Except Integrated Sustainability
Except Integrated sustainability.
Flourish in a changing world.
Multi-disciplinary consulting, innovation and development organization working on advanced sustainability projects around the globe.

BKCity Slim Refurbishment

Project > Sustainable Renovation of TUDelft's Architecture Faculty

BKCity is a magnificent listed monument of more than 30.000m2 functioning as the faculty of Architecture of the TU Delft. Except created a phased plan to make this historic educational building energy and carbon neutral within ten years.

The plan converts the building into a didactic tool that puts sustainability at the heart of education for generations of architects, introducing a unique in-building ecosystem that provides an inspiring environment, functional qualities and cost savings.

Section of the building showing various ecosystem services. East facing image showing workpods, walkways, greenhouse and ecosystem. The square workpods are movable and stackable. This diagram shows the three phases to energy neutrality. At night the pods are warm bright places in the garden. The Atrium climatizes itself and the building.

The Project:

The BK City Slim Project provided an ideal opportunity to apply Except’s integrated approach to sustainable refurbishment. Except was one of five international teams invited by the Technical University of Delft to design a sustainable vision for their newly relocated architecture faculty after a 2008 fire left the original building in ruins.

The newly chosen building, dubbed BK City, is a historic 1920s labyrinthine brick structure whose contemporary funky furniture and colorful designs belied a much less wallet-friendly energy bill. Except designed a feasible plan and sustainable vision, shared through posters, presentations, and a detailed report.

The Vision:

Our project began from the idea of the building not only as a structure that houses knowledge, but as one that can impart it as well. While focusing on increasing energy efficiency and decreasing operating costs, we also embraced the refurbishment of BK City as an opportunity to increase students’ hands-on experience and understanding of sustainability. We designed the interventions to be participatory, didactic, and engaging, providing students with a 21st century knowledge base they could leverage within and beyond BK City.

BK City is more than a building: it connects the lives of many individuals, functions as a learning platform for generations of architects and urban planners, and acts as the social and functional hub of the disciplines it serves.

This vision informed the central goal of the project: to transform the building into a didactic tool that anticipates and responds to the shifting field of architecture, with an influence that extends beyond its own walls through the actions of those it has educated.

The Approach:

We broke our analysis and approach into the components which we rely on in all our projects to ensure that sustainability is addressed in an integrated manner: Energy & Materials, Ecosystems & Species, Culture & Economy, and Health & Happiness.

In addition to these four thematic streams we also created a phased vision which interweaves easy energy gains and immediate solutions with more ambitious and systemic interventions. Each intervention has cross-cutting benefits, and each phase is designed to build on the one before it, offering an integrated vision for BK City which evolves over time.

The Outcome

The result is a highly didactic building with exemplary environmental quality, an indoor plant ecosystem, more than 10.000 m2 of extra space, energy and water usage that is operationally sustainable, and a plan that is feasible and phase-able (with a total of less than € 25 million invested over 10 years).

Thanks to:

  • Peter Zwinkels (Technokas)

Main Interventions

Energy & Materials Highlights:

  • Wall, roof, window insulation, saves 67% heat
  • “Easy gains”, electrical equipment & lighting, glass embedded PV
  • Compact volume reduces 32% surface exposure
  • South atrium with Fresnel PV, Ground storage
  • Connection to campus bio-gas CHP
  • Space for future energy innovations

Ecosystems & Species Highlights:

  • Pervasive Building Ecosystem
  • Enclosed Atrium Garden, the 'Green Lung’
  • Polyculture & Monoculture Greenhouse
  • Plant-based climatization system
  • Water self-sufficiency and bio-based filtering
  • Green roofs on existing atria

Culture & Economy Highlights:

  • Open-Source, and participatory framework
  • New main entrance, west atrium, pods
  • Collaborative frameworks with Wageningen, Botannical Garden
  • Integrated campus where the technological and ecological meet
  • Long term economic stability

Health & Happiness Highlights:

  • Upgraded heat recapture ventilation system, using exisiting tower as driver
  • Sustainable, healthy, low energy input food system
  • Relaxation & natural zones
  • Bk City Gym
  • Natural Environment: 12% performance gain

Media & Downloads


Except Integrated Sustainability

Tom Bosschaert

Email  [javascript protected email address]
Phone   1107370215


  • Eva Gladek

    Industrial Ecologist
  • Jacob Verhaart

    Head of Science; Industrial Ecologist
  • Stephanie Bartscht

    Marketing and Communications Manager
  • Nels Nelson

    Urban Ecologist
    Except Integrated Sustainability
  • Rebecca Blum

    Except Integrated Sustainability
  • Nico Langeveld

    Except Integrated Sustainability
  • Meredith Davey

    Atelier Ten
  • Stephanie Bartscht

    Communication Design
    Except Integrated Sustainability