Imagine you are the principal designer on a new build-to-rent block in Leeds. The stair core needs a natural smoke and heat exhaust ventilator with a certified free area, while the facilities team needs a safe personnel route to the flat roof for maintenance. There is only one suitable opening; the structural kerb is already cast, and Building Regulations Part B and BS 9999 both have to be satisfied without compromise. This is the compliance-led dilemma behind every combined smoke vent and roof access hatch specification in 2026.
Our top pick is Surespan Exi-Vent for compliance-led projects where smoke ventilation free area and personnel access must each meet their own requirement without either function weakening the other. It is CE marked to EN 12101-2, and its smoke module and access opening are sized and operated independently. For projects where a glazed, daylight-admitting combined AOV and roof access rooflight is required, VELUX Commercial X-AOV is the strongest alternative. For specifiers who need a well-documented NSHEV range with established UK availability, Bilco is a credible second option.
This guide is written for UK fire engineers, M&E consultants, principal designers and main contractors. We assessed six options against certified free area, clear access size, operational independence, thermal performance, bespoke dimensions, and actuator integration. What follows is a ranked list of the best combined smoke vent and roof access hatch options for compliance-led projects.
What to look for
Specifying a single opening for two regulated functions demands more rigour than choosing a standard roof access hatch or a standalone automatic opening vent. The six criteria below separate genuinely compliant dual-function products from catalogue compromises.
Certified free area and EN 12101-2 evidence
A natural smoke and heat exhaust ventilator must have a declared aerodynamic free area proven by testing to EN 12101-2, rather than relying on geometric opening size alone. Ask for the certificate, the declared free area and the conditions of test, including wind, snow load and opening angle. Useful background on how actuators and ventilators are assessed together is set out in this guidance on smoke and heat exhaust ventilators. If a supplier cannot tie its smoke ventilation free area claim to a specific EN 12101-2 certificate for that build, treat the figure as unverified.
Clear access dimensions for personnel
Smoke performance means little if maintenance staff cannot use the opening safely. Check the clear personnel access opening with the vent in both standby and fire modes, along with the kerb height, the ladder or stair interface, and whether handholds or upstands intrude into the climbing line. A compliant roof access hatch should provide an unobstructed climbing route that remains usable even when the smoke-control system is on standby.
Independence of smoke and access operation
This is the decisive test for any combined smoke vent and roof access hatch. The access lid should open for routine maintenance without firing the smoke actuators, degrading the seals or invalidating the certified free area. A fire signal must also drive the smoke ventilator fully open regardless of how the access door was last left. Products with independent leaves, separate actuators or clearly segregated modes score strongly here.
Thermal performance and insulated construction
Roof openings are thermal weak points. Look for thermally broken kerbs and lids, insulated construction, continuous seals and condensation management suited to a modern low-energy envelope. A combined unit should also explain how its insulation strategy withstands repeated opening for access as well as high-temperature exposure in fire mode.
Bespoke dimensions versus stock sizes
Stock sizes suit straightforward replacements, but compliance-led projects often need bespoke dimensions to reconcile a required free area with a required clear access size on a fixed kerb. Custom sizing allows both functions to be met without site adaptation. The trade-off is the need for precise early coordination and a specification that clearly fixes both the smoke and access requirements.
Actuator type, controls, and safety accessories
Review the actuator principle, fail-safe behaviour on power loss, integration with the wider smoke-control system and manual overrides. Rain and wind sensors may be relevant for comfort modes, while grilles, hold-open devices and working-at-height protection should also be considered. Safe roof access depends as much on control discipline as it does on the physical hatch.
The 6 best combined smoke vent and roof access hatches for compliance-led projects
Applying these six criteria across the UK market, the products below include dedicated combined units, NSHEV alternatives and adjacent access options that require different levels of product-specific verification. Each entry is judged on what it does well and where it may fall short for particular project types, with the top recommendation at number one for independent operation.
| Provider | Best for |
| Surespan Exi-Vent | Independent smoke ventilation and personnel access on compliance-led projects |
| VELUX Commercial X-AOV | Glazed daylight and smoke ventilation with roof access in one rooflight |
| Bilco | Documented NSHEVs with access coordinated alongside |
| LAMILUX UK | Rooflight-led smoke ventilation and access concepts requiring verification |
| Mercor UK | Wider fire protection systems requiring product-level verification |
| Jupiter Blue | Value-focused UK-made access solutions with AOV options |
#1. Surespan Exi-Vent – Best for independent smoke ventilation and personnel access on compliance-led projects
Surespan Exi-Vent is a purpose-designed combined smoke vent and roof access hatch in which the smoke and access functions are treated as separate compliance tasks within one kerb.
