The 2024 update to AS 1668.2 changes how some cooking equipment is classified, how hoods are sized, and when exhaust is required. These changes may affect compliance, exhaust rates, kitchen layouts and upgrade costs for buildings with commercial kitchens.
If you own, operate, design, lease or refurbish buildings with commercial kitchens, we recommend getting up to speed with these changes. This update is particularly relevant if you’re planning a new commercial kitchen, upgrading an existing one, changing cooking equipment or preparing a tenancy for food retailer.
Summary of the 2024 update to AS 1668.2
The 2024 update to AS 1668.2 introduces important changes to the way commercial kitchen ventilation is assessed and designed. While some of the underlying exhaust-rate methods remain broadly consistent with the 2012 standard, the way cooking processes are classified has changed:
- Some equipment now sits in a different process type.
- A new process type has been introduced for solid fuel equipment.
- Minimum hood overhang requirements have been revised.
Why you need to be across the 2024 update to AS 1668.2
‘For building owners, operators and project teams, this means a kitchen design that appeared compliant under the 2012 standard may need to be recalculated under the 2024 version.’
In some cases, this could increase the required exhaust rate, change the size or suitability of the canopy or trigger the need for local exhaust where it was not previously required.
These changes matter because commercial kitchen ventilation affects safety, compliance, odour control, heat management, tenancy flexibility, energy use and the ability to secure approvals without late redesign.
Understand if the changes impact your kitchen
This article does not attempt to reproduce the standard. Instead, we aim to explain the practical changes project teams should be aware of when planning, designing or upgrading commercial kitchen.
Here’s our step-by-step guide to knowing if these changes impact your commercial kitchen.
1. Check whether your equipment classification has changed.
Some appliances have moved into different process types under the 2024 standard. For example, several steam-producing or grease-producing appliances are now more clearly classified, including pasta and noodle cookers, stock pots, dim sum steamers and pressure cookers.
2. Check whether your hood size still works.
Some hood overhang requirements have increased. For example, Type 1 and Type 4 process hoods now require 300 mm front and side overhangs, compared with 150 mm under the 2012 standard.
3. Check whether exhaust is now required.
Some equipment that may previously have been treated as low risk can now require local exhaust depending on input, separation distance and grouping with other equipment.
What happens if I do nothing?
Failure to apply the 2024 requirements early can lead to late-stage redesign. If equipment is reclassified, or if the hood overhang or exhaust rate changes, the impact may flow through to ductwork, fan selection, roof penetrations, make-up air, ceiling coordination, fire safety interfaces, acoustic treatment and available kitchen space.
In practical terms, not applying the changes may lead to:
- non-compliant kitchen ventilation design
- undersized or unsuitable exhaust hoods
- insufficient exhaust flow rates
- increased heat, grease, vapour, smoke or odour issues
- approval delays
- redesign during documentation or construction
- higher retrofit costs
- reduced tenancy flexibility
- increased operational and maintenance issues.
What the technical changes mean in practice
These tables are a guide. We recommend still engaging a consultant to assess your final kitchen design against the full standard.
Process type reclassification
The 2024 standard keeps the broad exhaust-rate method but changes the way some cooking processes are described and classified. This matters because the process type influences hood selection, hood size and the exhaust rate that needs to be calculated.
