Office | Profile
Markus Gnuechtel and Michael Triebswetter founded GTL Gnuechtel – Triebswetter landscape architects in 1991 in Kassel, the city of the world famous nature park, the upland called Wilhelmshoehe. GTL is also active in China, where there is, starting 2005, a shared Peking office with Rainer Schmidt landscape architects. In 2007 the opening of a further office location followed in Duesseldorf.
The owners’ credo: to realise innovative designs with best possible perfection in detailed planning and project management. Participating in numerous competitions – usually announced as pan-European competitions – gives the office the opportunity to constantly break new grounds in conceptual thinking and in the final realisation and presentation of its design ideas.
Numerous awards in competitions – among them 30 mostly highest awards, e.g. the internationally highly recognised first award for Pier 40 (with TECarchitecure, Los Angeles) in Manhattan, New York, and several national and international Landscape Design Awards reflect GTL’s constant thrive for the best possible result.
When competing for the design, which is contemporary, and complies with the planning task, the basic questions at the beginning and during the design process are, however, simple: What is the spirit of the location? Were there formal and historical ideas and concepts in the past, which are related to the task? Can these historical concepts be translated into contemporary concepts of shape and material? How is the design integrated in the cultural context? The human being is in the centre of all thoughts: his longing for beauty, his love of nature as well as of art, his need for calmness as well as for hurly-burly, for certain security and excessive surprise, the way he loves to revel in memories, as well as the need for integration in the cultural context of his time.
As the task differs from project to project by nature, the replies to the basic planning tasks must turn out differently, too. Committed to the clarity of modernity and to the poetry of garden design motives and surprising design in their materials and use of details, the subsequent projects show a representative profile from the works of GTL.
Sonja Bruns
Dipl.-Ing. Landcape Architect
Corporate partner
+49 40 – 5379876 -71
| Since 2023 | Corporate Partner at GTL |
| Since 2022 | Member of Hamburgischen Architektenkammer |
| Since 2022 | Employee at GTL |
| 2016 – 2022 | Ramboll Studio Dreiseitl, Hamburg |
| 2012 – 2016 | Gerber Architekten und Landschaftsarchitekten, Hamburg |
| 2004 – 2012 | Breimann&Bruun Landschaftsarchitekten, Hamburg |
| 1998 – 2004 | Study Architecture Bauhaus University, Weimar / IUV University Venedig |
Katrin Mauer
Dipl.-Ing. Landscape Architect
Corporate partner
+49 40 – 5379876 -72
| Since 2023 | Corporate partner at GTL |
| Since 2022 | Employee at GTL |
| 2018 – 2022 | Breimann & Cie Landschaftsarchitektur, Hamburg |
| 2012 – 2017 | Gerber Architekten und Landschaftsarchitekten, Hamburg |
| Since 2012 | Member of Architektenkammer Hamburg |
| 2007 – 2012 | Breimann&Bruun Landschaftsarchitekten, Hamburg |
| 2004 – 2007 | GTL Landschaftsarchitektur, Kassel und Peking |
| 1997 – 2004 | Studied Landscape Architecture at Universität Kassel |
Michael Triebswetter
Dipl.-Ing. Landscape Architect
Corporate partner
michael.triebswetter@gtl-kassel.de
+49 561 – 78946 -38
| seit 2023 | Coroporate Partner at GTL Landschaftsarchitektur |
| 2017- 2022 | Sole Owner of GTL Michael Triebswetter Landschaftsarchitekt |
| 2011-2012 |
Visiting Professor, University of Kassel
|
| 2008 |
Lectureship Technical University München-Weihenstephan
|
| 1994 |
Lectureship at GhK Kassel
|
| 1991 |
Founded own office GTL | Gnüchtel Triebswetter Landschaftsarchitekten
|
| Until 1991 | WES & Partner, Hamburg |
| Until 1988 |
Studied Landscape Architecture at Technical University, München-Weihenstephan |
Issam Abdellatif
M.A. Landscape Architecture
Project team member
Joined GTL in 2024
issam.abdellatif@gtl-hamburg.de
040 – 5379876 -80