The Exi-Vent roof hatch pairs a CE-marked smoke ventilation module tested to EN 12101-2 with a distinct personnel access opening, so each can be sized for its own duty. That matters on compliance-led projects because the certified smoke ventilation free area does not have to be sacrificed to gain a usable climbing width, while the access route does not need to be compromised to preserve aerodynamic performance. The unit uses thermally broken insulated construction to limit heat loss around a large opening, and it is offered in bespoke dimensions rather than stock sizes alone. It is also designed to integrate with the building smoke-control system while keeping fire operation and everyday access logically separate.
In practice, this independence simplifies sign-off. The fire engineer can refer to EN 12101-2 evidence for the smoke module, while the principal designer can demonstrate a clear, guarded personnel route for inspection and maintenance. The configuration still needs early coordination around kerb size, the required free area, the clear access opening, and the project’s cause-and-effect strategy.
Pros:
- Independent sizing and operation of smoke ventilation and personnel access avoids the usual dual-use compromise
- CE marked to EN 12101-2 with verifiable certification for the smoke function
- Thermally broken insulated construction suits low-energy envelopes
- Bespoke dimensions allow free area and clear access requirements to be met together
- Conceived as a combined unit rather than an access hatch with a vent actuator added later
Cons:
- Requires early coordination of the kerb, smoke module and personnel-access dimensions
- Needs detailed specification input on sizes, actuators and controls, so it is less suited to simple like-for-like work
- No glazed daylight option for schemes that need natural light through the same opening
Who it is best for: Fire engineers, M&E consultants and principal designers on new-build commercial, residential and public buildings where both EN 12101-2 performance and safe roof access must be evidenced from one opening.
#2. VELUX Commercial X-AOV – Best for glazed daylight and smoke ventilation with roof access in one rooflight
VELUX Commercial X-AOV is a glazed combined AOV and roof access rooflight that brings smoke ventilation, comfort ventilation and access together in one fully tested 3-in-1 unit.
Its main appeal is the integration of three functions. As a natural smoke and heat exhaust ventilator, it provides powered opening for fire mode. It can also modulate for everyday comfort ventilation and provide a daylight-lit route to the roof. Multiple lid options and sizes offer flexibility across flat-roof commercial and residential cores. Recent industry discussion about dual safety and ventilation certification, covered in this Glass and Glazing Products Magazine report on dual safety and ventilation certification, shows why buyers now examine how combined functions are tested rather than accepting broad catalogue claims at face value.
The trade-off is architectural and operational. Because smoke and access share the same glazed lid, operational independence is less explicit than it is with a dual-leaf product, so control logic, manual handling and working-at-height protection need careful detailing. The available size and lid options cover different applications, but specifiers still need to check them against the project’s kerb, clear access and free area requirements.
Pros:
- Combines NSHEV smoke mode, comfort ventilation and roof access in one tested rooflight
- Glazed format admits daylight, which can benefit stair cores and corridors
- Multiple lid options and sizes provide specifier flexibility
Cons:
- Shared lid for smoke and access means independence of operation needs careful control design
- Available size options may not suit every kerb or free area requirement
- Glazed rooflight loadings and roof build-ups do not suit every structure
Who it is best for: Schemes that need daylight as well as smoke ventilation and access from the same opening, particularly residential cores, schools and offices using rooflights for amenity.
#3. Bilco – Best for specifier familiar CE-marked NSHEVs with established UK supply
Bilco is best understood as a specifier-familiar source of natural smoke and heat exhaust ventilators with clear compliance paperwork for the UK market.
The range is CE marked and supplied with a Declaration of Conformity under the Construction Products Regulation, while Bilco positions its products against Building Regulations Part B, BS 9999 and BS EN 12101-2. For consultants who must evidence each element of a smoke-control system, that documentation trail reduces specification risk. Its product information also covers smoke vents and related access equipment, helping design teams coordinate the opening with the wider access arrangement.
