Refurbishment and Restoration

Freiburger Hof

Freiburg i.B., Germany

Street view 1 | Street view
The attractive vertical extension of the heritage-protected “Freiburger Hof” shows how to realize urgently needed urban floor area in a sensible way of redensification.
Design: The „Freiburger Hof“, constructed around the year 1900, was substantially damaged in World War II and then vertically extended with an additional floor and a pitched roof in the 1950s. A recently realized new extension created new spaces for events and offices in a special atmosphere within 6 months building time. At the same time it is giving the historical facade of the building a contemporary conclusion that is true to its historical heritage. The rooftop was redone as a mansard roof with numerous dormers placed tightly side by side, citing its historical predecessor.

Wood: The mansard roof structure, cantilevered over a base area of 15x50 meters, was set on top of a massive timber ceiling built over the existing building structure. This likewise cantilevered cross-laminated timber ceiling with a thickness of 20 cm is tightly connected to the roof and absorbes the shearing forces. The entire construction consists of prefabricated CLT elements. This vertical extension serves as an exemplary solution for how to meet the demand for space in urban areas by redensification without burdening the neighborhood with time-consuming construction work. The optimized planning and prefabrication process also made for the economically most sensible solution.
Before the vertical extension 2 | Before the vertical extension
Construction process 3 | Construction process
Interior 4 | Interior
Basic information
Year of Completion |  2013
Investor |  W+S Maschinenbau GmbH, Freiburg i.B. (DE)
Architecture |  Höfler & Stoll Architekten, Heitersheim (DE)
Structural Engineering |  Göppert Bauingenieure, Lahr (DE)
Construction Time |  6 months
Number of floors |  1
Plot size |  736,92 m²
Gross floor area |  732 m²
Construction Costs (netto) |  2 538 €/m² GFA
Awards |  Holzbaupreis Baden-Württemberg 2015 (Recognition)
Photography |  Photo 1, 4: Ralf Killian, Vogtsburg-Oberrotweil (DE); Photo 2-3: Höfler & Stoll Architekten, Heitersheim (DE)

Technical aspects
Concept |  Structural system made of cross-laminated timber (240 mm)
Woodworking |  Zimmerei Steiger+Riesterer, Staufen (DE)
Origin of Timber, Certification |  PEFC wood for trusses: Österreich (AT)
Traceability of Timber |  Guaranteed by certification
Forestry Value Chain |  All companies involved are from the local area
Energy Systems |  Air-water heat pump
Energy Consumption  |  107 kWh/m²a (heating energy demand)
U-Value Wall | Roof | Floor | Windows (W/(m²K)) |  0,13

Regional Wood Energy Efficiency

Site Plan Site Plan Floor Plan Floor Plan Cross Section (Eaves/Dormer) Cross Section (Eaves/Dormer)