A Complete Guide to Ventilation Compliance in Scotland: DW172 & TR19 for Commercial Kitchens

Ensuring compliant ventilation in Scotland isn’t just about improving air quality: it’s about meeting essential industry and safety standards that protect people, property and the continuity of your business. 

At Sigma Engineering, we design, manufacture, and install commercial ventilation systems across Scotland. We’ve helped businesses in sectors from hospitality to healthcare invest in compliant, efficient systems that meet or exceed relevant standards such as DW/172 and TR19.

In this guide, we’ll explain what these standards are, why they matter for commercial kitchens and other occupational spaces in Scotland, and how our bespoke approach ensures compliance while achieving performance and energy efficiency goals.

What Are DW/172 and TR19?

To put it simply, DW/172 defines how kitchen extract systems should be designed and installed; TR19 guides how they must be maintained and cleaned to stay safe and compliant over time.

DW/172 is the Specification for Kitchen Ventilation Systems published by the Building Engineering Services Association (BESA), and it has become the authoritative standard in the UK for designing, installing and maintaining commercial kitchen ventilation. It’s widely referenced by designers, contractors and building control professionals because it defines best practice for canopy design, airflow rates, grease management, fire safety and more.

While DW/172 isn’t legislation in itself, adherence to it is generally expected where commercial kitchen systems are installed. 

TR19, on the other hand, is the HVCA (Heating and Ventilating Contractors’ Association) Guide to Good Practice for commercial kitchen extract systems. It focuses on internal cleanliness, accessibility for cleaning, and maintenance procedures that prevent the build-up of grease and contaminants inside ductwork and fans — a significant fire hazard if ignored.

Why Compliance Matters for Ventilation

Ventilation is a vital part of health and safety in a commercial kitchen. Simply put, it protects people and premises from a range of risks:

Health and Safety

Commercial kitchens generate heat, steam, odours, smoke, and airborne contaminants (unspent gasses) that must be removed efficiently. Without effective ventilation, staff in a kitchen may be exposed to conditions that compromise their comfort and health. 

Proper ventilation also removes combustion by-products from gas appliances, improving safety and working conditions.

Preventing Fires

Grease accumulation in ductwork and extract canopies is one of the most common causes of kitchen fires. DW/172 outlines design strategies — such as canopy sizing and access for cleaning — that reduce the likelihood of grease build-up, while TR19 ensures that maintenance regimes keep internal system surfaces free of risk.

Regulatory and Insurance Compliance

Building control officers, insurers, and environmental health inspectors often reference DW/172 and TR19 when assessing compliance. Systems that are well-designed and maintained under these standards are easier to justify during audits or inspections, and they help protect businesses from fines, enforcement notices or insurance issues.

Energy Efficiency and Operational Performance

Poorly designed ventilation systems can waste energy, drive up utility bills, and struggle to maintain balanced airflow. By designing systems with correct extraction rates, make-up air integration, and modern fan technology, compliance can also deliver better performance and lower on-going costs.

How Sigma Engineering Ensures DW172 & TR19 Compliance

At Sigma Engineering, we take a holistic approach to ventilation compliance that combines industry expertise with tailored engineering solutions.

Bespoke System Design

Kitchens vary a great deal in layout, cooking processes, and extract requirements. We begin every project with a detailed survey to understand your operational needs, layout constraints and performance goals.

Using this insight, we design bespoke extract canopies, duct systems, fans, and make-up air solutions that are sized and specified to meet DW/172 standards for airflow, canopy coverage, fire rating and access for cleaning — all critical for compliance from day one.

Advanced Technology & Components

We incorporate high-efficiency fans, energy recovery elements, and precision-engineered ductwork into our systems to achieve efficient performance without compromising compliance.

Maintenance Accessibility

DW/172 and TR19 both emphasise the importance of accessible internal surfaces for cleaning. We integrate ample access panels and design system layouts that make regular cleaning straightforward. This reduces the risk of grease build-up and ensures that maintenance teams can meet the rigorous cleaning standards set out in TR19.

Consulting and Documentation

Regulatory compliance often depends on good documentation. As a registered member of BESA, we prepare accredited planning designs, technical drawings and compliance documentation that give confidence to building control officers, planners, and insurers alike.

Common Sectors That Benefit from Compliance

We support clients across a range of sectors where effective ventilation is critical:

• Commercial Kitchens and Restaurants – from casual dining venues to large hospitality operations, where the performance of the extraction system is paramount.

• Healthcare and Care Homes – where air quality affects vulnerable occupants.

• Industrial and Manufacturing Facilities – controlling fumes, dust and process emissions with Local Exhaust Ventilation (LEV) systems.

• Public Buildings and Education – ensuring healthy environments for students and staff.

  
  

Staying Compliant Over Time

Unfortunately, compliance isn’t just a one-off project: it’s an ongoing commitment. At Sigma Engineering, we can assist with maintenance planning and advice, even if we didn’t originally install your system, to help you maintain cleanliness, airflow balance, and performance.