Today we discuss the whole energy life cycle of a home and how, perhaps in the future, we should consider a ‘carbon-wallet’ for our lives, which includes where we live and its own carbon costs.
"Build nothing, build less, build efficiently, build with less impact"
Architects have to think of many things. Resource-efficient designs will help reduce the need for new construction and demolition. In a world facing resource scarcity, the way in which materials are sourced and buildings are constructed must change.
My guests are architects Carine Oberweis and Philippe Nathan, civil engineer Lee Frank and Paul Baustert, policy maker and Attaché at the Ministry of the Economy in Luxembourg.
Carine is passionate about creating healthy living spaces with low-energy design. Having spent many years working in Ghana (and being the Honorary Consul of the Republic of Ghana in Luxembourg), Carine also works on developing new building products made from waste material. This is an industry with huge future potential.
Lee Franck works with the construction industry, currently responsible for about 40% of carbon emissions, to devise low carbon designs.
Architect Philippe Nathan has worked on The ‘Grande Porte des Alpes’ in Lyon, developing a vision of a decarbonised and resilient region by 2050.
As Attaché at the Ministry of the Economy in Luxembourg, Paul Baustert works on preparing legislation related to the whole life carbon of buildings.
Where does carbon reside in our homes?
This is not as obvious as it may seem. Every bit of material that makes our home has an energy cost to it, which is why it is not always the most energy efficient decision to demolish and build again.
We are all very aware of energy consumption when it comes to heating, ventilation and electricity, not least because this is an on-going (and likely increasing) cost. However, we are less conscious of the ‘stuff’ that our buildings are made of. This is grey energy.
For so long the conversation on reducing energy consumption has circled around insulation, energy efficient windows, machines to vent the house mechanically, but not the overall carbon dioxide savings.
We are now moving to a ‘whole-life’ carbon approach, and new legislation is on its way to take into account the impact of the materials that go into construction. From 2028 onwards, for a new building to be permitted, it needs to have its carbon footprint calculated over its life-time, energy consumption and carbon in the materials to build it. From 2030, limits on how much carbon can go into a building will come into place.
An average size house in Luxembourg has a carbon footprint of roughly 200t CO2 in the materials. That’s about 100 return flights to the United States. If we reduce the carbon footprint of our house by 20%, we save the equivalent of about 20 return flights or the offset of an average person in Luxembourg’s carbon footprint over 2 years (an average person’s carbon footprint in Luxembourg is 18t/annum)! And if we scale this up to a global scale – we could build one city like Paris each week in energy savings.
How can we change this situation fast?
Lee Franck has a few suggestions here:
- Build Nothing: do we need to build more? Could we convert existing buildings? Stop demolishing! “Demolishing and building something new which claims to be “green” is greenwashing.”
- Build Less: what is enough?
- Reuse materials: start the mindset of urban mining. All existing buildings are material banks. We need better data management systems to log this however.
- La frugalité heureuse: what are our fundamental needs to be happy? For example, cellars are highly carbon intensive to build. Can we use one space in multiple ways.
- Logistics: how to transfer one component from an old to a new building.
- Leave things ‘unfinished’ (exposed ceilings and floors etc.)
- Build efficiently: use fewer resources for the same needs
- Carbon footprint calculation and set goals on how much carbon should be used
- Build with timber. There is a common misconception that building in timber has a negative carbon impact. Global demand for timber is predicted to quadruple by 2050 and although at least in Europe forests are growing, this demand cannot be met and these monoculture plantations come with a loss in health of the forests and biodiversity and illegal sourcing.
- Innovation for better materials and products.
What is the role of an architect in our society?
Architects play a unique role in society, enhancing lives by thoughtfully considering how people live, work, and shape their environments. In today’s fast-paced world, homes should offer a sense of calm and grounding.
Carine believes in creating a home which has a soothing effect on the human senses, through careful consideration of volume, colour, touch, acoustics, and even scent. Architects and engineers also have to design for communities, to encourage human interaction whilst ensuring privacy and reducing isolation.
Carine’s work in Ghana develops her passion for empowering local communities and promoting social equity.
“In response to global challenges such as the climate crisis, demographic changes, economic instability, and disrupted supply chains, the focus is on finding innovative, sustainable solutions - local solutions to local problems.”
Collaborative efforts in West Africa have led to the development of new building materials from waste, with plans to apply this knowledge to projects in Luxembourg. Carine’s vision aligns with the philosophy of "build nothing, build less, build more clever, build with less impact." She encourages us to value what already exists, appreciating imperfections both in life and in the built environment.
“It's about embracing nature-based materials, minimising transformations, and reducing both embodied and operational energy. For example the Gulf of Guinea may seem distant, the ripple effects of its developments will touch us all. Global well-being is a shared responsibility, shaped by the daily decisions we make. Every choice has global consequences, underscoring the interconnectedness of our world and the urgent need for sustainable, responsible practices.”
Paul has the unenviable task of thinking about the whole building ecosystem with associated environmental challenges in order to put together a framework of policy decisions that will help the country for generations to come.
Carbon Budget
As a final thought, Carine Oberweis has a suggestion for us to consider as we move towards the New Year - what is your carbon budget?
“To grasp the importance of global well-being, we must recognise it as a shared responsibility - one shaped by our everyday decisions. Each choice we make has a compounding effect on the world, emphasising our global interdependence and the urgent need for sustainable, mindful practices. Imagine it like a monthly budget, with a limited "carbon wallet" for spending. With each choice, your carbon budget gets smaller, and by the month’s end, we hope you've managed to keep enough for future flexibility. Let's start thinking of each decision as an investment in the world of tomorrow, striving to make each choice one that preserves our collective resources for the long term. What’s your carbon budget for 2025 ?”
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