© Bruno Klomfar

Building on

Building with and within existing structures has a very long tradition and is more important today than ever. Dealing with our existing building stock is a highly relevant aspect for climate protection and it will be one of the biggest challenges for our industry in the coming decades. The decisive factor in this context is not our buildings’ operation but the hidden grey energy over their entire life cycle. The most sustainable building is therefore the one that is already there. As much as the remodelling and extending of buildings is a challenge for architects and all those involved in planning and construction, it also holds and demands a great deal of creativity and flexibility, inspiring new and exciting ways to build.

Missed opportunities

Cities around the world are looking for ways to provide sufficient space for their rapidly growing urban population. In order to meet this demand, urban and municipal planning must activate the existing building stock as a basis for new developments. The issue of urban densification is directly linked to issues of energy and resources. The term „circular construction“ being omnipresent and much-discussed at the moment is a good thing. Nevertheless, far too many intact buildings are still being destroyed and replaced. While we wait too long to carry out repairs, we miss the opportunity to reposition our rich building stock for the future of our building culture. This applies to the function, structure, systems and aesthetics of a building (Music & Congress Centre in Strasbourg).

Life cycle and lightweight construction as part of the solution

One aspect of the solution are systematical changes over a building’s life by upgrading them in order to meet the changing new requirements (Hochreute Estate). Building within existing structures does not only mean modernising, neither is it only about extending them or adding storeys on top. It means developing sensible conversions. One important example is the transformation of office into residential space (transformation of the Velag site). Also, the best way for us to honor the history, origins and special features of existing buildings is to ensure that their continued use meets both today's functions and tomorrow's expectations (Angelika Kauffmann Museum). The demolition of an existing building must be properly assessed in order to take an informed decision whether it makes more sense to extend the use of a building or to recycle its components - depending also on the extend to which this is possible.

Particularly important within this context is the preservation and the continuing use of the existing load-bearing structure; This is also, where lightweight construction, building and extending with wood play an important role. Studies show that around a quarter of existing buildings would be strong enough to support additional storeys made of wood. A timber frame extension can be quick, sustainable and cost-effective. Their high degree of prefabrication make them predestined for inner-city construction sites that require short construction times and as little nuisance as possible. We successfully utilised these advantages back in 2006 for the Flachgasse roof structure in Vienna.

Full of surprises

Be it conversions, extensions, renovations or refurbishments - we as a practice have been able to acquire a lot of experience in this field since our early years. This still serves as a valuable resource for all current and future projects. Nevertheless, building in existing structures is full of surprises and these processes remain always exciting.  Every project - regardless of its size and importance -holds a new opportunity to reflect, emphasise and promote socio-cultural and ecological values.

Text: Barbara Fontana, February 2024

Wood in the City

The return of timber as a urban building material has by now been recognised at almost all levels. There are many arguments in favour of its use, enabling it to re-establish itself in the urban environment - also beyond high-rise buildings. In recent years, load-bearing structures made of wood have been built in cities around the world. The positive experiences made are encouraging. And also investors are increasingly focussing on this renewable building material.


The significance of place and craftmanship

The Vorarlberg region and the Bregenzerwald characterise the identity of Dietrich Untertrifaller. Every project that we bring to life carries a piece of this identity within it. Craftsmanship plays a key role in this - not in the sense of skills and qualities, but in the sense of attitude and appreciation of the context, resources and cooperation. In this respect, Vorarlberg symbolises far more than just the beginning of our history. Vorarlberg is sort of our laboratory, where everyone is the product of their environment, where we mutually benefit from each other through respectful interaction, joint discussions and open dialogue at eye level. The underlying aspirations we demand from ourselves and others is a constant element in our architecture and our approach.


Angelika Kauffmann Museum, Schwarzenberg (AT)
Continue building, Historic preservation


Rudolf Steiner School, Vienna (AT)
New building, Continue building


Elementary school Christian-Bucher-Gasse, Vienna (AT)
New building, Continue building, Refurbishment