Mullion-transom construction from BUG: modular system offering versatile solutions and passive house level performance

Light is one of the most important elements of modern architectural design and comfort. This is achieved by using almost transparent facades and continuous glass surfaces. Using large-scale facade systems creates an open-plan living concept, generating a feeling of brightness, freedom and well-being. Additionally, the functional and design requirements for facade constructions are becoming more demanding. Maximum thermal insulation solutions at passive house level and the need for reliable load-bearing structures are just two important factors to consider.

As a system-oriented solution provider in the field of wood-aluminium windows, BUG fulfils its mission by offering a system solution for particularly large facade surfaces with discreet glazing options, such as the “Facade 50” mullion-transom construction. A weatherproof aluminium shell protects the solid wood and secures the glass pane with a sealing profile. The result is a valuable combination of two robust materials: sustainable wood for a carefully crafted finish, and high-quality aluminium profiles for delicate geometries. Overall, this system provides the substructure with optimum protection and is impressive due to its low maintenance requirements.

Maximum safety despite narrow external widths

Thanks to its narrow face widths of 50 millimetres, the reduced design of the BUG mullion-transom construction enables a threshold-free transition and opens up the space. This seamless design can be used for both single-storey and multi-storey mullion-transom facades. The wood-aluminium frame connections blend seamlessly into the building structure. Even large lift-and-slide doors can be installed to create a cosy ambience and connection between the inside and outside of the transparent building envelope.

With “Facade 50”, vertical building envelopes can be constructed using glass thicknesses of 24 to 52 millimetres and a filling weight of up to 450 kilograms per panel. The manufacturer’s top priority is the safety function, in addition to functionality and ease of installation. Thanks to the modern, screwless design, no compromises need to be made when designing transparent building envelopes.

Mullion-transom facade with integrated, stepless sealing system

Mullion-transom systems with thermally separated profiles and high thermal insulation can minimise thermal bridges and significantly reduce heating and cooling requirements. The “Facade 50” wood-aluminium construction, combined with PVC-free insulation profiles, provides the frame with high thermal insulation. The “Facade 50” can be optimised to meet high thermal insulation and energy efficiency requirements, including those of passive houses. Depending on the design, Uf values of between 0.8 and 1.7 W/m²K can be achieved.

A patented sealing system and integrated ventilation channels ensure controlled removal of condensation and moisture. The panel by panel separation of the glazing means that drainage levels are not required. Each glass panel is functionally independent and does not affect adjacent panels. This creates the most effective glazing rebate ventilation possible, which can be installed with minimal effort.

The modular design of the BUG mullion-transom construction also allows for flexible planning of large building openings and facade surfaces. Furthermore, the facade can be prefabricated by a specialist company and then simply assembled and installed on site. This simple design principle ensures a high level of installation safety.

BUG Aluminium-Systeme
Schachenstraße 14
88267 Vogt, Germany

Tel.: +49(0)7529 999 0
E-mail: bug.sales(at)step-g.com