruments, while other parameters use samples collected on site and analysed by a laboratory.
Drinking-water samples are collected at the site and sent to a third-party laboratory. The laboratory results form part of the submitted Water performance evidence.
Illuminance is measured in lux. The page does not describe the operation of the measuring instrument or the detailed testing procedure.
Thermal Comfort records dry-bulb air temperature together with relative humidity. Sound records sound pressure level in decibels using a sound level meter.
No. It is a map of measured concepts and physical quantities. Air-quality limits appear only on the neighbouring air-quality performance-testing page, while other limits remain in the current scheme material.
This site is an independent information resource. It is not affiliated with, endorsed by, accredited by or authorised by the International WELL Building Institute pbc, which owns the WELL certification mark, and it is not a certification body, an assessor, a performance testing provider or a scheme partner. Nothing on this page can certify, assess or award anything under the scheme, and nothing here is a substitute for the scheme's own published documentation. Requirements are summarised factually rather than reproduced; where a numeric threshold is stated it is drawn from documentation the scheme's owner publishes openly, and the specific figure is cited rather than the table it sits in. Certification under the scheme is voluntary and is not required by any authority in the United Arab Emirates.