If you're considering building a kitchen extension, you may be wondering if your kitchen extension ventilation needs a different approach to the measures you'd take for a standard kitchen.
Perhaps you're asking if you need different types of ventilation or can you use similar products? Or, if you're taking an open-plan approach to your kitchen extension does this change things?
We asked extension experts for their recommendations for getting your kitchen extension ventilation right, and here's what they have to say.
1. Why does a kitchen extension need ventilation?
The reality is you need ventilation throughout your whole house which means when designing an extension for any purpose, you will need to take into account any additional ventilation needs and requirements. However, in the case of your kitchen extension ideas, the need is even greater.
"All extensions will need some passive or natural ventilation," confirms Daniel McMurtry, sales manager at Simply Loft, "but as kitchens are prone to moisture from cooking, dedicated active ventilation such as cooker hood extraction, and natural ventilation, is vital."
Daniel McMurty
Daniel McMurty works at Simply Loft, part of the Simply Construction Group which provides design and build services for lofts, extensions and basement conversions across London and the West Midlands.
2. Is kitchen extension ventilation different?
Kitchen ventilation for any room where you cook involves making sure you have a number of ventilation requirements in place in order to combat mould, moisture and odours. Natural ventilation and the best kitchen extractor fans should all form part of your final design, but how does this differ from kitchen extension ventilation?
"Both are covered by the same regulations, which is Part ‘F’ of the UK building regulations," advises Daniel McMurty, "however the size of the kitchen extension in relation to the existing property, the amount of glazing, and the number of people likely to use the space will have an impact on the ventilation needs."
"Kitchen extension ventilation can differ to standard kitchen ventilation due to the specific characteristics and potential challenges associated with extensions," agrees Gregory Smith, property expert at Price Your Job. "Extensions are usually larger in size and have spaces with altered layouts which could create a less natural airflow. This may result in the need for more robust mechanical ventilations.
"If you are extending your kitchen, you could also be looking to cook more or engage in more intensive styles of cooking," he suggests. "This could lead to higher levels of cooking fumes, steam, or odours, demanding more powerful ventilation.
"As a result, the building regulations for extensions may impose stricter ventilation requirements to ensure compliance," says Gregory. "Newer extensions can have different air tightness properties and this can increase the risk of condensation if ventilation is inadequate, so it is important to add the appropriate levels of ventilation as needed."
Opting for a kitchen extension with a lot of glass such as an orangery kitchen extension could also make overheating potentially an issue, which is why regardless of the type of extension you are adding, it's important to make sure your kitchen extension ventilation is taken into account by both your architect and kitchen designer when planning and designing the new heart of your home.
This kitchen extension ventilation includes large patio doors for natural ventilation and a ceiling mounted cooker hood(Image credit: Simply Extend)
Gregory Smith
Gregory Smith has worked in the property and construction industry for over 20 years. He currently continues to work on domestic building projects while also providing expert comments in the property and construction field for PriceYourJob. He has worked with PriceYourJob for the past 4 years and has been published in a range of reputable publications.
3. Types of kitchen extension ventilation
Ventilating your kitchen extension well is achieved by combining a number of different types of ventilation.
"A combination of mechanical extraction, trickle vents which are small vents in window frames, purge ventilation such as opening windows or skylights, and positive input ventilation that pushes fresh air into a building can all be used in combination to satisfy your kitchen extension ventilation needs," says Daniel McMurty.
"You will first of all need an extractor fan or range hood," explains Gregory Smith. "This will directly remove cooking fumes, grease and steam from above the hob or range. It’s important to ensure the extractor fan’s capacity is appropriate for the size of the kitchen and the type of cooking that you do. Powerful cooking styles such as grilling or frying will require a higher capacity.
"Natural ventilation is also important," he confirms. "Make sure there are large, openable windows. These will allow fresh air to circulate and help remove odours and steam. Also make sure there are doors leading to the outside or other well-ventilated areas as these will also contribute to natural airflow.
