I’ve been covering workplace trends and operational risks for years, and one thing that keeps coming up is indoor air quality (IAQ). It’s no longer a niche health concern — it’s a business issue that affects productivity, sick days, employee retention, and even brand reputation. If you haven’t audited the air in your office, workshop, or retail space recently (or ever), now is the moment to act. Below I’ll explain why an IAQ audit matters and give a practical, step-by-step way to carry one out for under £500.

Why run an air quality audit now?

There are three simple reasons I think every business should prioritise an IAQ audit:

  • People performance: Poor air — elevated CO2, volatile organic compounds (VOCs), or particulate matter — reduces concentration, increases headaches and fatigue, and leads to lower productivity. Improving air quality is a low-tech way to boost output.
  • Health and absence management: Better ventilation and cleaner air reduce the spread of respiratory infections and cut sickness absence. That can translate into tangible savings.
  • Risk and compliance: Regulators and stakeholders are paying attention. An audit demonstrates due diligence, which matters for insurers, clients, and employees who expect safe workplaces.

    • Beyond these, IAQ has become a visible part of employer branding. I’ve heard from candidates who check a company’s approach to workplace safety and wellbeing before accepting offers. An audit shows you care.

    What does an air quality audit actually measure?

    An easily executed audit looks at the key measurable factors that affect air safety and comfort:

  • CO2 levels — a proxy for how well-ventilated a space is. High CO2 (above ~1000 ppm) indicates the air is stale and ventilation needs improvement.
  • Particulate matter (PM2.5 and PM10) — tiny particles from outdoor pollution, cooking, or office activities that can aggravate respiratory conditions.
  • Volatile organic compounds (VOCs) — emitted from cleaning products, paints, furniture and some office equipment; they affect comfort and can have health implications.
  • Temperature and humidity — important for comfort and for controlling mould and viral persistence.

    • You don’t need laboratory-grade testing to get actionable data — reliable consumer and prosumer monitors can give you the information you need to prioritise fixes.

    How to run a practical audit under £500

    I designed the following approach so a small facilities team or even an office manager can implement it without specialist training. The total cost is deliberately conservative and focused on buying a few good sensors and following a robust sampling plan.

    Step 1 — Define your scope

    Decide which spaces you will test. I usually recommend starting with:

  • Open-plan office areas where most people work
  • Meeting rooms and hot-desking spaces
  • Reception, kitchens, and breakout areas
  • Any enclosed or poorly ventilated rooms (server rooms, storage)

    • For most small-to-medium offices, testing 4–8 locations gives a representative view.

    Step 2 — Buy the right equipment (what to spend £ on)

    Under £500 you can buy a combination of CO2, PM, and multi-parameter monitors that will provide actionable readings. Here are device types and example brands I’ve tried or tested in reporting:

  • CO2 monitor: Look for NDIR sensors (more accurate than electrochemical). Recommended models: Aranet4 (often >£200), CO2Meter devices, or the TemTop M2000. Budget CO2 monitors (around £80–£150) from brands like CO2Meter or some Amazon basics are fine for screening.
  • Particulate/VOC monitor: PurpleAir (outdoor/indoor) and Airthings Wave Plus are popular — Airthings gives VOC and radon options; PurpleAir excels at PM2.5. A single portable PM/VOC monitor (e.g., Temtop LKC-1000S+, Awair Element, or Xiaomi Mi Air Quality Monitor) costs ~£100–£200.
  • Combination units: Devices like the Airthings Wave Plus or the Foobot measure multiple parameters and offer smartphone apps. These can reduce total device count.

    • Example budget breakdown (representative):

    Item Typical cost (GBP)
    CO2 monitor (portable NDIR) £80–£200
    PM2.5 / VOC monitor £80–£200
    Spare sensors / batteries / stands £20–£50
    Estimated total £180–£450

    Pick one CO2 monitor and one PM/VOC unit for a small office, or two CO2 units if you want to focus on ventilation initially.

    Step 3 — Plan the sampling

    Good sampling means measuring at representative times and positions. I would:

  • Place monitors at breathing height (~1.1–1.7 metres) away from windows and HVAC vents to avoid skewed readings.
  • Run measurements during peak occupancy (e.g., mid-morning and mid-afternoon) and during low-occupancy periods for contrast.
  • Record each location for at least 1–2 hours per session for CO2. PM/VOC can be spot-checked for shorter snapshots but repeat across days where possible.
  • Take notes on room use, number of occupants, whether windows/doors were open, and HVAC settings.

    • Step 4 — Interpret the data (what’s actionable)

    Here’s a practical threshold guide I use when reviewing results:

  • CO2 under 800 ppm: Good — ventilation is generally adequate.
  • CO2 800–1000 ppm: Acceptable but could be improved during peak times.
  • CO2 above 1000 ppm: Action needed — increase ventilation or reduce occupancy.
  • PM2.5: Aim for <25 µg/m3 (24-hour average). Spikes above this indicate pollution sources that should be addressed.
  • VOCs: There's no single standard, but sustained high readings after cleaning or renovations suggest source control or product changes are needed.

    • When I analyse results, I focus on patterns — repeated CO2 peaks in a meeting room, regular PM spikes near a kitchen, or VOC elevations after cleaning. Those point to specific interventions.

    Step 5 — Take inexpensive, high-impact actions

    Many fixes are cheap and quick:

  • Increase natural ventilation: Open windows or stagger windows/doors to create cross-breezes.
  • Adjust ventilation schedules: Set HVAC systems to run more fresh air around peak times; even increasing airflow by 10–20% helps.
  • Control sources: Switch cleaning products, reduce strong-scented aerosols, and ensure printers are in ventilated spaces.
  • Use portable air cleaners: HEPA air purifiers for meeting rooms or kitchens can be bought for £100–£300 and target PM and some VOCs.
  • Occupancy management: Limit the number of people in small rooms or schedule shorter meetings.

    • I’ve seen offices fix persistent CO2 issues simply by cracking windows and changing meeting-room booking rules. Small behaviour and scheduling changes often produce the biggest, cheapest gains.

    Step 6 — Report and monitor

    Turn your findings into a simple one-page report for leadership and staff: show the highs and lows, the likely causes, and recommended actions with estimated costs. Transparency builds trust — share CO2 logs for meeting rooms and put clear signage or a live display in breakout areas if you can.

    Finally, keep the monitors in rotation. I recommend a re-check after you implement fixes (2–4 weeks), then quarterly spot-checks. Continuous monitoring in high-use rooms is worth the extra spend if staff health is a priority.

    Running an air quality audit is not an academic exercise — it’s a practical way to protect people and performance. With under £500 and a few hours of work, you can map the biggest problem areas and take steps that employees will notice and appreciate.