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.

– Management   – Our Story   – Quality Management   – Experts

Dipl. Ing. Joachim Kantz

Dipl. Ing. Joachim Kantz

Managing Director

Mobile +43 664 80 944 410
j.kantz@okzt.at
Curriculum Vitae
Mr. DI Joachim Kantz graduated from the Graz University of Technology in the Department of Civil Engineering. During and after his studies he worked for the civil engineering offices Trauntschnig and Unterreiter on civil engineering projects and participated in the areas of ÖBA, accompanying control and PM.

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

Baurat Dipl. Ing. Heinrich Oberressl

Authorized Representative

Mobile +43 664 15 68 441
h.oberressl@okzt.at
Curriculum Vitae
Our mastermind and founding father, Mr DI Baurat h.c. Heinrich Oberressl, was born in 1936 in the beautiful Gailtal. In his apprenticeship years as a bricklayer, he quickly became a successful independent master builder and only as a late professional, he went to study at the Graz University of Technology.

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

Dipl. Ing. Wolfgang Obernosterer

Authorized Representative

Mobile +43 664 80 944 415
w.obernosterer@okzt.at
Curriculum Vitae
Mr. DI Wolfgang Obernosterer graduated from Graz University of Technology in the field of industrial engineering. During his studies, he gained first professional experience in the office of the Carinthian provincial government as well as in the civil engineering office Schnattler.

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

The foundation for our office as we know it today was laid in 1986 by Heinrich Oberressl. After two decades as a successful master builder, he decided to adjust his professional path and focused on civil engineering.

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.

With the arrival of Wolfgang Obernosterer in 2011, the three pillars of the company were also made visible to the outside world.

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 top priorities are high quality, timeliness and cost awareness. The high quality standard that our customers expect from us, we also demand from ourselves. In order to guarantee this high standard in the long term, we rely on continuous training and further education of our employees, as well as a dynamic development of our office processes, always adapted to the current focus and the respective task.

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

BM Dipl. Ing. (FH) Harald Rappauer

Team Leader Building and Industrial Construction

Mobile +43 664 80 944 443
h.rappauer@okzt.at
Ing. Carmen Kupper

Ing. Carmen Kupper

Planning, Tendering, Accounting

Mobile +43 664 80 944 419
c.kupper@okzt.at
Hanjo Hunger

Hanjo Hunger

Building Construction, Local Construction Supervision

Mobile +43 664 80 944 437
h.hunger@okzt.at
Dipl. Ing. Marta Cadez

Dipl. Ing. Marta Cadez

Planning Building Construction, Local Construction Supervision

Mobile +386 41 745 349
m.cadez@okzt.at
Ing. Mario Hochkircher

Ing. Mario Hochkircher

Building and Industrial Construction

Mobile +43 664 80 944 442
m.hochkircher@okzt.at
Ing. Georg Wald

Ing. Georg Wald

Project Control, Project Management, Local Construction Supervision

Mobile +43 664 80 944 421
g.wald@okzt.at
Julia Eggartner

Julia Eggartner

Planning, Accounting, Project Preparation

Mobile +43 664 80 944 421
j.eggartner@okzt.at
Dipl. Ing. Matjaž Gorkič

Dipl. Ing. Matjaž Gorkič

Planning Building Construction, Local Construction Supervision

Mobile +386 31 734 007
m.gorkic@okzt.at
Dipl. Ing. Damjan Grum

Dipl. Ing. Damjan Grum

Planning Building Construction, Local Construction Supervision

Mobile +386 31 838 555
d.grum@okzt.at
Ing. Klaus Schager

Ing. Klaus Schager

Team Leader Statics

Mobile +43 664 80 944 413
k.schager@okzt.at
Ing. Johannes Taupe

Ing. Johannes Taupe

Deputy Team Leader Statics

Mobile +43 664 80 944 420
j.taupe@okzt.at
Dipl. Ing. Ožbej Zih

Dipl. Ing. Ožbej Zih

Planning, Construction Management

Mobile +386 41 315 834
o.zih@okzt.at
Dipl. Ing. Vesna Javiljak

Dipl. Ing. Vesna Javiljak

Static Analysis

Mobile +43 664 80 944 426
v.javiljak@okzt.at
Dipl. Ing. Miha Brodnjak

Dipl. Ing. Miha Brodnjak

Static Analysis

Mobile +43 664 80 944 448
m.brodnjak@okzt.at
Mag. Ing. Marin Ribic

Mag. Ing. Marin Ribic

Static Processing

Mobile +43 664 80 944 428
m.ribic@okzt.at
Robert Filipovic

Robert Filipovic

Static Processing

Phone +43 463 44 44 40-435
r.filipovic@okzt.at
Patrick Winkler

Patrick Winkler

Static Processing

Mobile +43 664 80 944 440
p.winkler@okzt.at
Dipl. Ing. (FH) Thomas Scherzer

Dipl. Ing. (FH) Thomas Scherzer

Planning, Funding Applications, Project Management, Local Construction Supervision

Mobile +43 664 80 944 417
t.scherzer@okzt.at
Ing. Josef Juvan

Ing. Josef Juvan

Planning, Local Construction Supervision

Mobile +43 664 80 944 424
j.juvan@okzt.at
Paul Brkic

Paul Brkic

Planning, Funding Applications, Local Construction Supervision

Mobile +43 664 80 944 427
p.brkic@okzt.at
Leon Löscher

Leon Löscher

Planning, Funding Applications

Mobile +43 664 80 944 445
l.loescher@okzt.at
Dipl. Ing. Philipp Brandstetter

Dipl. Ing. Philipp Brandstetter

Planning, Funding Applications

Mobile +43 664 80 944 446
p.brandstetter@okzt.at
Miguel Marquez-Izquierdo, BSc.

Miguel Marquez-Izquierdo, BSc.

Planning, Funding Applications

Mobile +43 676 849 864 449
m.izquierdo@okzt.at
Daniela Natali Bakk.phil.

Daniela Natali Bakk.phil.

Management Assistant

Phone +43 463 44 44 40-411
d.natali@okzt.at
Dipl. Ing. (FH) Jenny Haßler

Dipl. Ing. (FH) Jenny Haßler

Administration

Phone +43 463 44 44 40-412
j.hassler@okzt.at
Dubravka Tschetschonig

Dubravka Tschetschonig

Accounting

Phone +43 463 44 44 40-431
d.tschetschonig@okzt.at
Matea Antunovic, BA MA

Matea Antunovic, BA MA

Administration

Phone +43 463 44 44 40-412
m.antunovic@okzt.at
Susanne Lebitsch

Susanne Lebitsch

Administration

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