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Your building vision
becoming reality.

Overview

At JSI we specialise in tailored engineering solutions, from material selection to detailed execution plans for timber, steel and concrete buildings. With over 14 years of international experience, we help owners, architects and building designers transform building designs into reliable, high-performing structures.

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Our services

JSI offers engineering solutions for all types of constructions with sustainable and innovative ways forward.

Advice

For home and building owners, architects, builders and designers

Static and execution plans

For detailed timber, steel, concrete, brick buildings, or a combination of these materials.

Tendering

For adhering to quality and legal specifications with economic feasibility 

Structural design

For new constructions and renovations

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Featured projects

Stivai restaurant, Wil

The stylish bar and restaurant celebrates its 10th anniversary in a new guise. The sustainable construction, which can be dismantled at a later point and assembled in a new location, used regional resources that minimised the environmental impact, strengthened the local economy and enabled long-term use. 

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Extension of a residential building in Ossingen

The steel and timber structure, along with QSS fire protection and reinforcement of the existing building, was carefully engineered and optimized to ensure safety, durability, and seamless integration.

Zürich Film Festival

Together with partners S. Müller Holzbau AG, VierD and design agency Aroma we realised a new festival centre in modular timber construction on Zürich's famous Sechseläutenplatz. 

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Treehouse Sihlcity, Zürich

In the heart of Zürich's largest shopping mall, Sihlcity lies the large wooden treehouse construction. A bar and restaurant on three levels...

Client testimonials

Erwin Peter Construction Ltd

"JSI has a very competent and practice-oriented way of working! Solution-oriented and a flexible approach to static challenges. There is a detailed development in cooperation with the timber builders. And besides, which is very important for cooperation – a positive and upbeat personality!"

Let's chat about your next project!

Contact

 â€­+41 76 361 14 50‬

Disclaimer

Jan Stelcl Ingenieur GmbH
Blumenstrasse 2

8500 Frauenfeld
Switzerland

© 2025 Jan Stelcl Ingenieur GmbH.

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