During your study at the faculty of Architecture and the Built Environment you learn to think about solutions for societal issues at an early stage. A good example is the study period of Annemiek Braunius. As a member of the SUM student team, she developed a super-sustainable renovation strategy and built a prototype at The Green Village, the open-air laboratory for sustainable innovation on the TU Delft Campus. With smart solutions to expand the Dutch housing stock and make homes more sustainable, the team devised a way to renew the 847.000 outdated tenement flats in The Netherlands. They rebuilt the prototype in Wuppertal to participate in the biennial Solar Decathlon Europe.

Every day looks different for Master’s student Annemiek Braunius. From making timetables and managing a team of around sixty students to ensuring that deadlines are met and laying foundation beams on the building site. “You learn something from everything. There is no normal day or week. And sometimes it all falls apart,” laughs Braunius. “Those are moments where something else takes priority, and we have to work on that. Building a prototype of super sustainable homes is also a challenge in itself. How do you make something like that efficient?”

Installing foundation beams in Wuppertal: Annemiek Braunius in action on the building site.

SUM strategy: applicable to tenement flats and entire neighbourhoods

Efficiency seems to be the keyword at SUM, or ‘Symbiotic Urban Movement’. The team developed a strategy to transform entire residential neighbourhoods with outdated blocks of flats into sustainable, energy-neutral, inclusive, accessible and diverse neighbourhoods. Braunius: “How does the neighbourhood become better for everyone? That’s the question we set out to answer. We aim to show how these factors can be used together to tackle as many challenges as possible in a relatively inexpensive way.” Team SUM is thus not only committed to winning the Solar Decathlon Europe. In the competition, ten components are assessed, from the quality of the architectural design and energy performance to living comfort and innovative strength. The students of the Delft Dream Team are taking it a step further. They are working with housing corporations, the municipality of The Hague and various suppliers to make a concrete contribution to the challenges of the Dutch housing market. “We have focused on a strategy that can be applied to multiple buildings, just like our predecessors MOR and Prêt-à-Loger. Tenement apartments comprise about 11% of the total Dutch housing stock. That is more than 847.000 dwellings! We can transform these houses in an energy-neutral way with our strategy and add extra living space,” says Braunius.

Additional floors, accessibility and flexibility

The principles of SUM can be applied on building stock throughout Europe. The team proposes to remove the original porches and replace them with wheelchair-friendly galleries. Two additional floors in a lightweight wooden construction make it cost-effective to add lifts to the now often lift-less tenement flats. The facades and the roof will be equipped with solar panels for energy production, the floor plans will be flexible to accommodate different family compositions, and public functions will be introduced on the ground level. “Homes in tenement apartments are often owned by housing corporations, and they often own several apartment buildings in one residential area,” explains Braunius. “If you transform one building, it is difficult to make the strategy profitable. But if you would do this for the whole neighbourhood, it becomes profitable both for the corporation and the people who live there. In the prototype, we show how the different aspects work together.”

The SUM design interventions: the addition of galleries and a lift, public functions on the ground floor and two super sustainable extra layers on top of the existing flat.

A prototype with the newest and smartest technologies

The different perspectives of the multidisciplinary team translate to the breadth of the design and prototype. There are technical aspects, such as the heat recovery in the shower where the hot shower water generates energy. There are practical aspects, such as the sliding walls and folding furniture, to give the floorplans flexibility. “Not everyone knows how sustainable technology works, but most people do know how they would like to live. That is why it is great fun to give tours of the prototype. Then you see people understand the story and saying, gosh, so it is possible to do this with a limited budget,” says Braunius enthusiastically. “I am personally really in favour of not demolishing buildings. We have made a light composite façade using mainly recycled building materials. These are all practical steps towards more sustainable use of both the existing building stock and the material stock. Most techniques are still in their infancy and go beyond standard construction methods. Our partners often visit the prototype to make adjustments and test those.”

The bedroom is incredibly spacious and flexible with foldable furniture. Even the nightstand can be folded away.
By sliding the wall back and forth, the size of the living room is easily adjusted.

