AOV Installations for new & existing residential blocks

Design, supply and fit of smoke ventilation systems across the UK — from single-stairwell jobs to full retrofits on 200-unit blocks. The preferred installer for many social housing clients.

How an AOV system works

Smoke ventilation in a residential block

Roof-mounted vents open automatically when smoke is detected, drawing smoke up & out of the stairwell to keep escape routes clear.

What we do

End-to-end AOV installation for the built environment

At BLEC Group we install and maintain all forms of AOV system, and also install addressable interfaces to existing AOV systems to modify them to automatic control. We are the preferred installer for many social housing clients and have been called upon to install AOV systems to new and existing residential blocks throughout the UK.

We install and maintain a vast array of equipment and have contracts in place with most manufacturers, ensuring we can provide suitable support to your property.

Manufacturer partners

Why every communal stairwell needs one

To comply with the latest building regulations, every communal stairwell must have an Automatic Opening Vent to extract smoke. Most large buildings contain sufficient air to sustain a substantial fire, so the well-known domestic advice to shut all doors in the event of a fire doesn’t apply — in fact the opposite does.

The greatest immediate danger to the occupants of a large building during a fire comes from the smoke, not the heat. Even a small fire can rapidly fill a large building with smoke to an extent where people escaping cannot see to find the escape routes and can be overcome by smoke inhalation. The recognised method of addressing this is to provide a smoke ventilation system with automatically operated roof ventilators.

How does it work?

In the case of a fire within a building, more than 60% of fatalities are caused by smoke poisoning. Smoke ventilation devices allow for the life-threatening smoke to be released into the open or to dilute its concentration. The danger is therefore reduced before smoke spreads through a building and escape routes like halls and staircases become impassable.

Automatic opening devices can be fitted to windows, roof-lights or doors. These devices are linked to a central control panel, complete with a battery backup system in case of mains failure. The control panel can then be triggered from either manual override switches local to the ventilator and the ground floor, by dedicated smoke detectors, or by interfacing with a third-party smoke detection / fire alarm system.

Worried about disruption?

Don’t worry — we’ll work alongside your existing contractors to minimise disruption. If we have to interrupt any utilities (gas, water or electric) to your premises, we’ll always notify you as early as possible so you can plan around it.

Why BLEC for your AOV

Built around your building, not a catalogue

Six things that come as standard on every BLEC AOV install — from initial survey through to final sign-off.

BS 7346-8 compliance

Every system designed and signed off to the British Standard for smoke control systems — fully documented, ready for building control.

Free site survey

A qualified engineer visits site to specify what's needed, quote the work, and walk you through it — no obligation.

In-house engineers

Every BLEC engineer is directly employed by us. No sub-contractors on your block — one accountable team, start to finish.

Minimal disruption

We coordinate with your existing contractors and residents. Utility interruptions are flagged early so you can plan around them.

Manufacturer contracts

Direct relationships with Velux, S E Controls, Window Master, Dyer and SCS — better parts pricing, faster lead times.

Ongoing servicing

Every install we deliver comes with the option of a scheduled service contract — keep it compliant, keep it covered.

Related compliance services

One team, end to end — AOV is just one part of what we look after for property managers.

AOV Servicing

Scheduled servicing to keep your AOV system fully compliant and operational. Annual contracts available.

AOV Maintenance

Reactive and planned maintenance for AOV systems — fault diagnosis, repairs, and full system overhauls.

Fire Alarm Installation

Pair your AOV with a BS 5839-compliant fire alarm system for full smoke detection & control coverage.

Client Feedback

Trusted by the UK's leading block managers.

Real reviews from the property managers, estate agents and freeholders we serve nationwide.

Common Questions

AOV install questions answered.

The questions we get asked most often when property managers are scoping an AOV install. If yours isn’t here, just call or drop us a line.

Still have questions?

Our team responds to enquiries within one working hour during business hours.

Call us · 01752 659415 →

How long does an AOV install take on a typical block?

Most single-stairwell residential blocks are completed in 3–5 working days, including roof works, control panel installation, and commissioning. Larger or multi-core buildings can take 2–3 weeks. We confirm a firm timeline at survey stage and stick to it.

Will residents need to leave during the install?

No. AOV installations are almost entirely external roof works and communal-area cabling, so residents stay in their flats throughout. Any utility interruptions (typically a short electrical isolation to install the control panel) are flagged at least 7 days in advance with letter-drop notices.

Which regulations does an AOV need to comply with?

The two key standards are BS 9991 (fire safety in residential buildings) and BS 7346-8 (components for smoke control systems). Approved Document B of the Building Regulations requires automatic smoke ventilation in any communal stairwell serving flats above ground level. Every BLEC install is designed to meet all three, with full sign-off documentation for building control.

Can you retrofit an AOV to an existing building?

Yes — retrofits are a big part of what we do. We can install roof-mounted vents, link them to existing fire alarm systems via an addressable interface, and bring older blocks up to current standards without major disruption. We’ve retrofitted AOVs to buildings ranging from Victorian conversions to 1970s tower blocks.

What happens if there's a power cut?

Every AOV control panel we install includes a battery backup sized to keep the system fully functional for the minimum standby duration required by BS 7346-8 — typically 72 hours on standby followed by 30 minutes of operation. The system fails safe to the open position if it ever loses power entirely.

Do you service AOVs you didn't install?

Absolutely. We hold manufacturer contracts with Velux, S E Controls, Window Master, Dyer and SCS — so we can service and maintain almost any system on the market. We start with a free system survey to inspect what’s in place and recommend a service schedule from there.