| 2011 – 2014 | Studied Landscape Architecture at Hochschule Anhalt in Bernburg |
Sadik Deniz Akman
M.Sc. Landscape Architect
Project team member, competitions, project team leader
Joined GTL in 2015
+49 561 – 78946 -51
| Since 2025 | Member of Chamber of Architects, Hesse |
| Until 2017 | Master’s degree in Urbanism and Urban Planning at Technical University of the Middle East in Ankara |
| Until 2013 | Bachelor’s degree in Landscape Architecture and Landscape Planning at Technical University of the Middle East in Ankara |
Philipp Appel
B.Sc. Landscape Architecture
Project team member
Joined GTL in 2024
0561 – 78946 -59
| 2018 – 2023 | Bachelor’s degree in Landscape Architecture at University of Kassel |
Helge Baake
B.Sc. Landscape architect
Project Team Leader, Construction management
Joined GTL in 2022
+49 40 – 5379876 -74
| Since 2020 | Landscape Architect, Hamburg Chamber of Architects |
| Until 2016 | Bachelor’s degree in Landschaftscape Architecture at Technische Hochschule Ostwestfalen-Lippe in Höxter |
Jule Benedix
M.Sc. in Landscape Architecture
Project team member, project team leader
Joined GTL in 2015
+49 561 – 78946 -24
| Until 2018 | Studied Landscape Planning and Landscape Architecture at University of Kassel |
Philipp-Emanuel Brandt
M.Sc. in Landscape Architecture
Project team leader, construction management
Joined GTL in 2016
+49 561 – 78946 -44
| Until 2016 | Studied Landscape Planning and Landscape Architecture at University of Kassel |
Annerieke Busch
M.Eng. Landscape Architecture
Project team member
Joined GTL in 2025
annerieke.busch@gtl-hamburg.de
+49 40 – 5379876 -81
| 2022 – 2024 | Master’s degree in Landscape Architecture at Fachhochschule Erfurt |
| 2019 – 2022 | Bachelor’s degree in Landscape Architecture at Fachhochschule Erfurt |
Duy Phan Do
M.Eng. in Landscape Architecture
Project team member, competitions
Joined GTL in 2018
+49 561 – 789 46 -65
| Until 2019 | Master’s degree in Landscape Architecture at University of Nürtingen-Geislingen |
| Until 2013 | Bachelor’s degree in Architecture and Planning at National University of Civil Engineering in Vietnam |
Lisa Elsner
M.Sc. Landscape Architecture
Project team member, construction management
Joined GTL in 2019
+49 271 – 693816 -4
| Until 2016 | Studied Landscape Architecture at Technische Hochschule Ostwestfalen-Lippe in Höxter |
Sebastian Elsner
B.Sc. in Landscape Architecture
Project team leader, construction management
Joined GTL in 2020
sebastian.elsner@gtl-hoexter.de
+49 561 – 78946 -34
| Until 2017 | Studied Landscape Architecture at Technische Hochschule Ostwestfalen-Lippe in Höxter |
Betty Pixiang Fan
Master.-Ing. Art Landscape Architecture
Project team member
Joined GTL in 2009
+49 561 – 78946 -33
| until 2008
until 2003 |
Studied Landscape Architecture, Anhalt University of Applied Sciences, Bernburg, Germany
Studied Landscape Architecture, Sichuan Agricultural University, Sichuan, China |
Luna Gille
B.Sc. Landscape Architecture
Project team member
Joined GTL in 2024
0561 – 78946 -45
| Until 2024 | Studied Landscape Architecture, University of Kassel |
| Until 2019 | Training as a landscape gardener |
Stefanie Grebe
M.Sc. Landscape Architecture
Project team member
Joined GTL in 2025
+49 561 – 78946 -26
| 2018 – 2025 | Studied Landscape Planning and Landscape Architecture at University of Kassel |
| 2021 – 2025 | Joined GTL as student assistent |
Sabine Gruber
B.Sc. in Landscape Architecture
Acquisition, Social media
Joined GTL in 2020
+49 561 – 78946 -43
| Until 2016 | Bachelor’s degree in Landscape Planning and Landscape Architecture at University of Kassel |
Yu Hao
M.Sc. in Landscape Architecture
Project team member, competitions
Joined GTL in 2014
+49 561 – 78946 -49
| Until 2017 | Master’s degree in Landscape Architecture and Landscape Planning at University of Kassel |
| Until 2010 | Bachelor’s degree in Landscape Architecture at Beijing Forestry University in Beijing, China |
Nicole Hohmann
State-accredited Business Economist
Accounting systems | Personnel management
Joined GTL in 2000
Carl Illian
Student, Cand. M.Sc.
