Drees & Sommer

Drees & Sommer is an international consulting, engineering and project-management firm focused on the construction, real-estate and infrastructure sectors. Headquartered in Stuttgart, Germany, it supports clients across the life cycle of complex assets: from initial feasibility and development through planning, procurement, construction, commissioning, operation, optimization and potential revitalization. Its work covers building construction and infrastructure projects of many types and scales and extends across sectors including transportation, industry, pharmaceuticals, commercial property and public development. The firm's principal activities include development and process consulting, infrastructure consulting, project management, engineering and real-estate consulting. It also advises clients on green building, sustainable development, the optimization of existing buildings and cradle-to-cradle approaches. These services can include sustainability strategy, certification support and guidance for internationally recognized green-building labels. Digital and delivery capabilities include Building Information Modeling and Lean Construction Management, which are used to coordinate complex projects, improve transparency and manage interfaces among stakeholders. Drees & Sommer developed from a Stuttgart engineering office founded in 1970 by Gerhard Drees, a professor at the University of Stuttgart, and Volker Kuhne. The original practice worked in network technology, production planning, operational organization and construction consulting. Hans Sommer joined as a partner in 1973, after which the business adopted the Drees & Sommer name. During the following decades, the firm expanded its workforce and geographic presence and introduced a partner model in the early 1980s. Under that model, individual operating companies could organize themselves with considerable independence while accommodating growth across locations and employee groups. A major corporate consolidation followed in 1991 with the creation of Drees & Sommer Aktiengesellschaft, which brought the previously separate companies under a common umbrella. Gerhard Drees became chairman of the supervisory board and Hans Sommer became chairman of the executive board. The organization was converted into the European company Drees & Sommer SE in 2017. The SE remains partner-managed and is not publicly listed; its shares are held by active and former managers rather than outside public investors. Operating locations function as independent units under the group structure. The firm has been involved in major projects including Potsdamer Platz in Berlin, Messe Stuttgart and Building 1 for the F. Hoffmann-La Roche pharmaceutical group in Basel, completed in 2015. It also took part in the early development of Stuttgart 21, preparing the feasibility study, managing preliminary project work and initially holding a minority stake in the project company DBProjekt GmbH Stuttgart 21. That stake was sold in 2001. Today Drees & Sommer positions itself as an independent professional-services partner combining technical expertise, management consulting, sustainability knowledge and digital project methods. Its partner ownership is intended to support independence from external corporate owners, while its service model allows it to engage across the full life cycle of building, infrastructure and real-estate portfolios.

Drees & Sommer traces its origins to 1970, when Gerhard Drees, a professor at the University of Stuttgart, and Volker Kuhne established an engineering office in Stuttgart under the name Drees, Kuhne u. Partner. The practice initially concentrated on network technology, production planning, operational organization and construction consulting. Its early profile therefore combined technical engineering with organizational and process-oriented advice rather than focusing solely on architectural design or construction execution. Hans Sommer joined the business as a partner in 1973. The firm subsequently adopted the Drees & Sommer name and began a long period of expansion in employees, locations and service scope. As the organization grew during the early 1980s, it adopted a partner model. Separate companies were established for defined groups of employees and locations, allowing operating units to act with independence while remaining connected through shared ownership and the broader Drees & Sommer identity. This structure became an important part of the firm's later governance model. Drees & Sommer Aktiengesellschaft was established in 1991, bringing the individual companies together under one corporate umbrella. Gerhard Drees became chairman of the supervisory board, while Hans Sommer became chairman of the executive board. The consolidated organization expanded from engineering and construction advice into broader project management, process consulting, infrastructure consulting and real-estate services. This development positioned the firm to support projects across their full life cycle, from feasibility and development to implementation, operation and renewal. One significant assignment was Stuttgart 21, the major rail and urban-development project. Drees & Sommer prepared the feasibility study, managed preliminary project activities and was initially involved as a shareholder in DBProjekt GmbH Stuttgart 21, the project company. The firm held a 10 percent interest from 1996 and sold it on 1 August 2001. The Stuttgart 21 work illustrates the company's involvement not only as a technical consultant but also in complex program development and project organization. The firm's portfolio later included major developments such as Potsdamer Platz in Berlin, Messe Stuttgart and Building 1 for the F. Hoffmann-La Roche pharmaceutical group in Basel. The Basel building was completed in 2015. Alongside traditional project and engineering management, Drees & Sommer broadened its capabilities in sustainability and digital construction. Its green-building activities include sustainable development, existing-building optimization, cradle-to-cradle concepts, certification advice and support for international green-building labels. Building Information Modeling and Lean Construction Management became tools for coordinating large and technically complicated programs. In 2017, Drees & Sommer AG was converted into Drees & Sommer SE, a European company. The organization remained private and partner-managed, with shares held by active or former managers who had made a substantial contribution to the business. Its locations operate as independent units beneath the SE umbrella, while the management board is drawn from active partners. Hans Sommer later served as chairman of the supervisory board before Johannes Fritz succeeded him at the beginning of 2023. The management board identified in the reference material comprises partners Dierk Mutschler, Steffen Szeidl and Marc Schömbs. The firm marked its fiftieth anniversary in 2020. In its current form, Drees & Sommer combines engineering, management consulting, sustainability expertise, real-estate advisory and digital project methods. Its defining characteristics are independence from external listed-company ownership, partner participation, multidisciplinary delivery and involvement in complex building and infrastructure projects from early concept through operation and possible revitalization.

