‘The most sustainable building is the one you don’t build’

What if everyone who attended Batibouw, Belgium’s largest construction fair which will draw tens of thousands of aspiring builders to De Heizel, decided not to build? It sounds like a joke, but architects Tim Vekemans and Dimitri Minten of RE-ST have turned not-building into their business model. ‘Sixty percent of our residential buildings is underutilised. It’s time we asked ourselves what we can do about this.’

Sue Somers, De Morgen, 18-02-2017

Article published in De Morgen on 18/02/2017


The RE-ST architects are headquartered in Antwerp's station district. As one might expect, they did not build the office they work in and they share it with other companies. But not for long: the firm is currently looking to relocate, ideally to a church. According to Tim Vekemans, there are 1,860 parish churches in Flanders, many of which lie permanently vacant. It’s quite the challenge.

Vekemans and his business partner Dimitri Minten have made it their mission to convince building owners to use their space as efficiently as possible and make any extra or unused space available to others. ‘Architects always address a spatial need with a building,’ says Minten. ‘We realised that most people come to us with a spatial need or request. But we don’t believe building is always the answer. Before you start building, you first have to determine whether not-building is an option.’

Not-building sounds like a provocation and comes across as somewhat counter-intuitive.

Minten: ‘The concept actually isn't new at all: architect and artist Luc Deleu spoke of not-building as early as the 1970s, when the construction sector was booming in our country. Yet a lot of people still struggle with the idea.’ ‘The first few meetings with an architect usually focus on the percentage he or she gets for designing the building. What we’re interested in discussing first are our client’s spatial needs. The most sustainable building is the one you don’t build.’

As an architect, how can you make a living by not-building?

Vekemans: ‘It’s not that our firm never builds.’ ‘If the need to build is justified, we’ll build. We do a lot of housing projects because there's a real need for high-quality collective housing. This is an urgent issue and therefore extremely relevant.’ Minten: ‘Some of the tactics of not-building include restoration, renovation, and repurposing. There are plenty of ways to breathe new life into existing heritage.’

That goes against the dream of most Belgians to build their own home. What you're suggesting requires a completely different mindset.

Minten: ‘The dream to build was the result of a mind shift in the sixties and seventies. After the Second World War there was a major housing shortage. Home ownership was therefore encouraged and land was made available to the masses so that everyone could build their own houses. Today's housing market reflects this legacy. We have a massive building stock. The Flemish Government Architect estimated that we could house seventeen million people in the buildings currently available in Flanders.’ Vekemans: ‘Not-building is part of the sustainability debate. In Flanders we live scattered and our houses are far apart. The result is traffic congestion, declining biodiversity, and poorer air quality.’

Speaking of sustainability: you want to take the building freeze proposed by the Flemish government one step further and halt all construction work.

Vekemans: ‘Building freeze might be the wrong word. What we want is a land freeze – the agreement is to not occupy any new land as of 2040. A building stop means not adding any more cubic metres until we've struck a better spatial balance. More than sixty per cent of our residential buildings is underutilised, which comes down to two or more extra bedrooms. Everyone understands what vacancy means, but the concept of underutilisation is rarely discussed. We need a clearer overview, a kind of spatial radiography, to identify the space we currently have and how best to use it.’

You’ve come up with a word for our failure to understand our use of space: wanderspace.

Vekemans: ‘Before we can talk about underutilisation, we need to understand the figures. There are vacancy maps, but no maps that show how spaces are being underutilised. Identifying wanderspace is no easy task. It’s about our property, after all. An SME in a large business complex may not feel the need to share its space with fellow entrepreneurs, even though it could generate additional income. In many cases, we simply don't think about it or aren't aware of it. A Flemish family with two extra bedrooms: who cares?’

How do you highlight underutilised space?

Vekemans: ‘By closely examining how people use a building. In Hoogstraten we’re busy restoring the Klein Seminarie. Initially, the school had planned to have a new building constructed. Based on our research, however, we realised there was plenty of underutilised space in the school. They had gone from housing 400 boarding students to 150, meaning the infrastructure no longer suited the needs. The school also has one of the largest playgrounds in Flanders, while the municipality of Hoogstraten doesn’t even have a public square. If we want community schools, we should think about converting existing playgrounds into communal squares and vice versa.’

