Reuse, economics and the uncomfortable work of making nature habitable
The title chosen for the 2026 Oslo Architecture Triennale stayed with me for a few days:
What if Nature Comes First?
Perhaps because the answer initially seems obvious. Of course nature should come first. We have spent decades building as if land, materials and energy were almost unlimited. Moving nature from the edge of the discussion to its starting point feels overdue.
But the longer I thought about the question, the less obvious the answer became.
Which nature are we talking about? And what does putting it first actually require us to do?
The ninth edition of the Triennale, curated by landscape architect Line Ramstad, looks at the question through materials, structures, territories and systems. The programme includes projects using natural and recovered materials, transformations of existing buildings and discussions about ecological economics.
One seminar has a title that kept drawing my attention: How Can We Make Reuse Pay Off?
It is a pragmatic question inside a programme built around a much broader environmental ambition. Perhaps that is why I found it interesting.
Reuse has acquired an almost moral status in architecture, generally for good reasons. Existing buildings contain materials, labour and energy that have already been spent. They may hold memories and relationships with their surroundings that cannot simply be reconstructed. Demolition can erase all this in a few days.
Yet buildings are not interchangeable containers of embodied carbon.
A historic building in the centre of a city, a well-built industrial structure, an empty office block from the 1970s and a contaminated factory are all part of the existing building stock. That does not make them equally valuable or equally capable of supporting another use.
Sometimes the possibility of transformation is already present. The structure is generous, the location still makes sense and the new programme can enter without destroying what gave the building its character.
In other cases, almost every decision reveals another incompatibility. The structural grid may be wrong, the internal height insufficient, access difficult and energy performance extremely poor. Fire safety or daylight requirements can consume much of the usable space. Remediation may cost more than the structure is worth.
Eventually we have to ask whether we are preserving a resource or simply preserving a problem.
I find it difficult to accept the idea that demolition is always evidence of a failure of design. Sometimes the original failure occurred decades earlier, when a building was conceived with no ability to change and no realistic future beyond its first function.
This does not make demolition environmentally neutral. Replacing a building means extracting and transporting materials, producing waste and using energy again. The commercial convenience of starting from an empty site cannot be allowed to hide those costs.
But reuse also needs to survive an honest assessment. How much of the existing building can really be retained? What performance can it achieve? What will the transformation cost, and who will ultimately pay for it?
These questions are often treated with a certain embarrassment in architectural discussions.
Economics tends to enter the conversation late, usually in the role of the person who compromises the design. The environmental idea is developed first; then someone arrives with a budget and begins removing the interesting parts.
That is a familiar story, but it is not the whole story.
A building has to be financed and insured. Someone must operate it, repair it and adapt it again when circumstances change. A material may perform very well in an environmental assessment but require skills or supply chains that do not exist locally. An impressive transformation may still fail if its costs make the resulting spaces inaccessible to the people expected to use them.
Economic feasibility is not an external limit placed on sustainability. It is part of sustainability.
I do not mean that the cheapest proposal is therefore the best one. A low construction price can transfer considerable costs into energy use, maintenance, health or premature replacement. These consequences may appear much later and in someone else’s budget.
Still, if an environmental strategy can only be maintained through permanent exceptional funding, it will remain exceptional. If a community cannot afford to use a building, its material virtues will not be enough to keep it alive.
This is particularly important when we discuss reuse. The real objective cannot be to save the greatest possible percentage of an existing structure at any cost. It should be to understand which intervention creates the most durable value with the resources available.
That answer will not always be the same.
Then there is the word nature itself, which architecture often uses with surprisingly little friction.
In visualisations, nature is usually calm and cooperative. Trees provide shade without blocking the view. Water creates reflections but never floods. Green roofs remain green, apparently without irrigation, maintenance or seasonal change.
It is nature after a very careful selection process.
The less photogenic reality is that nature is also uncomfortable and occasionally dangerous. Rivers overflow, slopes move, vegetation damages structures and temperatures reach levels at which everyday life becomes difficult. Humidity, fire, disease and decay are natural too.
Nature is not cruel. It is simply indifferent to the conditions humans find comfortable.
Architecture exists partly because of that indifference.
We build roofs because rain falls, walls because temperatures change and drainage because water follows gravity rather than our plans. Cities, cultivated landscapes, public parks, canals and managed forests are already forms of transformed nature.
They are a kind of second nature: environments in which natural processes remain present but are modified, limited or redirected to support human life.
I realise that words such as control and domestication can sound uncomfortable today. They recall a period in which human beings believed that rivers, land and climate could be engineered indefinitely without consequence. Many of our current environmental problems come from that confidence.
Complete control was always an illusion.
Abandoning every form of control would be another one.
People expect buildings and cities to protect them. We expect stable ground, clean water, tolerable indoor temperatures and infrastructure that continues to work when conditions become difficult. A hospital cannot simply adapt its activities to extreme heat. A dense city cannot depend entirely on individual behaviour or favourable weather.
Perhaps the more realistic ambition is to understand which natural processes can be accommodated and which risks must still be controlled.
In some places that may mean leaving more space for water instead of continually raising barriers. It can mean using orientation, vegetation and shade before increasing mechanical cooling. It may also require us to accept that certain land should not be developed.
Elsewhere, substantial infrastructure and technology will remain necessary. Context matters more than the purity of the principle.
This is where some versions of sustainable architecture begin to lose me.
Absolute positions are easy to communicate. They are much harder to turn into places where people can live.
Always reuse. Never demolish. Use only natural materials. Remove mechanical systems. Return the land to nature.
Each of these positions contains a valid warning. Applied without judgement, however, they can produce projects that are expensive, uncomfortable or almost impossible to maintain. The result may look convincing at completion and perform very differently a few years later.
People are sometimes treated as the final audience for an environmentally correct solution. The building has already been designed; the community then needs to understand it, accept it and adjust its behaviour accordingly.
Real use is less orderly.
People modify buildings. They replace systems they cannot operate, close ventilation they do not understand and avoid spaces that feel uncomfortable or unsafe. They make decisions based on time, cost and habit, not only on the environmental intentions described by the design team.
This is not necessarily resistance to sustainability. It may be evidence that the project asked too much of its users or failed to explain why a different behaviour was needed.
The most revealing assessment of a sustainable building probably does not happen at its opening. It happens years later, when the original designers are no longer present and the project has entered ordinary life.
Is it still used? Can it be maintained? Did the reused structure support a new function, or did preservation push costs and compromises elsewhere? Have people continued to use the environmental strategy, adapted it intelligently or gradually abandoned it?
These questions are less attractive than a photograph of a newly completed building. They tell us much more.
I return, then, to the question from Oslo.
Perhaps nature comes first in the same way that gravity comes first. Not because it offers a complete design philosophy, but because ignoring it would be absurd.
After that, the difficult decisions remain.
We still have to decide what should be preserved and what can reasonably be replaced. We need to understand how much control is necessary and where adaptation would work better. We have to consider cost without allowing short-term cost to decide everything. Above all, someone will have to use and care for what we build.
This is what I understand by second nature. It is neither untouched wilderness nor a completely engineered environment. It is the imperfect territory humans have always constructed between exposure and protection.
Some buildings will deserve another life. Others will not. Some places should probably be left alone, while others will need careful and continuous intervention.
I do not think there is a single principle capable of resolving these choices in advance.
That may be exactly why the title of the Triennale works. It does not give architecture an answer. It makes the starting point uncomfortable enough to force better questions.