Ecological renovation according to Le nouveau printemps

Rénovation d’une maison ancienne

Making an ecological renovation was above all doing a normal renovation but with bio-based materials. The goal is to save energy and water. As a result, here is a non-exhaustive list of the elements considered in the initial project:

 

  • Replace the oil-fired boiler with a pellet boiler,
  • Install solar panels,
  • Insulate the walls with hemp fibre and close with plasterboard,
  • Install a greywater recovery circuit with UV treatment,
  • Convert a bedroom in the attic,
  • And then a small stove in the living room to make it cozy.

In the end, we didn’t change the oil-fired boiler but we only use it one week a year.

We didn’t install solar panels, but we focused on sufficiency.

We didn’t insulate the walls (they’re 60cm thick), but we dress warmly.

We don’t process greywater, but we produce much less.

We don’t have a cozy stove in the living room but we have built a fireplace with which to cook, bake our bread and heat the house. The same energy has several uses.

 

How did we get here?

At the beginning of the project, I read a book by Pierre Lévy entitled “Ecological Renovation”1. I ignored the message in the preamble: “What is really important when considering a renovation? Deciding to install a solar water heater? Building straw walls? Recommend over-insulation, a wood-fired boiler? No, that’s not the most important thing. What matters is the meaning we give to things, to our actions.”

 

In other words, why do we do eco-friendly renovation?

 

When I started researching even before we bought the house, I didn’t understand what the author meant. I skipped the reflection steps to immediately consult the technical pages to find out how thick the insulation should be.

 

In permaculture, you can’t separate the garden, the house and your daily life. It is a whole that must be thought out. We’ll come back to that later.

 

Our thinking has evolved over the course of encounters and opportunities that have arisen.

An architect we met at the Eco Bio fair in Colmar explained the basics of renovating a 200-year-old stone house:

  1. Insulate the attic. It’s like for humans, you must put on a hat,
  2. Apply an 8cm earth layer to the walls,
  3. Cut off the air blows that run through the house from bottom to top between the front door and the attic door (all Alsatian houses are equipped with this air blows).

A craftsman from the valley who specialises in raw earth offered us to install a custom-made masonry stove.

 

At this stage of the project, we were able to glimpse the heritage enhancement of the house, and the restoration of its primary function: a food farm for a family.

 

Daily life at home in history

If we restore the original function of the house, it is interesting to examine how people lived when it was built in 1798.

Resources were limited and houses were not as well insulated, so how did we heat ourselves?

 

The vigil

It’s counterintuitive, but when it was cold, you didn’t stay at home. We’d go out. From November onwards, at nightfall, the inhabitants met in “La Stub” of a house in the neighbourhood. The Stub is what corresponds to the current living room. People gathered around the fire to spin, sing, chat, and drink a glass of schnapps2, 3. Then we’d go back to bed with sometimes the whole family in the same bed. This saved fuel.

 

Activity and pace of life

Sitting all day in front of your computer and going to the gym at the end of the day is a very recent way of life. Being active all day (working in the fields, crafts, etc.) heats up the body and makes you tired enough to go to bed early. In addition, without a television and electric lighting, people are less likely to sit late in their living room. All of this reduces the need for heating.

 

A story told by Kris de Decker, the founder of Low Tech Magazine, particularly struck me. In an interview4 he quoted a Norwegian who explained to him, about the first insulation programs for wooden houses, that you don’t need to insulate the building, you let the wind blow through it and you go outside to chop wood. And when you come back, just coming back from outside where it’s cold, is enough to feel comfortable, and you go to bed. According to him, the reason why we need heating so much nowadays is that we are significantly less active than our predecessors.

Heat people, not spaces

In the twentieth century, with the abundance of energy and the explosion of passive lifestyles, we have evolved from a logic where we heat people to a logic where we heat the air volumes of buildings. Before the advent of central heating, radiative heating systems such as masonry stoves were used5.

Die Bauern und die Zeitung, une peinture d’Albert Anker, 1867
People gather around a masonry stove. Die Bauern und die Zeitung, a painting by Albert Anker, 1867
Sufficiency

In 1909, when electricity arrived in Maisonsgoutte, filament bulbs gradually replaced candles and kerosene lamps. However, the number of light bulbs per household is limited to 3, and power outlets are prohibited6.

 

One element that is largely underestimated: adaptation to climate change

Climate change is strong and rapid. The warm period is getting longer and more intense. Heat waves are becoming more frequent, and the outlook is for changes to accelerate.

 

Traditional stone houses with small windows are quite well suited. The thick walls provide significant inertia (the temperature inside the building is stable despite the variations outside). They also diffuse their freshness slowly over the course of the summer. In winter, they store some of the heat from the stove and diffuse it throughout the night.

 

This only works if you don’t cut off their mass by insulation… I’m not saying that we shouldn’t isolate but rather consider the options:

  • Insulate from the inside (improves winter comfort, reduces summer comfort)
  • Insulate from the outside (improves winter and summer comfort but hides the architectural features of buildings)
  • Do not insulate. (To avoid over-consuming energy, you must accept less comfort in winter and turn to sober practices and an active lifestyle. The advantage is that it saves the manufacturing, transport, and entry of new materials into the house).