Minten: ‘The school also had a chapel that was rarely used. Hoogstraten is a municipality without a cultural centre. Unfortunately, there wasn’t enough money to restore the chapel, so we brought the city and the school together and asked them to think about how they could both use the chapel. We'd organised a project week in the chapel to prove that this was possible. We’d also hung up an activity sign-up sheet in the teachers’ lounge. The chapel was used intensively that week: there was a capoeira workshop, a lie-down concert, a play afternoon, lessons, seminars, and even a fashion show. The students and teachers suddenly realised how versatile the space was. The city may not have a cultural centre, but it did gain a new location for cultural activities. This creates new opportunities for the future.’

Vekemans: ‘It’s a great story that helps to raise awareness. They suddenly found themselves not-building. Figures can help reinforce this, as we recently proved with architecture students from UHasselt, where Dimitri and I teach. For one month, we analysed the use of classroom space in a specific wing of the university compared to the applicable timetables. All 205 classrooms were red, meaning they were in use less than thirty per cent of the time.’ Minten: ‘When we design a new school, we have to ensure that eighty percent of the classrooms are always in use. In some of our universities, the classrooms are empty seventy percent of the time, which means that instead of being used forty hours a week, they're barely used twelve hours.’

Vekemans: Most people think there’s a lack of space, including at schools. The reality is that they have no idea how the space is being used. Many rectors probably hear there's a shortage of classrooms on a weekly basis. Studies like ours on underutilisation can be very confrontational and can help us make better use of the available space. The reality is that we have too much space.’

Hence your call for space-neutral building from now on. What exactly does this mean? Minten: ‘It means only adding new cubic metres if you remove some elsewhere. It’s all about finding a balance. In Europe, buildings have a lifespan of about seventy years, after which they need to be replaced. It’s important to think carefully about which buildings we want to replace. Some buildings aren’t in the right location. Perhaps it’s time to relocate them to low-traffic areas or near railway stations.’ Vekemans: ‘Demolition is another aspect of not-building. Some buildings simply aren’t worth investing in and should be levelled. Therein lies an even bigger challenge: what do we keep and what do we scrap?’

You've also proposed a surplus tax. How do you see this being implemented in real life? Should people be asked to submit a family plan along with their building permit application to justify the number of bedrooms they have?

Minten: ‘We want people to start thinking about the space they occupy. The question is whether the government should stimulate this or penalise it in the form of taxation. We're already being taxed for our 'excesses’ without even realising it. The cost of our fragmented way of living and working is added to different cost centres, such as road maintenance, mobility costs, energy costs, etc.’

Vekemans: ‘We think it's better to reward people for sharing underutilised space. This can also generate additional income that can be invested in making existing buildings more sustainable.’

Demolishing or relocating buildings to make more space would mean taking away people’s property. I don't think most people would be too happy about that.

Minten: ‘It's taboo, we realise this. Land ownership is sacred to a Flemish person. Most of us own property, myself included, and we all want housing security. But at some point we’ll have to question our ownership structure.’

Vekemans: ‘Ownership as an investment model is fragile. These days, there's no guarantee that property will by definition have added financial value. Large houses and detached houses will become increasingly difficult to sell to future generations. Just look at the family villa owned by former football player Jean Marie Pfaff. Add to that the fact that less than fifteen per cent of young couples can afford a new-build home. This isn’t surprising given that a building plot costs between 150,000 and 200,000 euros and house prices have increased from 250,000 to 400,000 euros. How many double-income households can afford this and are willing to invest in a thirty-year mortgage? We’re guessing that future generations won’t want to be saddled with the burden of a mortgage. The entire concept is becoming outdated.’

So property ownership will become obsolete in the future?

Minten: ‘We’ll have to come up with different structures. Instead of investing in bricks and mortar, our home security will come in the form of shares in housing cooperatives. We’ll start by buying shares in a student room. In the next life phase, when we need more space to accommodate a partner or children, we’ll use our shares and our savings to buy a bigger home. Then, following a divorce or after the children have left home, we may choose to downsize again. In the final phase of life, we may choose to move to a serviced apartment – all within the same housing cooperative. This system already exists in Switzerland, Austria, and Germany.’ Vekemans: ‘The future is also about affordable living. This means living smaller and closer to a city centre.’

