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, 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 | Studied for Master’s degree in Urbanism and Urban Planning, Technical University of the Middle East in Ankara |
| Until 2013 | Studied for Bachelor’s degree in Landscape Architecture and Landscape Planning, 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 | Study of Landscape Architecture, 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 Architekt, Hamburg Chamber of Architects |
| Until 2016 | Bachelor’s degree in Landschaftscape Architecture, Hochschule Ostwestfalen-Lippe 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, 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, University of Kassel |
Duy Phan Do
M.Eng. in Landscape Architecture
Project team member, competitions
Joined GTL in 2018
+49 561 – 789 46 -65
| Until 2019 | Studied for Master’s degree in Landscape Architecture, University of Nürtingen-Geislingen |
| Until 2013 | Studied for Bachelor’s degree in Architecture and Planning, National University of Civil Engineering, 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, advanced technical college Ostwestfalen Lippe, 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
| Since 2017 | Studied Landscape Planning and Landscape Architecture, University of Ostwestfalen-Lippe, 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 | Studying Landscape Planning and Landscape Architecture, 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 | Studied Landscape Planning and Landscape Architecture, University of Kassel |
Yu Hao
M.Sc. in Landscape Architecture
Project team member, competitions
Joined GTL in 2014
+49 561 – 78946 -49
| Until 2017 | Studied for Master’s degree in Landscape Architecture and Landscape Planning, University of Kassel |
| Until 2010 | Studied for Bachelor’s degree in Landscape Architecture, Beijing Forestry University, Beijing, China |
Nicole Hohmann
State-accredited Business Economist
Accounting systems | Personnel management
Joined GTL in 2000
Carl Illian
Student
Joined GTL as a student assistant in 2024
| Since 2021 | Study of Landscape Architecture and Landscape Planning, University of Kassel |
Franziska Itter
Student
Joined GTL as a student assistent in 2023
| Since 2020 | Study of Landscape Architecture and Landscape Planning, 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, 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, University of Kassel |
| 1987 – 1990 | Studied for Intermediate Diploma in Landscaping, Technical University, Munich-Weihenstephan |
| Until 1987
Until 1984 |
Work as landscape gardener in Berlin and Bern
Trained as landscape gardener, 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, University of Kassel |
| 2022 – 2025 | Joined GTL as Student Assistant |
| 2018 – 2022 | Bachelor’s degree in open space planning at Osnabrück University of Applied Sciences |
Stefanie Knoblich
B.Sc. Landscape Architecture
Competition
Joined GTL in 2025
stefanie.knoblich@gtl-kassel.de
+49 561 – 78946 -55
| 2022-2025 | Student Assistant by GTL |
| 2018-2025 | Study of Landscape Architecture and Landscape Planning, University of Kassel |
Melanie Lips
Architect
Project leader
Joined GTL in 2012
+49 511 – 8984 -471
| Until 2003 | Studied for Diploma in Architecture, Leibniz University, Hannover |
Chiara Loffredi
M.Eng. Landscape architecture
Project Team Member
Joined GTL in 2023
chiara.loffredi@gtl-hamburg.de
+49 40 – 5379876 -76
| Until 2021 |
International Master of Landscape Architecture at the University of Applied Sciences HfWU Nürtingen-Geislingen
|
| 2015 – 2018 | B.Sc. Università di Roma La Sapienza und Università degli Studi della Tuscia |
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, University of Kassel |
| 2018 – 2022 | Bachelor’s degree in landscape architecture at TH OWL Höxter |
Liming Meng
M.Sc. in Urban and Regional Planning
Project team member
Joined GTL in 2017
+49 561 – 78946 -58
| Until 2013 | Studied for Master’s degree in Architecture, Brandenburg Technical University, Cottbus |
| Until 2012 | Studied for Master’s degree in Urban and Regional Planning, Brandenburg Technical University, Cottbus |
| Until 2010 | Studied for Bachelor’s degree in Architecture, Brandenburg Technical University, Cottbus |
| Until 2004 | Studied for Bachelor’s degree in Visual Communication, University of Hangzhou, China |
Jannik Missing
Student, Cand. M.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 | Studying Landscape Architecture, TH OWL 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, Hochschule Anhalt, Bernburg
|
| Until 2011 |
Bachelor’s degrees Industrial design, University of Mashhad, 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 | Studied Landscape Architecture, University of Kassel |
Katharina Schreiber
B.Sc. Landscape Architecture
Team member
Joined GTL in 2025
katharina.schreiber@gtl-kassel.de
0561 – 78946 -34
| 2021 – 2024 | Various jobs in garden centres |
| 2019 – 2023 | Study of Landscape Architecture , University of Kassel |
Philipp Schäfer
Student
Joined GTL as a student assistant in 2023
philipp.schaefer@gtl-kassel.de
| Since 2020 | Study of Landscape Architecture and Landscape Planning, 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 |
Student assistant at GTL Kassel
|
| 03/2023 – 09/2023 |
Internship at GTL
|
| 2016 – 2019 |
Working in Iran
|
| 2010 -2015 |
Bachelorstudies Architecture Hafez University Shiraz, Iran
|
Sandra Sennhenn
Landscape Planner
Project leader
Joined GTL in 2010
+49 561 – 78946 -42
| Until 2010 | Studied Landscape Planning and Landscape Architecture, 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, 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, University of Applied Sciences, 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, 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 programme, HafenCity University Hamburg |
| Until 2006 | Diploma programme, Landscape Architecture Hochschule Ostwestfalen-Lippe Höxter |
Ines Wodrich
Architect
Project Management
Joined GTL in 2001
+49 561 – 78946 -23
| Until 2000 | Studied Architecture, University of Kassel |
| Until 1992 | Diploma studies and engineering qualification in Building Materials and Silicate Technology, 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, College of Fine Arts, Kassel |
| Until 2000 | Studied at Luxun Art Academy, 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 Architecure, Belarusian State Technological University, Minsk |
Yumeng Zhang
M.Sc. in Landscape Architecture
Project team member, competitions
Joined GTL in 2016
+49 561 – 78946 -22
| Until 2017 | Studied for Master’s degree in Landscape Architecture and Landscape Planning , University of Kassel |
| Until 2012 | Studied for Bachelor’s degree in Landscape Architecture, Beijing Forestry University, China |
Deborah Ziehlke
Student, Cand. B.Sc.
Joined GTL as a student in 2025
| Since 2022 | Study of Landscape Architecture and Landscape Planning, University of Kassel |
Andreas Körbs †
Landscape Architect
Project team leader, construction management
Employee at GTL from 2017 – 2024
| Until 1988 | Studied Landscaping, Technical College, Weihenstephan in Freising,specialisation: 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.