Start of construction for a construction project without plans

On 22 May, construction work will begin on the extension of an office building for Basler & Hofmann in Esslingen in the canton of Zurich. The unusual thing about this construction start is not the building – a two-storey extension with offices and a cafeteria – but the planning and construction process: Basler & Hofmann is implementing the possibilities of building information modelling (BIM) in its own construction project in a way that is still rare in Switzerland.

BIM essentially means that all specialist planners work simultaneously in the same program on the same digital model and have a well-coordinated planning process for doing this. The digital model is the only basis for construction – both for the tender and for the construction site. Plans are non-existent, and after completion, the model is used directly for the ongoing management of the building. “This enables us to exploit the full potential offered by the new digital tools,” explains Dominik Courtin, who as Chairman of the Executive Board is also the client for this project. “For the construction industry in Switzerland, this approach is still groundbreaking. We have therefore consciously decided to use our own construction project as a pilot and to experience at first hand how building with BIM changes processes and tasks for the client, architects, planners and entrepreneurs.”

Real-time coordination required

With the start of construction, an intensive planning process will come to an end in which the team has had to learn quickly with and from each other. “If everyone is working in the same model, a two-week planners’ meeting is no longer enough. What you need is new and more closely timed alignment to enable continuous real-time coordination,” says Mathias Kuhn, Digital Planning Process Manager. “With the new digital possibilities, it is more important than ever to talk to each other.”

Planning phases shifted forward

The traditional construction phases, too, are shifted forward if full use is made of the possibilities offered by BIM. If the BIM database is to serve as the basis for the tender, all cost-relevant components must be modelled before the start of construction. Implementation planning must be completed in full before the contract is concluded, and therefore decisions have to be taken much earlier in some cases. “We have gained valuable experience on how to manage this process,” says Mathias Kuhn. The next decisive phase will now begin with the construction work. How does building according to a digital model work without plans? The learning process is far from over, that’s for sure.

Esslingen – Basler & Hofmann’s development laboratory

The Esslingen office has always been Basler & Hofmann’s own development laboratory. The company has time and again set new standards with its own office buildings here: in 1996 with the first Minergie office building in the canton of Zurich; and in 2010 with an almost energy self-sufficient office building whose energy requirements are covered by the sun all year round thanks to an innovative underground storage-tank concept. “Our customer projects benefit enormously from the experience we gain on their behalf in these pilot projects,” explains Dominik Courtin. With the extension building, the company is continuing this tradition, and it will be interesting to see what new insights they gain this time.

Parties involved in the construction project:

Client: Basler & Hofmann AG
Overall project management: Basler & Hofmann AG
Architecture: Stücheli Architekten AG
BIM coordination: Basler & Hofmann AG
Specialist planners (structural engineering, foundation engineering, building services, structural physics/acoustics, fire engineering, service piping): Basler & Hofmann AG
Facade planning: feroplan engineering ag
Building contractor: Marti AG