Healthy indoor environments

Monitoring for healthy indoor environments

A healthy indoor environment is the combination of clean air, adequate fresh-air supply and stable thermal conditions — measured continuously and benchmarked against recognised references. Monitoring turns 'the building feels stuffy' into an objective record building managers and occupiers can act on.

CO₂612 ppmPM2.58 µg/m³VOC0.21 mg/m³RH46 %

What a healthy indoor environment measures

The parameter set behind a healthy building

No single number defines a healthy indoor environment. The combination of pollutants, ventilation and comfort parameters is what matters — and what monitoring captures.

CO₂

Ventilation

Proxy for fresh-air supply per occupant.

PM2.5

Particles

Outdoor ingress and indoor activity.

TVOC / HCHO

Chemistry

Materials, furnishings, cleaning products.

T / RH

Comfort

Thermal comfort drives perceived air quality.

Continuous baseline

Calibrated sensors record CO₂, particulates, temperature and humidity through real occupancy patterns — not a single spot reading.

Periodic deep dive

Periodic laboratory testing for VOCs and formaldehyde adds chemistry the continuous sensors cannot resolve.

Ventilation tuning

Measured CO₂ and fresh-air data identify when systems run too lean or too hard, supporting setpoint and schedule changes.

Reporting & dashboards

Trends, exceedance summaries and benchmarked reports for facilities, ESG and wellbeing reporting cycles.

When to invest

Typical healthy-building monitoring scenarios

Workplaces pursuing WELL or Fitwel; landlords differentiating on indoor environmental quality; schools and healthcare estates with sensitive occupants; ESG and wellbeing reporting that needs measured rather than asserted IAQ performance.

Combine with BREEAM indoor air quality support, UK IAQ regulations guidance and office ventilation monitoring.

Benchmarks

Reference frameworks for healthy indoor environments

ParameterTypical referenceSource
CO₂< ~800 ppm above outdoorBS EN 16798-1 Cat II
PM2.5 (24-h)< 15 µg/m³WHO 2021
TVOC< 500 µg/m³WELL v2 Air
Formaldehyde (30-min)< 100 µg/m³WHO IAQ guideline
Operative temperature20–24 °C (winter) / 23–26 °C (summer)CIBSE Guide A
Relative humidity40–60 %ASHRAE 55 / WELL v2

Build a healthy indoor environment programme

Continuous monitoring and periodic testing, benchmarked against the standards that matter for your asset and occupants.

Request a healthy-building proposal