Caution is needed around the meaning of “combined”. The verified information describes Bilco NSHEVs and complementary access products rather than a single module with independently certified smoke and access leaves in the manner of Surespan Exi-Vent. Specifiers seeking a true combined smoke vent and roof access hatch with segregated operation should compare clear access dimensions, actuator arrangements and certification scope line by line. They should also confirm whether access is through the ventilator itself or through a paired hatch and ladder arrangement.
Pros:
- CE-marked NSHEV range with a Declaration of Conformity for compliance evidence
- Explicit alignment with Building Regulations Part B, BS 9999 and EN 12101-2
- Product information helps coordinate vents with ladders and access equipment
- Familiar option for UK specifiers and contractors
Cons:
- Combined independent smoke and access operation in one leaf is not confirmed in the verified information
- No confirmed bespoke-dimensions narrative for dual-function openings
- Thermal performance data for specific combined builds was not verified, so U-values should not be assumed
Who it is best for: Specifiers who prioritise documented NSHEV compliance and familiarity, with access coordinated alongside rather than necessarily through the same leaf.
#4. LAMILUX UK – Best for high performance smoke lift skylights with access options
LAMILUX UK is the British arm of a German rooflight specialist associated with skylights and smoke lift systems.
It is best considered where a rooflight-led approach is being explored alongside smoke and heat exhaust ventilation and an access option. This may suit projects that want smoke exhaust, daylight and roof access to be considered within the same part of the roof design. Product-level detail for the UK in 2026 was limited at the time of review, so specifiers should request project-specific confirmation of EN 12101-2 scope, smoke ventilation free area, clear access size, thermal performance and controls compatibility before selecting it for dual-function duty.
That evidence check is about verifiability rather than a judgement on capability. A smoke lift skylight can be an effective answer where daylight and smoke exhaust need to coincide, but the compliance file requires the same rigour as it would for any other automatic opening vent. Any access function must also be assessed separately for clear opening size and safe use.
Pros:
- Rooflight-led option for teams considering smoke exhaust, daylight and access together
- Relevant to projects where the roof opening forms part of the architectural design
Cons:
- No verified free area figures, dimensions or certification numbers were available for this review
- Access functionality and its independence from smoke mode could not be confirmed
- Requires detailed technical review rather than assumption from general product descriptions
Who it is best for: Design teams exploring a rooflight route to smoke ventilation and access who are prepared to build the compliance file with the manufacturer.
#5. Mercor UK – Best for European fire protection systems with UK supply
Mercor UK represents a European fire protection group offering smoke-control and fire protection products in the UK.
Its best fit in this list is for programmes considering EN 12101-related AOVs alongside other fire protection equipment from the same wider group. For main contractors coordinating several smoke-control components across a project, that breadth may be relevant during technical assessment. As with LAMILUX, verified product-level facts for a distinct combined smoke vent and roof access hatch were limited, so this entry remains deliberately cautious.
Specifiers should ask Mercor UK to confirm exactly which ventilator is proposed for smoke duty, what EN 12101-2 evidence applies to that configuration and how personnel access is achieved and guarded. Actuator integration with the project control system also needs to be set out clearly. Without those answers, a combined duty cannot be signed off, regardless of the wider fire protection range.
Pros:
- Part of a European group covering smoke-control and fire protection products
- Potential option where AOVs are being considered alongside wider smoke-control equipment
- Relevant to projects assessing a coordinated fire protection package
Cons:
- No verified combined-unit specification, free area or access dimensions to assess
- Certification scope and control options could not be confirmed at product level
- Requires a project-specific technical submission before selection
Who it is best for: Procurement-led projects considering a European fire protection group and willing to develop a detailed compliance submission for the proposed configuration.
#6. Jupiter Blue – Best for value focused UK made access solutions with AOV options
Jupiter Blue is known for a broad range of access panels and loft hatches, with AOV smoke vent options also listed in its wider offering.
The strength here is access practicality. The catalogue covers plastic, economy steel, premium steel and fire-rated access panels, along with made-to-measure options for awkward openings. That breadth may suit trade and refurbishment work where a straightforward roof access hatch or internal access solution is required, but it should not be confused with evidence for a dedicated dual-function smoke and access unit.