| Process type | 2012 standard | 2024 standard | What this means in practice |
|---|---|---|---|
| 1 | Non-grease-producing equipment and void spaces under the hood | No grease; non-greasy heat or steam only Examples include dishwashers, warming cabinets, sous vide cookers, urns and rice cookers. | Confirm the equipment genuinely produces no grease before assuming a lower exhaust requirement or smaller hood arrangement. |
| 2 | Low-grease, medium-heat equipment such as griddles, ranges, salamanders, conventional fryers and induction cookers | Grease with moderate heat and little steam Examples include induction cooktops, skillets/fryers, fry tops, ranges and salamanders. | Check the actual appliance duty rather than relying on a generic equipment list. |
| 3 | High-grease, low-heat equipment such as electric deep-fat fryers, grooved griddles, hot tops and hot top ranges | Steam and grease Examples include tilting steam kettles, stock pots, pasta/noodle cookers, yum cha, dim sum steamers and pressure cookers. | A key change for steam-producing equipment. Some appliances may need revised exhaust calculations and canopy checks. |
| 4 | High-grease, medium-heat equipment such as countertop barbecues and gas-fired deep fat fryers | High grease Examples include deep fryers, bratt pans, induction woks and high-energy burger fry tops. | May require more robust capture and filtration, affecting hood size, exhaust rates, ductwork and maintenance access. |
| 5 | High-grease, high-heat equipment and open flame charcoal equipment using solid fuel | High heat, with or without grease Examples include char grills, lava rock grills, broilers, BBQs, tandoor ovens and open flame apparatus. | Identify high-heat cooking early because it can affect hood suitability, make-up air, heat load and fire safety interfaces. |
| 6 | Oriental cooking tables and woks | Very high grease, heat and vapour, including woks and oriental cooking tables | Usually needs close coordination of exhaust, make-up air, fire protection, acoustics and space planning. |
| 7 | Bread ovens and steam-producing combination ovens | Large surges of contaminants, including full-height and multistack ovens and steam-producing combination ovens | Consider peak operation and surge loads, not just the normal operating condition. |
| 8 | Not applicable | Smoke and embers from solid fuel apparatus, including open flame grills and enclosed ovens that burn charcoal or wood | Solid fuel cooking needs early review of smoke, embers, spark arresting, fire risk, exhaust discharge and approvals. |
Note: warming cabinets used only for holding or reheating may be excluded from Type B local exhaust requirements and may not require a canopy. This should still be confirmed against the final equipment selection and use.
| Cooking equipment | 2012 classification | 2024 classification | What this means in practice |
|---|---|---|---|
| Steam or tilting kettles | 2 | 3 | Review exhaust rates and hood capture for steam-and-grease loads |
| Pressure cookers | 2 | 3 | Assess carefully, particularly where several appliances operate together |
| Dim sum steamers | 2 | 3 | Allow for steam and grease; previous lower-risk assumptions may no longer apply |
| Pasta/noodle cookers | 1 | 3 | Substantial shift, a different exhaust approach may now be needed |
| Stock pots | 2 | 3 | Recalculate hood performance and exhaust rates for steam and grease |
| Yum cha equipment | 2 | 3 | May affect hood sizing and exhaust in Asian food tenancies and food courts |
| Hot top ranges | 3 | 2 | May move to a lower classification but verify against actual use |
| Electric deep fat fryers | 3 | 4 | Higher grease classification, check grease capture, filtration, cleaning access and exhaust flow |
| All solid fuel apparatus | 5 | 8 | Treat as a distinct design and compliance risk, not a standard high-heat process |
Note: pressure cookers, dim sum steamers, pasta/noodle cookers, stock pots and yum cha are explicitly nominated as Process Type 3 equipment in the 2024 standard.
| Cooking process type | 2012 hood size requirement | 2024 hood size requirement | What this means in practice |
|---|---|---|---|
| 1 | 150 mm front and side overhang | 300 mm front and side overhang | Some hoods may need to be larger, affecting kitchen layout, ceiling coordination and available space. |
| 4 | 150 mm front and side overhang | 300 mm front and side overhang | Higher-grease equipment may need a larger capture area. Compact kitchens may need redesign or equipment relocation. |
| 7 | 450 mm front and side overhang | 450 mm front and 300 mm side overhang | The side overhang may reduce in some cases, but the final equipment and hood layout still need to be checked. |
| 8 | Not applicable | 300 mm from ember escape openings Additional requirements apply for oven doors used as cooking surfaces or low apparatus openings. | Solid fuel hoods need early spatial coordination for door swings, ember escape points, equipment height and fire safety interfaces. |
A typical exhaust hood for a Type 1 or Type 4 process may require an increased exhaust flow rate, while a typical Type 7 hood exhaust rate may reduce. The final outcome depends on the equipment selection, hood geometry and operating profile, so exhaust rates should be recalculated rather than carried over from previous designs.
