School building from Swiss wood
19.11.2021
National Councillor Erich von Siebenthal and Thomas Lüthi from the Initiative Holz BE presented the certificate to the president of the municipality Christian Däpp last Friday. It proves: The Aeschi school is built from Swiss wood. The showcase project was already put into operation by the students in Aeschi last spring.
Wood construction is gaining significantly in market share throughout Switzerland. There are good reasons for this: Wood is by far the most climate-friendly building material. The naturally renewable raw material requires only only solar energy and water for its production. Harvesting and processing require very little and the material also stores the greenhouse gas CO₂. In the wood, used in the Aeschi school building permanently stores 652 tons of CO₂. stored.
Originally planned in
Steel and concrete
The old school building in Aeschi near Spiez, built in
year 1909 has reached the limits of its capacity. A new three-story building in
wooden construction now extends the school building. Originally, a project made of
reinforced concrete was planned. Thanks to the persuasion of various stakeholders, a modern
modern wooden building - with wood from the surrounding community forests - stands next to the
the old school building.
Own wood in
public buildings
Since
January 1, 2021, the new public procurement law (BöB) has been in force. Here a paradigm
a paradigm shift towards more sustainability and quality competition.
Procuring good quality is an advantage for everyone. Because: A too strong
price weighting has inhibited suppliers from offering innovative solutions.
New award criteria such as "innovation" make it possible to reward good solutions.
reward good solutions.
The BöB is thus an opportunity for even more timber construction projects and innovative technologies. Let's tackle them together! The BöB also has its pitfalls. For example, in the procurement of regional wood. Public construction projects that exceed the threshold value of 9.575 million Swiss francs must be be put out to public tender. The same applies to the services of the (e.g. carpentry work) or individual supplies (e.g. cutting of logs). cutting of logs), if they exceed the threshold value of 500,000 Swiss francs or 250,000 francs respectively. New construction projects such as the Aeschi school building must therefore be be put out to public tender. According to the principle of principle of non-discrimination, no requirements may be imposed with regard to the be made with regard to the origin of the material. Swiss wood or wood from a certain area around the construction is not permissible.
However, there are ways in which wood from the public tender, wood from the surrounding area can be used: The The provision of wood by the builder himself, so-called in-house procurement, is one of them. in-house procurement, is one of them. Communities such as Aeschi, which have large forests of their own forests may provide the raw material and define this in the tender. define this in the invitation to tender. It is also particularly interesting that the degree of processing of the products is optional. This means that whole logs, sawn timber or glued products can be provided.
Two options for in-house procurement
| Direct use of wood from own forests | Indirect use of wood from own forests |
|---|---|
| Direct use ensures that the wood felled in the company's own forests is actually used for a specific construction project. Each tree felled is planned for a specific use and its traceability is guaranteed at all times. | In indirect use, the same amount of wood is cut as is used for a specific construction project. This principle allows a forest owner to use his own resources. The wood is not used directly for the specific construction, but the same quantities of wood are traded on the Swiss market. |
Early decision
necessary
For the planning process, it is crucial that the decision to use
that the decision to use regional wood is made early.
Timber can only be harvested in winter, so planners and builders need to know which trees
therefore need to know in the fall which trees will be needed for the project.
At the very least, a rough plan of cross-sections, including reserves and the
approximate proportion of hardwood and softwood, is essential at this stage.
Skilful
Planning
The extension building cleverly combines the wood
and frame construction: All load-bearing walls and the floor slabs
are made of glued laminated timber. The interior walls are
non-load-bearing frame structures. For the facades, largely knot-free
fir boards were used for the facades. A dry-bonded fill (Köhnke chippings) was used as
(Köhnke chippings) was used as sound insulation. Another exciting aspect of this project was the
the fire protection solutions: The vertical escape routes are designed as an encapsulated wooden construction.
wooden construction.
The school building has the special feature that an additional is already planned and can be easily carried out, because all components are all building components are dimensioned in such a way that the school building can be can be increased by one floor at a later date. For this purpose, the forces are are largely transferred via wooden columns that run through the entire height of the building and are and are clamped at the bottom. In addition, the interior walls are non-load-bearing, thus and thus allow maximum flexibility of use.
Client: Mixed municipality of Aeschi bei Spiez
Architecture: JAGGI FREI BRÜGGER architekten eth htl sia ag,
Frutigen
Holzbau ARGE Däpp Holzbau / Bärtschi Bau,
Aeschi b. Spiez
ARGE Cotting / Zurbuchen Holzbau und Sägerei, Aeschi b. Spiez
Building physics Weber Energie
and building physics, Bern
Facade planning
Müller Bernhard, Aeschi b. Spiez
Costs
BKP
1-9: CHF 8 million
BKP 2: CHF 6.792 million
BKP 214: CHF 1.396 million