You need to be aware that you can always protect yourself from the cold by adding clothes or a blanket. It’s not possible to protect yourself from the heat effectively (except air conditioning, but that’s ecological nonsense).

 

This is where the global reflection on our lifestyle and the reason why we are renovating comes in, as we saw at the beginning of the article.

  • We chose to cultivate a permaculture garden of almost 1ha because we like to live outside. By being active in this way, we need to heat the house less.
  • As in the evenings of yesteryear, after dark we stay grouped around the stove and accept that the other rooms of the house remain cold.
  • We do not hesitate to turn on the central heating if the temperatures get too low or the comfort of our guests requires it. It was only necessary for one week last winter.
  • We dress warmly (tights, undershirts, …)

Incentives to follow the "standard" route

To think and design your project in this way, you have to resist injunctions from the outside.

 

  • You are often advised not to use insulation from the outside on older houses, and therefore insulate from the inside to allow the “walls to breathe” and avoid the accumulation of moisture and the problems that go with it. However, the opposite is true. To treat the humidity of the walls in a sustainable way, it is necessary to insulate them from the outside (so they are protected) and either leave them visible on the inside or plaster them with earth or lime. They will help regulate the humidity inside the house. By installing a radiant heater, such as a stove, you will ensure that they are nice and dry in the winter and not too dry in the summer. See the article on Pathologies related to humdity in ancient walls – Eco-renovating in the Northern Vosges (parc-vosges-nord.fr) and this excellent video by l’Archipelle on La Maison Résiliente 
  • Above all, the subsidy system promotes energy renovation that is designed and favourable to industry. For example, the fact that we carry out part of the thermal renovation ourselves disqualifies us from the subsidies allocated to global renovations. However, we have designed our project in a much more comprehensive and potentially more sober way than what is provided for in the regulations. In addition, we have acquired countless new skills. The subsidy system is more a system of financing the construction sector (craftsmen, suppliers of materials) than really of assistance to the individual. With labour shortages and unreasonable deadlines for carrying out work, wouldn’t it be in our interest to encourage the training of citizens and for them to have their work checked by a professional? This is already possible for electrical renovations.

The result

In any case, I was proud that a consulting architect from the CAUE (Architecture Council, Environmental Council | CAUE Alsace (caue-alsace.com)) describes the project as exemplary. I’ll give you the details right away:

 

  • The central element of the house: the masonry stove. You can find the details in the article dedicated to it. The wood consumption is 2 times less than for an equivalent house in the village (and half the year we don’t use any other energy for cooking!)
Poêle de masse dans le salon
  • Finishes in earth and lime. We made the plaster mixtures ourselves from locally produced earth and lime. The cost of finishing is lower than the use of ready-to-use paints, wallpapers or earth-lime plasters. Of course, you get a lot of satisfaction, skills and above all a warm and healthy house, well regulated from a hydrological perspective.
  • Dry toilets in the house. Instead of recycling water, we avoid using it. We had a 24-hour water cut last year. With our 1000L (not drinkable) rainwater reserves in the cellar and the dry toilet, we were probably living in the most comfortable house that day. The savings in installation and use are substantial.
  • Thermal curtains to cut air blows from the front door to the attic.
  • A neat insulation of 24cm of wood wool in the attic.
  • Instead of installing solar panels on our house, we join a collective model of electricity production: Meisensolar. The project is to install solar panels on the huge roof of the church in Maisonsgoutte.

Is there anything I would do differently today?

 

Well, yes. Attic insulation. We have opted for a bio-based material that insulates from both cold and heat: wood wool. It comes from sawdust from sawmills in the Black Forest, which is relatively local. That’s not bad, right? But it takes a lot of energy to assemble it into panels, and the industry depends on industrial forest harvesting, which is more like spruce monocultures. The impact is only slightly better than a synthetic material. To install it, we first tore out the plank and took out the mixture of straw and slag (which generated non-recyclable waste). It’s a long and difficult job that gets done in the dust. Another option would have been to install polystyrene panels (partially recycled) directly on the floor. This would have reinforced the existing insulation at a lower cost and with much less effort. This remains to be verified, but it seems that the ecological impact would not have been worse, even if the polystyrene comes from the oil industry (no waste and no energy-intensive wood wool to manufacture).

 

Conclusion

Renovation is a powerful adventure. It takes 2x longer than expected but you discover a lot of things, you learn, and you acquire a ton of skills. Before I started, I barely knew how to hold a hammer and now there’s nothing that feels out of reach.

 

It’s an adventure that makes us think about technique, the meaning we give to things, the history of places and how we see the future.

Sources:

1 Pierre Lévy, La Rénovation Ecologique, Terre Vivante, 2010

2 Radio France: Les veillées d’autrefois 

3 Société d’Histoire du Val de Villé, Annuaire 2023

Kris De Decker: “Low Tech: What, Why and How”| The Great Simplification

5  Low Tech Magazine, Heating people not spaces 

6 Société d’Histoire du Val de Villé, Annuaire 2023

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