n Trondheim is currently underway. In April 2012, the author met with residents Mats and Hella to discuss their lifestyle choices. He learnt that there is now a long waiting list of students to move into this building; it has become very popular to be associated with this green building. The occupants mentioned that they like the idea that the building materials are recyclable and all tenants are conscious of the sustainability of the building, appreciating its particular ‘timber qualities’, for example the healthy indoor climate.
4.4. CLT Building 4: Am Muehlweg Complex, Vienna-Floridsdorf
The Am Muehlweg project was designed by Hubert Riess, Dietrich and Untertrifaller, and the construction cooperative Hermann and Johannes Kaufmann architects. One hundred public-sector apartments were built on each of three interconnecting plots, with the emphasis on the optimum exploitation of the ecological and economic benefits of timber and mixed constructions. Terraced houses and an L-shaped building surround an internal courtyard, creating a communal area. In total, the project provides 6750 sqm in 70 dwellings in 13 buildings (a detailed description of the project is in Kaufmann and Nerdinger ). The three-storey structures made from prefabricated CLT panels built on top of a concrete base were constructed in 15 months. The four-storey buildings offer two different solutions. The north-south-oriented terraced concept, with its maisonettes, has a two-storey timber construction on the second floor erected on top of a ceiling of reinforced concrete. The three-storey structures made from CLT elements are built on top of the concrete base of the east-west-oriented units (see Figure 6 and Figure 7 for images of the project). The entire four storeys of the building are clad in larch. An obligatory fire protection belt was included in the development’s design. Lattke and Lehmann  note that a major success of the project was the cooperative working relationships between planners and representatives of the public authorities, who discussed and developed alternatives and shared specific knowledge on timber construction. In April 2012, the author met with residents to discuss their lifestyle choices and reasons to decide for living in the building. The findings are similar to the Norwegian case: the occupants are very much aware of the ‘green’ construction method; they like the idea that the building materials are natural, and are conscious of the sustainability aspects of the buildings.
4.5. CLT Building 5: Wagramerstrasse Public Housing, Vienna
This is Austria’s highest residential building constructed with CLT systems: 101 apartments in a 7-storey slab along Wagramerstrasse and three 3-storey fingers forming courtyards. Six storeys of CLT sit on top of a concrete podium . The solution is the outcome of a 2009 design competition organized by the City of Vienna. The build is a composite structure of concrete cores with the CLT system; engineer Wolfgang Winter predicts that ‘most large-scale multistorey timber buildings in future will be hybrid structures, where sound insulation is typically added via the use of concrete or screed’ . The 2400 m3 timber structure stores around 2400 tonnes of CO2, which equals the annual emissions of 1630 cars. The panels were manufactured by Binderholz Bausysteme and the project is completed in February 2013. The apartments are 2, 3 and 4 bedroom units of 60 to 105 sqm in size; some are maisonettes.
4.6. CLT Building 6: The ‘e3’ Multi-Apartment Building at 3 Esmarchstrasse, in Berlin Prenzlauer Berg
The e3 apartment building, designed by architects Kaden and Klingbeil was only possible as a special exception to Berlin’s stringent building code. It is a seven-storey timber frame building, something still uncommon in ‘stone-built Berlin’; a hybrid construction using CLT panels for walls and glue-lam elements (the primary structural floor panels are in ‘Brettstapel’ method). Today, the majority of large multistorey timber structures are composites of different engineered timber systems . The wooden floor slabs a