The emergence of a multidisciplinary student team

The design interventions of SUM did not appear out of thin air. The enthusiasm of the large team is the driving force behind the strategy. How did Braunius become a part of this group? “After completing my BSc in Architecture, Urbanism and Building Sciences, I wanted to do something different,” she remembers. She hesitated between the Architecture and Management in the Built Environment master’s tracks and decided to apply for SUM with MOR’s work in mind. She started out with a small team of seven students and started looking for more people to expand the team after the summer of 2019. What was supposed to be a two-year project became a three-year project through Covid-19. “We started as a group of students with visions of the future and revolutionary plans, but through the conversations with partners, we also started thinking about the cost and origin of our building materials. The practical side is very interesting and so much more important than I expected. Our team has also expanded to include students from many more faculties at TU Delft: Civil Engineering and Geosciences, Electrical Engineering, Mathematics and Computer Science, and Technology, Policy and Management.”

The SUM team and the prototype at The Green Village in Delft.

Suddenly building your own house

The SUM team devised its own team structure, in which everyone is equal. Braunius: “It was important to find our way in this. Consulting with thirty people at once is not practical if you have to make decisions quickly.” Representatives from the various design committees and supporting committees are members of the so-called project board, which meets on Mondays to make decisions and plans for the coming week. “We are continuously confronted with the facts. We started as a group of people innocently thinking about team colour. In the pressure cooker of the project, we became a full-fledged company with costs. Partners take you seriously very quickly, even though you have not even graduated yet. And then, just like that, you have built your own house with, by now, a group of friends. It sounds like a big group, 58, but we can honestly not do without any of them.”

All team members are essential on the building site.

Learning by doing

Everyone works on different tasks on the SUM construction site, often without prior theoretical knowledge. “Practical experience helps to learn how things work. The Architecture, Urbanism and Buildings Sciences degree gives you a lot of freedom, but I think it’s good to know how others deal with your design. Some things you simply can’t build. The study programme sometimes lacks such a reality check.” The team again faces this challenge in Wuppertal. In a mere 14 days, SUM rebuilds the entire prototype. “We look forward to seeing the other teams. We feel our project addresses all themes the judges will assess, but it’s exciting to see how we will do in the competition itself.”

In a mere 14 days, SUM rebuilds the entire prototype in Wuppertal. The students work in shifts from 7 AM to 3 PM and from 3 PM to 11 PM.

The next step

And what will she do after Wuppertal? “I would really like to know, but I am really bad at making choices. I’m going to finish my MSc in Architecture, and then I will stay in the field of architecture and the built environment,” muses Braunius. “I want to keep working within the existing building sector. You don’t necessarily have to make the most beautiful or newest design. If you can transform something, so it suddenly becomes a home, or people can do those reconstruction jobs themselves... There are so many empty buildings! To ensure that existing buildings can be transformed and change function with the times. That is the future.” 

After its unveiling on 11 March 2022, SUM's prototype was on display at The Green Village in Delft. The completely demountable structure was then moved to Germany to take part in the competition, where SUM managed to secure 3rd place. Previous TU Delft entries to the Solar Decathlon Challenge, MOR and Pret a Loger, can still be seen at The Green Village. After the competition, Annemiek Braunius, Kelvin Saunders, and Nando Versteeg founded SUM+, an advisory body that puts the gained knowledge from the research project into practice. They are currently engaged in inspiring property developers, housing associations, municipalities, and governments with their story. They also publish advice and perform feasibility studies on the transformation and uplift process. Finally, they are developing an interactive map that quickly shows whether buildings are suitable for a ‘top up’.

This story is published in May 2022 and updated in October 2023.

More information

Check the SUM project website for more information.

SUM was supported by Professor Mauro Overend (Structural Design & Mechanics, AE&T), Professor Andy van den Dobbelsteen (Climate Design & Sustainability, AE&T Department), Professor Hans Wamelink (Design & Construction Management, MBE Department), Professor Ulrich Knaack (Design of Construction, AE&T Department), and Peter de Jong (MBE Department).

Header image: Image by SUM