Joined GTL as a student assistant in 2024
| Since 2021 | Studied Landscape Architecture and Landscape Planning at University of Kassel |
Franziska Itter
Student, Cand. M.Sc.
Joined GTL as a student assistent in 2023
| Since 2020 | Study of Landscape Architecture and Landscape Planning at University of Kassel |
Katharina Janusch
M.Sc. Landscape Architect AKH
Project team leader
Joined GTL in 2017
katharina.janusch@gtl-kassel.de
+49 561 – 78946 -39
| Until 2016 | Studied Landscape Planning and Landscape Architecture at University of Kassel |
Stefan Kettlitz
Landscape Architect AKH bdla
Project team leader, construction management
Joined GTL in 2016
+49 561 – 78946 -21
| 2013 – 2016 | Chairperson of the Hessen Regional Association of the Federation of German Landscape Architects |
| Until 1995 | Studied Landscape Planning and Landscape Architecture at University of Kassel |
| 1987 – 1990 | Studied for Intermediate Diploma in Landscaping at Technical University in Munich-Weihenstephan |
| Until 1987
Until 1984 |
Work as landscape gardener in Berlin and Bern
Trained as landscape gardener in Berlin |
Juliana Klusmann
M.Sc. Landscape Architecture
Project team member
Joined GTL in 2025
juliana.klusmann@gtl-kassel.de
+49 561 – 78946 -61
| 2022 – 2025 | Master’s degree in Landscape Architecture and Landscape Planning at University of Kassel |
| 2022 – 2025 | Joined GTL as Student Assistant |
| 2018 – 2022 | Bachelor’s degree in open space planning at Hochschule Osnabrück |
Stefanie Knoblich
B.Sc. Landscape Architecture
Competition
Joined GTL in 2025
stefanie.knoblich@gtl-kassel.de
+49 561 – 78946 -55
| 2022-2025 | Joined GTL as a Student Assistant |
| 2018-2025 | Study of Landscape Architecture and Landscape Planning at University of Kassel |
Melanie Lips
Architect
Project leader
Joined GTL in 2012
+49 511 – 8984 -471
| Until 2003 | Studied for Diploma in Architecture at Leibniz University Hannover |
Lena Louven
Student, Cand. M.Sc.
Akquisition
Joined GTL as a student assistant in 2024
| Since 2022 | Master’s degree in Landscape Architecture and Landscape Planning at University of Kassel |
| 2018 – 2022 | Bachelor’s degree in landscape architecture at Technische Hochschule Ostwestfalen-Lippe in Höxter |
Liming Meng
M.Sc. in Urban and Regional Planning
Project team member
Joined GTL in 2017
+49 561 – 78946 -58
| Until 2013 | Master’s degree in Architecture at Brandenburg Technical University in Cottbus |
| Until 2012 | Master’s degree in Urban and Regional Planning at Brandenburg Technical University in Cottbus |
| Until 2010 | Bachelor’s degree in Architecture at Brandenburg Technical University in Cottbus |
| Until 2004 | Bachelor’s degree in Visual Communication at University of Hangzhou in China |
Jannik Missing
Student, Cand. B.Sc.
Joined GTL as a student assistant in 2024
| Since 2021 | Study of Landscape Architecture and Landscape Planning, University of Kassel |
Joanna Müller
B.Sc. Landscape Architectur
Project team member
Joined GTL in 2023
05271 – 6938162
| 2021 – 2023 |
Joined GTL as a Student Assistant
|
| 2018 – 2023 | Bachelor’s degree in Landscape Architecture at Technische Hochschule Ostwestfalen-Lippe in Höxter |
Sara Nejatianrad
M.Sc. Landschaftscape architecture
Project team member
Joined GTL in 2017
sara.nejatianrad@gtl-kassel.de
+49 561 – 78946 -48
| Until 2018 |
Master’s degrees in Landscape architecture at Hochschule Anhalt in Bernburg
|
| Until 2011 |
Bachelor’s degrees in Industrial design at University of Mashhad in Iran
|
Manuela Parra
Trainee draughtswoman
Joined GTL as a team member in 2023
Carolin Peter
Student, Cand. M.Sc.
Competition
Joined GTL as a student assistant in 2022
| Until 2025 | Study of Landscape Architecture at University of Kassel |
Philipp Schäfer
Student, Cand. M.Sc.
