Minimum extractor hood height above hob: UK fitting checks

What sets the minimum extractor hood height above hob?

Start with the installation instructions for the exact hob and hood models. A search result giving one clearance in millimetres cannot account for different fuels, hood designs or the points from which each manufacturer measures. Look for the minimum installation distance in both manuals and check whether either gives separate instructions for gas, electric or induction cooking. If the manuals disagree, the proposed position must satisfy both.

Record the model numbers before measuring, especially if the appliances have not yet been delivered. Check that the instructions belong to the UK-supplied models rather than similar-looking versions sold elsewhere. Also look for a maximum recommended mounting height: a hood fitted above that range may not capture cooking fumes as intended. If a required minimum and maximum cannot both be met, ask the manufacturer or installer about a different appliance or layout.

Gather the instructions and mark the reference points

Download or retain the current installation manuals for the hob and extractor hood. On each clearance diagram, identify exactly where the measurement begins and ends. Depending on the appliance, the diagram may refer to the cooking surface, a gas pan support or another marked point, and to the lowest part of the hood. Write those reference points beside the clearance figure so that the later tape-measure check uses the same points.

Note any additional conditions, such as different distances for particular hob types or restrictions on fitting a hood above a gas appliance. Check the hood's overall dimensions, not just the width advertised on its product page: a chimney section, glass canopy or under-cabinet body may affect the available space. Keep a copy of both diagrams with the kitchen plan. This makes it easier for the fitter to check the proposed location before drilling.

• Record the full model number of each appliance.
• Write down each applicable minimum clearance in mm.
• Mark the start and end points shown in each manual.
• Note any maximum mounting height or special condition.

Calculate the clearance the layout must provide

Compare the minimum distances stated for your particular hob and hood. The larger applicable minimum is the first clearance your layout needs to provide; meeting only the smaller figure would leave one set of instructions unmet. If either manual specifies a different measuring reference, translate the proposed position onto a drawing with those points marked rather than treating the figures as directly interchangeable. Do not round a measured shortfall away.

Next, check any maximum height or positioning range stated for effective operation of the hood. The feasible position must be high enough to meet both minimum requirements while staying within any applicable upper limit. Record the chosen mounting height in millimetres and identify which hood edge or mounting line it refers to. A dimension labelled simply 'hood height' is too ambiguous for someone installing from a drawing.

Measure the kitchen before ordering or drilling

Measure from the finished position of the hob, allowing for the final worktop and any raised pan supports specified as measurement points. Use a tape measure and level to mark the proposed lowest point of the hood on the wall or cabinet elevation. Check the distance at more than one point if the worktop, cabinets or wall are not level. Record the smallest measured clearance, since that is the point most likely to fail the check.

Confirm that the hood body fits between adjacent wall units and that its doors, filters and grease screens can still be opened or removed for cleaning. Check the proposed position against splashbacks, shelves, sockets and the planned duct route. Many UK kitchens use a standard 600 mm-wide hob bay, but nominal widths do not confirm that a particular hood and its fixings will fit. Measure the actual space and use the product's installation dimensions.

• Measure the finished hob-to-hood clearance in mm.
• Check the narrowest point and any uneven surfaces.
• Confirm fixing positions and filter access.
• Check nearby cabinets and the duct route.

Check extraction and building-work implications

Decide whether the proposed hood will extract air outdoors or recirculate it through filters. These arrangements are not interchangeable when planning kitchen ventilation. Approved Document F provides guidance on ventilation for dwellings in England, including kitchen extract ventilation; check the applicable guidance for the property and location before assuming a recirculating hood meets a ventilation requirement. A hood that fits at the right height can still be the wrong choice for the ventilation plan.

For an externally ducted hood, check where the duct can run and terminate, and compare the route with the hood maker's installation instructions. Bends, cabinet space and the outside wall position may constrain the layout before the hood is fitted. If the work changes a regulated ventilation or electrical installation, establish whether building regulations approval or a registered installer's certification is needed. Requirements can differ across the UK, so confirm the rules that apply where the home is located.

Resolve conflicts before installation

If the measured space falls below either appliance's minimum, pause the fitting. Check the model numbers and diagrams once more, then consider changing the hood position, cabinet arrangement or appliance selection. Do not solve a shortfall by measuring from a more convenient point than the one shown in the instructions. Likewise, do not raise the hood without checking any upper mounting limit and the available duct and cabinet space.

Ask the appliance manufacturer or a suitably qualified installer to clarify instructions that appear inconsistent or incomplete. Gas appliance work must be handled by someone appropriately Gas Safe registered, and electrical work should be assessed against the rules applicable to the job. Keep written clarification with the manuals if it affects the final position. After fitting, retain the installation details so a future replacement can be assessed against the actual dimensions.

Final verification checklist

Before fixing the hood, compare the wall marks with both manuals and the finished hob position. Re-measure the clearance using the reference points specified for the installed models, including the lowest relevant part of the hood. Confirm that the measured distance meets every applicable minimum and any stated upper limit. Have the installer resolve a discrepancy before the holes are drilled.

After installation, confirm that filters remain accessible, the hood is secure and the chosen extraction arrangement matches the kitchen plan. Check that any required installation records or certificates are provided and store them with the appliance manuals. Photograph the finished clearance with a tape measure visible for the household records.

• Both exact model manuals are available.
• The measured clearance meets both sets of instructions.
• Any maximum height and access requirements are met.
• Ventilation arrangements and installation records are checked.

Scope and limitations

This note helps householders organise measurements and understand the calculation. It does not replace an on-site decision by a designer, installer, contractor, or manufacturer. Fabrication, structure, electrical work, gas, waterproofing, and personal safety require suitably qualified verification.