This discussion seems to apply to one specific group: people in rural areas. It sounds like they will be forced into cities more or less against their will. Vekemans: ‘That's not the case at all.’ According to the Flemish Government Architect, we should all move to cities and urban centres. ‘Detached buildings are a crime.’ Climate experts are calling for residential towers, even in villages, as a kind of landmark. Do you foresee us all living in apartments in the future?

Vekemans: ‘No. The Government Architect is in favour of more densely populated areas, which can also be achieved with terraced housing. Today’s housing market does not offer enough high-quality, affordable terraced houses, despite these being preferred by most Flemish people.’ Minten: ‘The classic subdivisions of the sixties and seventies consist of fifteen to twenty homes per hectare. You can improve quality by building thirty to thirty-five homes per hectare without having to go up four or five storeys.’ Vekemans: ‘There are many subdivisions on the outskirts of the city that are close to public transport and other facilities, which are suitable for densification. You can add units by removing two or three storeys and replacing them with five or six houses.’

What about the rural parishes? Should we just let them empty out?

Vekemans: ‘They already are. People no longer see it as the ideal place to live. There are no shops, no daycare centres, and no gyms or sports centres. Vito created a junction map which reveals a number of parishes that will simply disappear next century because of their location.’ Minten: ‘The question is whether we should let this happen and just leave them to their fate or support and speed up the process to make things easier.’

Based on a 2018 reader survey conducted by the journal Ik ga bouwen (About to build), 48% of people currently live or want to live in a detached home. Most people who move are looking for a house with a garden, preferably one bordering a nature reserve or a watercourse. People still want to live near nature.

Vekemans: ‘And they can. But we’ll have to become more critical of where we can accommodate these housing preferences. Houses will have to become more compact – as in fewer detached houses on ten-acre plots – because the ecological footprint is just too big. We need to make Flemish people understand that refusing to think about the location will waste a lot of money. We can't guarantee public transport everywhere and we can't keep building more and more roads.’

Minten: ‘On the other hand, the government has to commit to create higher quality public spaces, as they will ultimately determine the quality of the nearby homes. If there are enough parks, playgrounds, parking areas, shops, schools, and bakeries, the quality of life will be better. These facilities are either closing down or becoming run-down. People reason that if the government doesn't provide parks or high-quality public spaces, they’ll just have to create them in their own back gardens. The question is what do we want to invest in: roads or parks? Do we invest money in the people who maintain our parks and landscapes, or the people who maintain our roads? This is the choice we're faced with today.’

What about the quintessential Flemish ribbon developments?

Minten: ‘If you look at the Ferraris map of Flanders from the eighteenth century, you’ll see we already had a ribbon network between different villages at that time. In addition to these historic ribbons, we have ribbons from the sixties and seventies, which came about unintentionally. Our job is to determine which ribbons to keep. In most cases, it’s the ones on the Ferraris map. We need to strengthen these and cut or even ‘unravel’ others.’ Vekemans: ‘Stopping this ribbon-making history sounds logical, but it's not. At the beginning of the last century, Flanders introduced the afwerkingsregel (completion regulation), which made it possible to finish provisional façades, or the undeveloped side of a building. In other words, we can build a house on that side, regardless of whether it's located in a residential area. Many of these provisional façades can be found near ribbons, whereby the regulation is actually stimulating ribbon development.’ ‘Ribbon developments are outdated. We shouldn't be building houses that require a car. In fact, we should get rid of the completion regulation entirely. This is easier said than done: if there’s a 150,000-euro plot of land sitting next to a house, it’ll suddenly be worth nothing.’

Will people be compensated for this?

Vekemans: ‘If you lower the land value by deciding not to build in certain places, you need to compensate people. This money can come from places with more development rights.’ ‘Here's the thing: if we keep building like are now, we’ll get bogged down. We're building too much without thinking of the consequences. We assume that the materials we need to build are somehow infinite, but they're not. We don't realise that our existing building stock in Flanders is our most valuable resource. We can't keep producing new buildings without a care in the world. What we want to do is encourage reflection. This isn't a plea for a building freeze, it's a plea to hit the reset button.’

Minten: ‘Our not-building philosophy is not aimed at the construction economy. We need this economy now and in the future to replace or relocate certain buildings and to renovate others. The construction industry will have to reinvent itself over the next twenty or thirty years – just like we try to do every day.’