Wood from sustainable forests is one of or the best construction materials in terms of sustainability. Trees are turning CO2 from the air into wood and oxygen. So wood is basically CO2 that has been filtered out of the atmosphere. When we are building with wood, we are keeping the harmful CO2 out of the atmosphere.
Depending on where we live our houses are a main cause of CO2 emissions. Depending on where we live because it makes a huge difference whether we live in some place where it's around 20 degrees Celsius all year round or in a place with hard and long winters. Because heating a house needs a lot of energy. Switzerland is a place where it is rather cold during winter so if we find a way to build a house with 0 emissions in Switzerland it should be possible in most if not all other parts of the world too.
In the image here you see the world's first apartment building (with 9 family apartments) that is producing all the energy its residents need. So no connection to any energy grid is needed. No oil has to be delivered. No gas. No connection to the electrical grid. Cooking or heating in winter, hot shower. All the energy comes from the house itself.
The facade and the roof is completely covered in solar pannels. And during the summer when the sun is shining the most, the excess electricity will be used to produce hydrogen and fill up tanks in the basement that will heat the building in winter. In fact, this concept worked so well that the house is producing more energy than it needs which is why in 2019 they decided to actually do connect it to the grid. Not to receive electricity. But to give. Immagine if all houses were built like this. This was a project of the Umwelt Arena Switzerland. More houses like this were built or are currently in construction because it was a full success.
To achieve the goal of a 0 emission house like in the post above or to at least dramatically lower its carbon emissions (in a place with cold winters) there are different technologies available. The most common one are solar pannels. You can also add smaller sized windwheels that don't stick out too much so they won't disturb your neighbours. But because heating in cold winters is extremely energy-intensive additional technologies are required. Heating with wood can be a CO2-neutral technology as well. By wood I mean either burning wood at a fireplace or masonry heater (there are fireplaces that are specifically meant for heating with a glass door to avoid smoke in your rooms). Or pellets, which is a modern way of heating with wood. But heating with wood is only environmentally friendly as long the wood that is being burned comes from sustainable forests which means each cut tree will be replaced by a new one. If everybody that is currently heating with oil or gaz would switch to wood we wouldn't have enough sustainable forests in the world to cover the demand so wood can not be the only solution. That's why other new technologies are indispensable.
Heat Pumps are one of those new technologies.
Producing concrete affords a lot of energy and therefore is responsible for 8% of the worlds total CO2 emissions. In Switzerland the rubble of demolished concrete constructions are being recycled. 50% of it is being used for new buildings and the rest for roadmaking. The Swiss company Neustark now has invented a procedure to reduce concretes CO2 footprint by catching the emitted CO2 from biogas plants and enrich the concrete rubble with it. In a chemical reaction the CO2 will become part of the newly mixed concrete. Tests have shown that concrete enriched with CO2 is even more robust than ordinary concrete. Allowing to reduce the CO2 footprint of buildings made of concrete even more. As less material is needed for the same amount of stability.