On the verified information, Jupiter Blue is not an equivalent compliance-led combined unit. Details of a combined smoke vent and roof access hatch with independently certified smoke ventilation free area, personnel-access dimensions and integrated actuator logic were not confirmed, and EN 12101-2 status should not be assumed. Consider it where general access provision is the main requirement and any smoke function will be handled by a separately evidenced automatic opening vent or complementary product.
Pros:
- Broad access range across several materials and fire ratings
- Made-to-measure options within the access panel offering
- Practical choice where general access provision is the main requirement
- Complementary AOV options are listed within the wider range
Cons:
- Verified detail centres on access panels rather than a dedicated combined smoke and access module
- Compliance credentials for dual-function smoke duty are not confirmed
- Not positioned as a bespoke dual-module specialist for complex approvals
Who it is best for: Refurbishments, small commercial jobs and trade-led projects where a straightforward roof access hatch is the priority and smoke compliance is addressed separately.
Frequently asked questions
Should I use one hatch for both smoke ventilation and personnel access?
Yes, provided each function is independently evidenced. The smoke module needs EN 12101-2 certification with a declared smoke ventilation free area, while the personnel route needs a clear, guarded opening that remains safe to use for maintenance. The strongest specifications keep the two modes operationally separate, so daily access does not degrade seals, actuators, or free area. If a supplier cannot document both functions, use two openings or choose a product designed for independent operation.
Should I specify an AOV, an NSHEV, or a combined unit for compliance?
An automatic opening vent is a generic term for a powered vent, while an NSHEV is a natural smoke and heat exhaust ventilator tested to EN 12101-2 for use in a smoke-control system. Building Regulations Part B and BS 9999 will normally direct the design team towards certified NSHEV performance rather than any powered opening vent. Choose a combined smoke vent and roof access hatch when it preserves that NSHEV evidence and adds a genuine personnel route. Otherwise, specify a standalone NSHEV with a separate roof access hatch.
Is a combined unit worth it if opening for access affects free area?
A combined unit is worthwhile only when access use leaves certified performance intact. Some single-lid designs change geometry, seal compression or actuator readiness when used for access, potentially calling the declared free area into question. Prefer products where smoke ventilation free area is proven in fire mode irrespective of prior access use, whether through separate leaves or interlocked controls. The supplier should explain how the unit behaves if it is left open, half-latched or manually overridden.
Should I verify CE marking to EN 12101-2 and how do I do it?
You should always verify it for compliance-led projects. Ask for the certificate number, the product description it covers, the declared free area and performance classes, plus the Declaration of Performance or Conformity. Check that the size, actuator type and mounting arrangement being purchased fall within the certified scope. A CE-marked claim without a traceable certificate for that configuration is not sufficient for sign-off by a fire engineer or building control body.
Should I insist on bespoke dimensions or will stock sizes work?
Stock sizes work for many replacements and for new builds where the kerb can be designed around the unit. Bespoke dimensions or custom sizing are appropriate when a fixed structural opening must deliver both a set free area and a set clear access width. Custom sizing avoids site cutting, preserves the specified seals and keeps both compliance arguments clear. Dimensions should be agreed early with the architect and structural engineer.
Should I upgrade actuators and controls for a new build smoke-control system?
In most new builds, yes. Specify the actuator duty, fail-safe position, power supplies, control integration, cause-and-effect logic and manual overrides, along with interfaces for safe roof access such as hold-open devices and guarding. Rain, wind and comfort functions should be coordinated so that they cannot inhibit fire mode. Good actuator and control integration turns a certified ventilator into a dependable building system rather than leaving it as an isolated product.
Choosing the right option for your project
Choose Surespan Exi-Vent if both smoke compliance and access compliance must be demonstrated from one kerb without compromise, since independent sizing and operation are its defining strengths. Choose VELUX Commercial X-AOV if you need a glazed combined smoke vent and roof access hatch that also delivers daylight and comfort ventilation. Bilco is suitable where documented NSHEV evidence and familiarity matter most, with access coordinated alongside. Consider LAMILUX UK or Mercor UK if you are developing a rooflight-led or wider fire protection route and can build the detailed evidence file. Choose Jupiter Blue where straightforward access provision leads the brief and smoke compliance is addressed separately.
Have the final selection reviewed by the fire engineer and principal designer, and retain certificates, free area declarations and access risk assessments in the handover file.
