HTM 03-01 (Health Technical Memorandum 03-01) is the Department of Health and Social Care's guidance on specialised ventilation for healthcare premises in the UK. It covers design, validation, verification and ongoing operation of ventilation in NHS and private healthcare buildings.

Is HTM 03-01 mandatory?

HTM 03-01 is guidance, not statute — but NHS estates contracts, CQC inspection expectations and BS EN building regulations effectively require compliance. Deviation must be risk-assessed and documented.

How often must HTM 03-01 ventilation be verified?

Critical ventilation systems (operating theatres, isolation rooms, pharmacy clean rooms) require annual verification by a competent person, with quarterly checks on key parameters and continuous monitoring of pressure regimes.

HTM 03-01: NHS Healthcare Ventilation Standard Explained (UK)

What HTM 03-01 covers

HTM 03-01 — Specialised ventilation for healthcare premises — applies to all UK healthcare buildings where ventilation is critical to infection control, contaminant containment or patient safety. It supersedes earlier HTM 2025 guidance and is referenced across NHS estates contracts.

The memorandum is split into two parts: Part A: Design and Validation (specification, commissioning, verification) and Part B: Operational Management (planned preventive maintenance, performance monitoring, recommissioning).

Room categories and air change rates

HTM 03-01 prescribes minimum ventilation provisions by clinical area:

Conventional operating theatre: 25 ac/h, positive pressure relative to corridor
Ultraclean ventilation (UCV) theatre: laminar flow canopy, >65 ac/h equivalent
Source isolation room (negative pressure): 10 ac/h, lobby with pressure cascade
Protective isolation room (positive pressure): 10 ac/h, HEPA-filtered supply
General ward areas: 6 ac/h or equivalent natural ventilation
Pharmacy aseptic suite: ISO Class 5–8 zoned environment

Pressure regimes

Differential pressure between rooms is the primary infection-control mechanism. HTM 03-01 specifies measurable cascades — typically ±10 to ±15 Pa — with permanent gauges visible from the corridor and continuous monitoring in critical areas. Loss of pressure must trigger alarm protocols.

Validation and verification

HTM 03-01 distinguishes validation (initial commissioning to design intent) from verification (ongoing demonstration of continued performance). The Authorised Person (Ventilation) and Competent Person (Ventilation) roles are formally defined.

Critical ventilation requires annual verification with documented evidence of air change rates, filter integrity, pressure differentials and microbiological monitoring where applicable. Findings feed into the estates risk register.

Defined roles

Designated Person (DP): board-level accountability
Authorised Person (AP): day-to-day management of ventilation systems
Competent Person (CP): specialist verification engineer
Authorising Engineer (AE): independent professional advisor

HTM 03-01: Ventilation for UK Healthcare Premises

What HTM 03-01 covers

Room categories and air change rates

Pressure regimes

Validation and verification

Defined roles

HTM 03-01 verification for your healthcare estate

HTM 03-01: Ventilation for UK Healthcare Premises

What HTM 03-01 covers

Room categories and air change rates

Pressure regimes

Validation and verification

Defined roles

How HTM 03-01 fits the UK regulatory stack

HTM 03-01 verification for your healthcare estate