On the rare occasion you can't vent externally (unlikely with a kitchen extension being newly built and having external walls), "choose a recirculation/filter cooker hood system which will remove oily particles from the air and create a circulation of air," says Daniel, "but combine it with purge ventilation or PIV to help remove excess moisture from the room." Natural house cooling ideas can all help too, which could involve using more window shading than you'd originally planned as one example.
Alternatively, if you are extending a terraced house with a rear extension but the kitchen will be located in your existing home meaning there isn't direct access to an external wall, choose an extractor system that can be ducted through the ceiling or walls to the closest external wall.
These extractor fans will provide mechanical ventilation in your extension
Hotpoint Phvp82fltk 80cm Chimney Cooker Hood - Black
A powerful extractor fan with touch control, three speeds and LED lights
Bosch Series 4 Dwk87fn60b Chimney Smart Cooker Hood - Black
This cooker hood is Quiet Mark certified and perfect for an open plan kitchen
Klarstein Hanging Island Cooker Hood, Extractor Fan for Kitchen Islands
Make a feature out of your ventilation with this hanging cooker hood above an island
4. How to design kitchen extension ventilation
When finalising the design for your kitchen extension ventilation, there are a number of ways in which you can ensure your kitchen layout ideas and ventilation work together to get the best end results.
First on the list is thinking about where your external vents or ducts will be running. "Position cooker hood extractors to allow the shortest possible ducting run to the outside," says Daniel McMurty. "The shorter the ducting the more effective the ventilation.
"A longer run will require a more powerful extractor which will generate more noise and typically use more power," he explains.
"You should prioritise ducted extractor fans that vent directly outside as this is the most efficient method for removing cooking fumes," says Gregory Smith. "Position the hob and extractor fan as close as possible to an external wall to reduce the ducting distance and use the recommended duct diameter for your extractor fan to ensure adequate airflow.
"Make sure to incorporate large, strategically placed windows that can be fully opened to help with ventilation," he adds. "Consider also installing bi-fold or sliding doors that open onto a patio or garden as this will allow for maximum airflow.
"Skylights can also help with ventilation if you choose ones that can be opened. Make sure to design the layout to encourage cross-ventilation and for the best airflow. For example, place windows and doors on opposite walls to create airflow," advises Gregory.
Make sure you include lots of natural kitchen extension ventilation when finalising your design(Image credit: Place Design/Chris Snook Photography)
FAQs
Will opening up the whole of the ground floor make a difference to kitchen extension ventilation?
"Yes it does," confirms Gregory Smith, "as this type of layout creates a much larger volume of air that needs to be ventilated. This means that a normal extractor fan may not be sufficient. Steam, grease and cooking fumes can travel further as there are no walls blocking the air from spreading.
"The steam and moisture from the kitchen area can also spread into the adjacent rooms and this can increase the risk of condensation and mould growth in other areas of the home.
"An open-plan extension often results in you needing a whole-house ventilation strategy such as a Mechanical Ventilation with Heat Recovery (MVHR) system. This can provide balanced ventilation throughout the combined space, ensuring consistent air quality and preventing condensation," says Gregory. Noting again the importance of natural ventilation and making sure your plans adhere to the latest building regulations.
Can I extend my MVHR system into a new extension?
"Yes, you can extend an existing MVHR system to a new extension," says Daniel McMurty, "but it requires careful planning to ensure proper ductwork design and system capacity to handle the additional space. You should consult with a qualified ventilation specialist to assess the feasibility and best solution for your home."
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Sarah is Homebuilding & Renovating’s Assistant Editor and joined the team in 2024. An established homes and interiors writer, Sarah has renovated and extended a number of properties, including a listing building and renovation project that featured on Grand Designs. Although she said she would never buy a listed property again, she has recently purchased a Grade II listed apartment. As it had already been professionally renovated, she has instead set her sights on tackling some changes to improve the building’s energy efficiency, as well as adding some personal touches to the interior.