Joined GTL as a student assistant in 2023
philipp.schaefer@gtl-kassel.de
| Since 2020 | Study of Landscape Architecture and Landscape Planning at University of Kassel |
Salma Sajadi
M.Sc. Sustainable Architecture and Landscape Design
Team member
Joined GTL in 2024
0561 – 78946 -46
| Since 10/2024 |
Team member of GTL
|
| 10/2023 – 10/2024 |
Joined GTL as a Student assistant
|
| 03/2023 – 09/2023 |
Internship at GTL
|
| 2016 – 2019 |
Working in Iran
|
| 2010 -2015 |
Bachelor’s degree in Architecture at Hafez University Shiraz in Iran
|
Sandra Sennhenn
Landscape Planner
Project leader
Joined GTL in 2010
+49 561 – 78946 -42
| Until 2010 | Studied Landscape Planning and Landscape Architecture at University of Kassel |
Tina Stamm
Landscape Architect
Project team leader
Joined GTL in 2012
+49 561 – 78946 -40
| Until 2009 | Studied Landscape Planning and Landscape Architecture at University of Kassel |
Sibylle Triebswetter
Economist
Management
Joined GTL in 1999
sibylle.triebswetter@gtl-kassel.de
+49 561 – 78946 -10
| Until 1995 | Studied Business Management at Hochschule Osnabrück |
Pia Urban
M.Sc. in Landscape Architect
Project Team Leader, Construction management
Joined GTL in 2021
+49 561 – 78946 -56
| Until 2021 | Studied Landscape Planning and Landscape Architecture at University of Kassel |
| 2018 – 2021 | Joined GTL as a Student Assistant |
Lars Weinerth
Dipl.-Ing. Landscape architect, M.Sc. Urban planning
Project Team Leader
Joined GTL in 2023
+49 40 – 5379876 -73
| Until 2009 | Master’s degree at HafenCity University Hamburg |
| Until 2006 | Diploma programme in Landscape Architecture at Technische Hochschule Ostwestfalen-Lippe in Höxter |
Ines Wodrich
Architect
Project Management
Joined GTL in 2001
+49 561 – 78946 -23
| Until 2000 | Studied Architecture at University of Kassel |
| Until 1992 | Diploma studies and engineering qualification in Building Materials and Silicate Technology at University of Freiberg |
Mingge Yu
Diploma in Design
Project leader, Product design, Competitions
Joined GTL in 2008
+49 561 – 78946 -53
| Until 2007 | Studied Product Design at Kunsthochschule Kassel |
| Until 2000 | Studied at Luxun Art Academy in China |
Zhenya Yurchick
Dipl.- Ing. Landscape Architecure
Project team member
Joined GTL in 2024
zhenya.yurchick@gtl-hamburg.de
040 – 5379876 -79
| Bis 2011 | Studied Landscape Architecur at Belarusian State Technological University in Minsk |
Yumeng Zhang
M.Sc. in Landscape Architecture
Project team member, competitions
Joined GTL in 2016
+49 561 – 78946 -22
| Until 2017 | Master’s degree in Landscape Architecture and Landscape Planning at University of Kassel |
| Until 2012 | Bachelor’s degree in Landscape Architecture at Beijing Forestry University in China |
Deborah Ziehlke
Student, Cand. B.Sc.
Joined GTL as a student in 2025
| Since 2022 | Study of Landscape Architecture and Landscape Planning at University of Kassel |
Andreas Körbs †
Landscape Architect
Project team leader, construction management
Employee at GTL from 2017 – 2024
| Until 1988 | Studied Landscaping at Hochschule Weihenstephan-Triesdorf with specialisation in space-planning |
| Until 1983 | Trained in gardening and landscaping |
I go before you into the peace of the
Lord and await you there
to eternal reunion
– St. Augustine
Obituary
Our dear colleague Andreas Körbs has left us far too soon. With his many years of experience, his professional expertise, his exceptional friendliness and his hands-on manner, he was a highly valued partner for our clients in the realisation of the most demanding construction projects. He not only supported us colleagues with advice and assistance in matters of planning and construction, he was also an attentive listener and advisor in all situations outside of work. As a fatherly mentor, he was particularly supportive of our young landscape architects. In Andreas, we are not only losing an outstanding landscape architect and a dedicated colleague, but also a friend.