bigAir® Roof



Plus Points that offer real value

For pitches down to 15°

Our bigAir® roof units are system-independent. They can be installed in any stick-system assembly, tile roofs and all other pitched roof types. They are ideal for ventilating halls and other spaces topped by roofs with pitches down to 15°.

A genuine all-rounder – for everything from innovative new-builds to historic properties. The potential applications are virtually unlimited. 

  • Modern industrial complexes
  • Innovative administrative facilities
  • Historic buildings
  • Listed properties 


More than a breath of fresh air

All Lacker louvre windows excel by their exceptionally high aerodynamic and geometric free area. For our roof louvres, this can be additionally optimized, where required, through installation of the Lacker-patented wind deflector system, which is concealed in the mullions. An optional extra which, above all, pays financial dividends.

Ready-assembled delivery

To allow prompt and trouble-free installation, we supply the windows as fully pre-assembled units complete with glazing. This allows straightforward fitting of our roof louvre windows – in much the same way as fixed lights – by any trade contractor, with no time lost through fine adjustment of hardware etc.

A full panoply of blades

Our bigAir® roof louvre units are manufactured, to your specifications, with

  • Double glazing
  • Triple glazing
  • Solar-control glazing
  • Insulated sheet-metal panels

The production heights for glass and panel blades range from 380 mm to 480 mm depending on the place of installation.

Filigree appearance

All blades are arranged in a filigree, structural-glazing-like composition, without horizontal frame members, and close flush at the sides with the adjoining glazing or tile roof. Horizontally, the stepped sequence of glass blades emulates the lapped arrangement of roof tiles.

Tiles are our model

The sophisticated lapped tile principle adopted by our louvre windows guarantees many years of weather exclusion. This is due to the prevention of damaging accumulations of dirt at the sensitive location of the glass weatherstripping and the efficient shedding of rainwater directly over the glass steps.

Quick and simple to replace

The intelligent, patented bayonet fastener system allows the prompt and straightforward replacement of damaged blades by any trade contractor.  

From big to small

As a general rule, our roof louvre windows are manufactured in minimum widths of 500 mm and minimum heights of 430 mm. The maximum width currently runs to around 5,900 mm and the maximum height to some 6,000 mm.

Size parameters

The achievable production sizes depend on the

  • surface area of the window
  • width-to-height ratio
  • snow loads to be accommodated
  • section thicknesses 


Made-to-measure advice

We should be glad to counsel you on the optimum window sizes for your particular scheme. With all due regard, of course, to your specific requirements and preferences. After all, our ultimate goal is to find the most economical solution for you and your project.   

Top pivots tilt the balance in our favour

For all Lacker louvre windows, the pivot is located in the upper part of the blade assembly. This allows the provision of two offset weatherstrips to ensure an absolutely weathertight barrier.

Continuous tilt up to 90°

The blades can be tilted at any angle up to 90°. The maximum opening angle is freely selectable. As standard, this value is preset to 85°.


The opening action of the window is such that the blades tilt outwards, with the edge of the top louvre moving away to the inside from the front edge of the weatherstrip. The system design is such that no part of the blades encroach on the internal space in either the open or closed position.

Hardwearing hardware

The hardware and motors for our bigAir® louvre windows are self-locking and remain weathertight even in the event of mains failure. This absolutely fail-safe, airtight hardware technology obviates the need for the separate locking mechanisms required by "soft" fastening systems.

Integral protection

Internally mounted bird or insect screens and safety rails can be readily integrated in the frame section of the louvre window.


Filigree sections

For our frames, we exclusively use highly insulating, thermally broken multi-chambered sections with 24 mm adapter thickness. The sections can be adjusted to fit all standard stick-system assemblies, steel sections and rafter constructions. Packing for greater adapter thicknesses and the widening of the adapter edge are feasible.

Every millimetre counts

Only filigree sections feature in Lacker's products. Depending on window size and structural requirements, the face widths generally range from 40 mm to 50 mm and the installation depths from 103 mm to 168 mm.

All colours of the rainbow

The frame sections are only visible from the inside and can be anodized or coated in any required RAL or DB colour.

Durably weathertight

All weatherstripping is made from ageing- and weather-resistant silicone or EPDM, with double-blade seal. Unlike standard brush seals, the weatherstripping materials and design guarantee full and reliable weather exclusion even after years of service.   

Driven by ingenuity

We use state-of-the-art single-motor (230 V and 24 V) technology with intelligent controls that makes synchronization problems a thing of the past. This solution also significantly reduces current consumption, failure risks and the cross-sections needed for the power supply cables.

Intelligent motor

Protection is enhanced through vandal-proof installation of the motor and drive system in the frame section. The window's present (open/closed) position status can, depending on the system, be signalled by the motor.

Connections included

The wiring for industrial communications networks (bus systems) or the central NSHEV station is integrated in the window and carried within the assembly to a single connection point.

Cables made to measure

As an optional extra, we supply our windows complete with cabling. Cable lengths vary from window to window and are adapted by us to meet project-specific requirements.

100% waterproof

For indoor swimming pools and other damp or humid spaces, we install our watertight drive system with IP 67 rating. This offers exactly the same functions and benefits as our standard drives.


Certified excellence

In all tests conducted by independent institutes, our bigAir® roof louvre windows exclusively deliver top results:

  • NSHEV test to DIN EN 12101-2:
    Test passed even under snow loads
  • Air permeability to DIN EN 12207:
    Up to Class 4 (product-dependent)
  • Driving rain resistance to DIN EN 12208:
    Up to Class E 1650 (product- dependent)
  • Resistance to wind load to DIN EN 12210:
    Up to CE 2.667 for positive pressure and
    up to 5.333 for suction (product-dependent)
  • Thermal transmittance:
    Up to UW 1.1 (depending on size and glazing)
  • Resistance to repeated opening and closing
    to DIN EN 1191:2000-08:
    Up to Class C (= over 33,000 cycles)

Optional Extras

Vapourproof and watertight drives

bigAir® louvre windows can be fitted with IP 67-rated electric motors to allow their use in indoor swimming pools, tropical gardens and other damp or humid spaces. 

Side-wind deflectors

Lacker's patented wind deflector system, which is concealed in the mullions, is recommended as a means of further enhancing the already above-average free ventilation area of all Lacker louvre windows.



Position status monitoring

The (open/closed) position status of bigAir® roof louvre windows can be monitored using reed switches or an incremental encoder system. 



Insect and bird screens

The outward-tilting blades of the louvre windows allow bird and insect screen systems to be readily fixed to the frame in the interior.    


Lacker emergency opening/closing system

Our manual emergency opening/closing system allows the operation of windows even in the event of mains failure.



Lifting lugs for crane assembly

We also strive to make our window systems fast and easy to install. Our window units are therefore supplied with lifting lugs for crane assembly upon request.