Extension

An attic full of light

Apartment in Graz

"For me, light stands in the centre of each design; there is nothing more important than this. It is daylight that makes apartments homely and friendly."

- Martin Strobl Jr., Strobl Architektur

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Architecture: Architektur Strobl ZT GmbH

The history of the house is an interesting one. It was hit by a bomb during WW2 and rebuilt with a lower unsymmetrical new roof, not fitting the clear roofline of the neighbours. In 2008 a need for renovation of the old substance inspired the father and son duo to turn the student research into a project.

A new symmetrical roof was planned to match the gables left and right, which also - by introducing a longitudinal glazing along all facade - gave the possibility of raising the ceiling in the apartments below.

Building up on top of an existing house means a lot of restrains, especially through structure and cores. The ventilation shafts have to go up, and the extension has to stand on existing load-bearing walls. As the site is in the middle of the city, an efficient, prefabricated construction that could be assembled in minimal time was a must. Strobl decided to use also in this project cross-laminated timber. The material is ecological, the plates are cut to size in the factory and screwed together on site. Cross laminated timber (CLT) is light, which is another essential aspect in roof extensions of historic fabric.

Apartment in Graz with VELUX roof windows Architecture: Architektur Strobl ZT GmbH; Photos: Patricia Weisskirchner

Martin Strobl Jr.

Strobl Architektur

Velux is a long-time partner of our office. Sure, the products are great, but what I really appreciate is a partner to talk to when in doubt about daylight planning - we added the highlights thanks to VELUX analysis.

Apartment in Graz with VELUX roof windows

Architecture: Architektur Strobl ZT GmbH; Photos: Patricia Weisskirchner

Creating light-flooded rooms is not easy in a protected area, where dormers cannot be longer than 50% of the length of the house. Luckily a correct daylight distribution was taken under consideration very early in the design process. Martin Strobl jr. describes how it happened: "A VELUX representative was visiting the office to talk about another project. The first plans of the Schillerstrasse were lying on the table, we discussed them too. A 3D model created in the VELUX Daylight Visualizer tool showed that the corners as well as the ceiling were underlit."

Graphic

Architecture: Architektur Strobl ZT GmbH; Photos: Patricia Weisskirchner

A new, private staircase leads up to the light, to the spacious attic apartment. Due to roof form regulations in the old town only kitchen has a vertical wall and connection to the balcony. All other rooms are lit and ventilated from above.

The functions were located around the existing shafts and pipes, which resulted in an interesting typology of rooms. The bedrooms are traditional; their proportions remind of the apartments below. In the middle there is a light-flooded bathroom, lightning up the corridor through a transom window. The corridor and walk-through kitchen connect to the open living and dining area, divided into two zones by shafts, reminding of the classic room proportions.

The spruce plywood construction, glazed in translucent white, is visible inside, its delicate pattern replacing other wall decoration.

VELUX solutions used in this case

Roof windows

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