• 2023

  Change in supervisory-board leadership

  [1]Drees & Sommeren.wikipedia.org

  Johannes Fritz became chairman of the supervisory board, succeeding Hans Sommer.

• 2020

  Fiftieth anniversary

  [1]Drees & Sommeren.wikipedia.org

  Drees & Sommer celebrated 50 years since the founding of its original Stuttgart engineering office.

• 2017

  Conversion into Drees & Sommer SE

  [1]Drees & Sommeren.wikipedia.org

  Drees & Sommer AG was converted into a European company, or SE, preserving the partner-managed structure.

• 2015

  Completion of Building 1 for F. Hoffmann-La Roche

  [1]Drees & Sommeren.wikipedia.org

  Building 1 of the F. Hoffmann-La Roche pharmaceutical group in Basel, identified as one of the firm's major projects, was completed.

• 2001

  Stuttgart 21 stake sold

  [1]Drees & Sommeren.wikipedia.org

  The company sold its 10 percent interest in the Stuttgart 21 project company on 1 August 2001.

• 1996

  Investment in the Stuttgart 21 project company

  [1]Drees & Sommeren.wikipedia.org

  Drees & Sommer held a 10 percent stake in DBProjekt GmbH Stuttgart 21 while supporting the project's development and preliminary work.

• 1991

  Drees & Sommer Aktiengesellschaft established

  [1]Drees & Sommeren.wikipedia.org

  Drees & Sommer AG was formed to unite the previously separate companies under a common corporate structure.

• 1980

  Partner model introduced

  [1]Drees & Sommeren.wikipedia.org

  During the early 1980s, the expanding business organized itself through a partner model and independently operated companies serving defined groups of employees and locations.

• 1973

  Hans Sommer joined as a partner

  [1]Drees & Sommeren.wikipedia.org

  Hans Sommer became a partner, and the practice soon adopted the Drees & Sommer name.

• 1970

  Founding of the Stuttgart engineering office

  [1]Drees & Sommeren.wikipedia.org

  Gerhard Drees and Volker Kuhne founded Drees, Kuhne u. Partner in Stuttgart, initially focusing on network technology, production planning, operational organization and construction consulting.

Independent, partner-owned, multidisciplinary professional services focused on complex construction, real-estate and infrastructure projects, with an emphasis on sustainability, life-cycle value and digital delivery methods.

• Professional services

  Project and program management

  Drees & Sommer manages building and infrastructure programs from early feasibility and development through planning, implementation, operation and possible revitalization. The service is aimed at complex projects involving numerous technical, commercial and public-sector interfaces, with emphasis on coordination, schedule and process control.

• Engineering services

  Engineering and construction consulting

  The firm provides engineering and construction advice for projects of different types and sizes. Its work builds on the original practice's technical consulting heritage and is integrated with project management, process consulting and implementation support rather than being limited to a single design discipline.

• Infrastructure services

  Infrastructure consulting

  Infrastructure consulting covers the development and delivery of major infrastructure programs, including complex projects requiring feasibility assessment, preliminary planning, stakeholder coordination and structured implementation. The firm's Stuttgart 21 involvement is an example of this broader project-development capability.

• Real-estate advisory

  Real-estate consulting

  Real-estate services address development, portfolio and asset-related questions across the life cycle of buildings and property programs. They are combined with technical, organizational and sustainability advice so that clients can assess not only development potential but also operation, optimization and long-term value.

• Sustainability services

  Green-building and sustainability consulting

  Drees & Sommer advises on green building, green development, sustainable construction, existing-building optimization and cradle-to-cradle approaches. The offering can extend from sustainability strategy and technical consulting to certification and support for international green-building labels.

• Digital engineering services

  Digital construction and delivery services

  The firm uses methods such as Building Information Modeling and Lean Construction Management to support large and complex projects. These approaches help structure project information, coordinate participants and improve construction processes across planning and delivery.

• 2017

  Conversion to a European companyStrategy

  Background

  Drees & Sommer continued to operate as a private, partner-owned international firm with multiple operating locations.

  Action taken

  Drees & Sommer AG was converted into Drees & Sommer SE.

  Aftermath

  The SE structure retained partner ownership and the umbrella relationship among independently organized operating units.

  Source

• 1996

  Participation in the Stuttgart 21 project companyOther

  Background

  Drees & Sommer had prepared the Stuttgart 21 feasibility study and handled preliminary project work.

  Action taken

  The firm held a 10 percent stake in DBProjekt GmbH Stuttgart 21 while continuing its project-related involvement.

  Aftermath

  The stake was sold on 1 August 2001, while the Stuttgart 21 engagement remained an important example of the firm's infrastructure and program-management work.

  Equity stake. 0% (1996 to 1 August 2001)

  Source

• 1991

  Creation of Drees & Sommer AktiengesellschaftStrategy

  Background

  The partner-based operating companies had grown and required a shared corporate structure.

  Action taken

  Drees & Sommer Aktiengesellschaft was established to bring the individual companies together under one roof.

  Aftermath

  The consolidated structure provided a common platform for the firm's expanding consulting, engineering and project-management activities.

  Source

• 1980

  Adoption of the partner modelStrategy

  Background

  The company was expanding in employees and locations and needed an organizational structure that could accommodate multiple operating units.

  Action taken

  Drees & Sommer organized its growing activities through a partner model and independently operated companies serving defined groups of employees and locations.

  Aftermath

  The model became a continuing feature of the firm's ownership and governance approach and supported later expansion under a common group umbrella.

  Source

1. 1Drees & Sommeren.wikipedia.org
2. 2Drees & Sommer official websitedrees-sommer.com