Balcony door IOSU

High-quality, economical and very energy efficient Fenestra IOSU balcony doors are perfect for apartment buildings as well as private residences. The internal door of the double-framed balcony door opens inwards and the external door opens outwards. The internal frame consists of double glazing to ensure extra sound insulation. The outer frame and the external surface of the door leaf of the balcony door is covered with aluminium profiles. The doorsill of the balcony door is made of oak and the door has stopper systems to position the door just the way you need it. There are several design options available: the full glass, special mid-frame solution or the partially blocked balcony door. There are many different paint and stain options. All our products are tested by approved test labs.

The inwards and outwards openable balcony door IOSU

  • U-value up to 1,0 W / m²K
  • Durable and easy to maintain
  • Made of high-quality materials compliant with quality standard EVS-EN 14351
  • Wide selection of glazing
  • Selective glass insures world class thermal insulation
  • Balcony doors are custom made based on clients’ measurements and in compliance with the ISO 9001 quality system.


Wood has been selected and processed based on quality standard RT 103241. Architraves are made of glued laminated timber (pine) with at least three layers using weatherproof glue D4. Window frames are made of knotless pine and there are no finger joints on the visible stained/glazed surface.


Weatherproof and easy-to-maintain aluminium parts are powder coated or anodized. There are a wide range of colour options, ask for further information.


4 mm float glass is used as the standard glass for the outer frame while the frame on the inside is equipped with double SFS standard glazing.
The inside frame uses double glazing with selective surface, filled with argon gas. 4 mm glass is the standard choice for the outer frame.
Safety glasses, glazing for improved sound insulation and reduced solar radiation effect available with special orders.

Technical specifications of product


Standard architrave depth options 170 mm and 210 mm.
Recommended maximum door size 2.5 m²
Larger and smaller dimensions available for special solutions.

Insulation: ?

U-value with standard glass 1,0

Sound insulation: ?

Standard glass Rw = 42-47 dB
Ctr = 35-45 dB


We use TPE sealants.

Surface finish:

Wood details are coated in our factories with weatherproof paints (RAL), stains or lacquers (AkzoNobel TINTEX). There are a wide range of colour options.


Balcony door IOSU

Fenestra products come with handles and anti-closure latches included as standard. We can also provide you with suitable handles with a child lock for the windows and balconies that you need. There are a wide range of different models: explore our standard range below and find the right one for you.

Internal door handles:

External door handles:

Balcony door IOSU

Fenestra windows and balcony doors come in a wide selection of colours. Check out a suitable RAL or RR catalogue for preferred colours and the Akzo TINTEX catalogue for a preferred stain.

Balcony door IOSU

Window glazing can serve as a decorative element in the home or, where necessary, obscure the view from the outside or the inside. For example, Satinovo glass is an excellent choice for washrooms as it lets in light while shielding you from the eyes of outsiders. We offer something for everyone.

Balcony door IOSU

Stylish venetian blinds that match your home’s decor make life as convenient as possible. We recommend ordering them with the windows, as they are much more costly and time-consuming to install later.

Balcony door IOSU

Air vents help ensure functioning ventilation in your home by keeping indoor air fresh and healthy. The vents are designed to mix outdoor air with the warm indoor air in the upper part on the room, thereby avoiding draught.