| Requirement | What’s changed | What this means in practice |
|---|---|---|
| Type 1 cooking process hoods | Maximum horizontal setback from the leading edge of the apparatus is now 150 mm, previously 300 mm | There’s less tolerance for setting equipment back from the hood edge. Existing layouts may need adjustment. |
| Microwave ovens, under-bench ovens and dish or glass washers | May require an exhaust hood if maximum input exceeds 3.6 kW and equipment is positioned less than 1.5 m apart | Minor equipment can trigger exhaust requirements when grouped – check tenancy layouts before installation. |
| Individual deep fryers below 3.6 kW | May not require an exhaust hood if not within 2 m of other cooking equipment | Some small appliances may have a simpler pathway, but only where separation and input limits are satisfied. |
| Multiple process type 3-6 appliances | Where appliances are within 2 m and total maximum input exceeds 3.6 kW, Type B local exhaust applies | Assess the whole cooking line, not each appliance separately. |
| Low sidewall hoods | No longer suitable for Type 5 cooking processes | Existing hood types may not remain suitable where high-heat cooking is proposed. |
What the standards update means for existing kitchens
For existing buildings, the 2024 update is most likely to matter when a kitchen is being altered, a tenancy is changing, equipment is being replaced or food production is increasing. The change may not require every operating kitchen to be redesigned immediately but it does mean previous assumptions should not be reused without checking them.
Actions for existing building owners and managers
- Review the actual equipment list, not just the existing canopy. A change from one appliance type to another can shift the process classification and affect exhaust requirements.
- Check whether the existing hood still provides the required overhang, particularly for Type 1 and Type 4 processes where the minimum front and side overhang has increased.
- Recalculate exhaust rates before committing to a tenant fitout or equipment upgrade. A higher exhaust requirement can affect fans, ducts, make-up air, roof penetrations, electrical loads and acoustics.
- Look at equipment grouping and separation distances. Several smaller appliances close together may trigger local exhaust even if each item seems low risk on its own.
- Treat solid fuel cooking as a special case. Charcoal, wood-fired or ember-producing equipment can introduce smoke, spark and fire-safety considerations that may not be easy to retrofit.
- Allow for operational impacts. If ventilation is undersized, the result can be heat, odour, grease deposition, poor staff comfort, higher cleaning demand and complaints from neighbouring tenancies or occupants.
‘Build a kitchen ventilation review into any lease change, refurbishment, compliance review or equipment replacement process. This reduces the risk of discovering a non-compliance after the tenancy layout, procurement or construction program is already locked in.’
What The standards update means for new kitchens
For new buildings and new fitouts, the main opportunity is to design the kitchen around the 2024 requirements from the outset.
- Classify the cooking processes early. The equipment schedule should be reviewed before the kitchen plan, hood dimensions and exhaust system are finalised.
- Allow enough space for larger hoods where required. Increased overhangs can affect bench layouts, circulation space, ceiling services and coordination with lighting, sprinklers and structure.
- Coordinate exhaust, make-up air and discharge routes at concept stage. Changes to exhaust rates can affect plant space, riser sizes, roof penetrations, acoustic treatment and energy use.
- Plan for future tenancy flexibility. In retail, hospitality and mixed-use buildings, a tenancy that can only support low-impact cooking may be harder to lease or adapt later.
- Identify solid fuel cooking early. If wood, charcoal or ember-producing equipment may be used, the kitchen, exhaust system and fire safety strategy should be planned around that risk from the start.
- Use the standard as part of the approvals strategy. Clear ventilation assumptions can reduce redesign, authority questions and late coordination issues during documentation and construction.
Reduce your compliance risk
The 2024 update to AS 1668.2 does not mean every commercial kitchen needs major redesign. However, it does mean you should review all assumptions in design. Equipment classifications, hood dimensions and exhaust requirements should be assessed early, particularly where kitchens are being upgraded, reconfigured or prepared for new operators.
By considering the changes at the start of a project, building owners and project teams can reduce compliance risk, avoid late redesign and make better decisions about space, services and future tenancy flexibility.
