Ask Mario Cucinella to talk about Net Zero buildings. And discover that, when talking about sustainability, it is better to be cautious and realistic

When we talk about Net Zero architecture the risk is to imagine that the path taken will lead us directly to live in garden cities, surrounded by trees and parks and populated by ecologically intact buildings, white as doves.

Mario Cucinella, a career dedicated almost entirely to low impact design, he warns us. And he invites us to reflect on the voracity of production dynamics with a realistic immersion in the reality of the climate crisis.

“My doubt is that we are constantly looking for alibis, not real solutions,” comments the architect. “Design practice is focused on low-impact architecture, but there are gray areas over which we have no control. We are giving ourselves rules, we have intentions that are increasingly supported by European laws on construction. But the general picture is not resolved and is unlikely to be resolved in the near future if we do not realistically address the climate crisis with collective political choices".

What does it mean to look at the climate crisis through data to get a realistic idea of it?

Mario Cucinella: “There are two levels of analysis. The first is of a human order. Cultivating a happy coexistence between nature and the city makes a lot of sense.

It is a path that is part of our cultural and planning maturity and there are parameters that demonstrate its usefulness. When you ask people what are the fundamental aspects for creating well-being inside a building, the answer is invariably the air quality and the light natural.

State of mind and creativity benefit in a directly proportional way from proximity to the environment. And this is a very important part of the whole, which is increasingly taken into account even in certification".

But isn't this the solution to tackling the climate crisis?

Mario Cucinella: “The broad vision concerns pollution, the real problem. In Italy we produce 450 million tonnes of CO2 per year. We have enough trees to absorb 50 million tons.

And even if we decided to replant enough trees to absorb, say, 400 million tons, we wouldn't be able to do it, because there isn't the space.

Of course I think any step in the right direction, no matter how small, is helpful. But we just can't ask nature to solve a problem that we keep creating. We need to ask ourselves: what are we willing to give up?

It therefore seems like a collective, political problem. The latest Cop28 in Dubai confirms this. But let's proceed in small steps: what is a net zero building and why isn't it enough?

Mario Cucinella: “Net zero is a definition I am skeptical about. What does this mean exactly? That we build buildings that consume very little energy because they are designed not to be flooded with light and heat, or cold during the winter.

Operations are powered by renewable sources. In this case I'm talking about NZEB (Nearly Zero Energy Building).

An 'almost zero' that significantly improves the ecological impact thanks to a project that defines its quality in the energy result. It's a point that often escapes.

Today we are able to achieve very low consumption, around 7 KwH per square meter per year. To better understand this result, it is enough to say that fifteen years ago we were around 250 KwH per square meter".

What is the fundamental measure for designing a Nearly Zero Energy Building?

Mario Cucinella: “Architecture, the way of designing, the materials are all substantial factors. The objective is to isolate the space from unnecessary temperature changes.

A building is climatically responsive when it provides effective protection from extreme weather conditions, while exploiting environmental resources to support its operations.

The opacity of the surface must reach 70%: we have said goodbye to large glass surfaces and recent architecture has a completely different appearance.

It is a choice that conditions aesthetics but which cannot be limited to the technical exercise, otherwise the space becomes unlivable. In LEED certifications and other more recent ones there is an important evolution: human parameters and the well-being of the people who use the space are taken into account. The center of the debate has evolved towards different criteria."

A successful MCA project from the point of view of environmental impact?

Mario Cucinella: "The project for the new University Center of Aosta is a good example of how it is possible to imagine a contemporary architecture that cooperates in a functional way with the landscape and with the climate.

Colors and characteristics create a link with the snowy alpine landscape, departing from the rigidity of the pre-existing Caserma Testafochi.

On the other hand, they generate a form that guarantees energy performance with the aim of making it one of the first Italian NZEB public buildings.

Is it therefore a delicate balance between human well-being and low energy impact design?

Mario Cucinella: “The quality parameters take both into account. However, there remains an area that is difficult to investigate and concerns other CO2 costs: the production and transport of materials, logistics, construction site operations, maintenance.

These are difficult to measure data and, as regards materials, we are still far from having clear numbers. Any human activity produces a carbon footprint.

I believe it is important to be careful not to find alibis, such as compensation. It may be that despite the attempt to remedy our CO2 production in Milan, Brazil can breathe better because we plant a few square kilometers of forest. Here, however, we will continue to live in a polluted place."