About Us
Get to Know Us
Meet our motivated and professional experts who are responsible for planning and implementing your projects, learn more about the history and development of OBERRESSL & KANTZ ZT-GmbH and gain an overview of our certified quality management system, which forms the basis for our work.

Curriculum Vitae
In 1994, he joined the office of Dipl.-Ing. Heinrich Oberressl as project and office manager. In 1998, after successfully passing the civil engineering examination, he became partner and managing director of Oberressl & Partner ZT-Ges.m.b.H.
In 2000, he was included in the list of experts of the Klagenfurt District Court. His main activities include project management for building construction, commercial and industrial facilities and municipal infrastructure.
Since 2008, Mr. Kantz is registered at the Slovenian Chamber of Engineers.

Baurat Dipl. Ing. Heinrich Oberressl
Authorized Representative
h.oberressl@okzt.at
Curriculum Vitae
After his studies he changed to the planning division in 1986, and has been working as a civil engineer and a court-certified expert since then. The most important thing that Heini taught us during his years of being actively involved in the company is that, in addition to organisation and specialist knowledge, more important attributes are required of a civil engineer.
These attributes are, and they also describe him and his personality, cordiality, modesty and a lot of heart and brain.

Dipl. Ing. Wolfgang Obernosterer
Authorized Representative
w.obernosterer@okzt.at
Curriculum Vitae
After successfully completing his studies, he joined OBERRESSL & KANTZ ZT-GmbH in 2000, as a project manager of the department of hydraulic and urban engineering. His activities are mainly focused on project management in the field of water supply and sanitation. This includes planning, submission, tendering, the handling of subsidies, as well as local construction supervision. In addition, Mr. Obernosterer also manages projects in the field of structural engineering and road construction.
Since 2011, Mr. DI Wolfgang Obernosterer has been an authorized representative of OBERRESSL & KANTZ ZT-GmbH.
Our Story
In 1994, Joachim Kantz joined the company as project manager, whereupon Oberressl & Partner ZT GmbH was jointly founded in 1998.
From 2002 to 2004, the first expansion steps towards Slovenia and Croatia were taken.
In 2002, the office moved from Völkermarkter Strasse to Feldkirchner Strasse. Since 2008, the office has been located at its current location, Schleppe Platz.
In the first years we were mainly known for structural engineering, competences in the fields of building construction and urban water engineering were successively built up.
In the following years, our branch network was expanded with offices in Eberndorf (2015), Ljubljana (2015), Pula and Vienna (2018).
Our international orientation is also legally secured by the official approvals in our main markets Slovenia (since 2009), Croatia (since 2018) and the Czech Republic (since 2014), as this means that we are entitled to present to the relevant authorities in these countries.
Since 2018, we have been taking our first steps across the Atlantic and into Asia.
Quality Management & Philosophy
Our certified quality management system ensures that we optimize organizational and planning processes in our daily work. This enables us to continuously improve our internal processes and products.


Our strong team of experts

BM Dipl. Ing. (FH) Harald Rappauer
Team Leader Building and Industrial Construction
h.rappauer@okzt.at


Hanjo Hunger
Building Construction, Local Construction Supervision
h.hunger@okzt.at

Ing. Mario Hochkircher
Building and Industrial Construction
m.hochkircher@okzt.at

Ing. Georg Wald
Project Control, Project Management, Local Construction Supervision
g.wald@okzt.at

Julia Eggartner
Planning, Accounting, Project Preparation
j.eggartner@okzt.at

Dipl. Ing. Matjaž Gorkič
Planning Building Construction, Local Construction Supervision
m.gorkic@okzt.at

Dipl. Ing. Damjan Grum
Planning Building Construction, Local Construction Supervision
d.grum@okzt.at










Dipl. Ing. (FH) Thomas Scherzer
Planning, Funding Applications, Project Management, Local Construction Supervision
t.scherzer@okzt.at


Paul Brkic
Planning, Funding Applications, Local Construction Supervision
p.brkic@okzt.at

Dipl. Ing. Philipp Brandstetter
Planning, Funding Applications
p.brandstetter@okzt.at

Miguel Marquez-Izquierdo, BSc.
Planning, Funding Applications
m.izquierdo@okzt.at




Matea Antunovic, BA MA
Sekretariat (currently on maternity leave)
m.antunovic@okzt.at

Let’s Build Together
Send us a message and our experts will take care of your request – from comprehensive consultancy to realizing your project!