The article is from A&B issue 7-8|23
According to information compiled by Architecture 2030, a nonprofit organization formed in response to climate change, the construction sector is responsible for roughly 40 percent of annual carbon dioxide production. This total is a combination of two figures: 27 percent comes from the operation of buildings, while about 13 is the so-called embedded carbon footprint, which is created by construction itself (the use of building materials and so on). And it stays in the building forever. Unsurprisingly, some have pointed out that we should not be thinking about how to build, but whether to build at all, if only because every building built, while functioning, generates further amounts of carbon dioxide, and thus accelerates climate change.
However, it is hard to imagine at this point that we stop building houses altogether for climate reasons. So, if we were to return to the question: how to build a house, taking into account the issues of climate change, one answer would be: build in such a way as to reduce as much as possible, and preferably completely eliminate the negative impact of the building on the planet. What does this mean in practice? What can be done to meet such requirements? What should investors pay attention to? I will try to answer these questions.
A house built in modular technology from elements of wooden construction, and filled with heavily compressed straw (straw-bale)
Photo: © EcoCocon
climate
According to the report Climate of Poland 2022, published by the Institute of Meteorology and Water Management - National Research Institute, the average area air temperature in Poland was 9.5 degrees Celsius, 0.8 degrees higher than the average calculated over the period 1991-2020. The summer of 2022, the period from June to August, was the second warmest summer since the middle of the 20th century. This is the third annual report on the Polish climate issued by IMGW-PIB. "When the First Report of the Intergovernmental Panel of Experts on Climate Change (FAR IPCC) was released in 1990, the material it contained on the Earth's contemporary climate change and its causes, consequences and the scope of necessary actions to avoid the associated risks was considered in many countries only a scientific vision. One of many. Since then, however, each successive IPCC report has confirmed and made it increasingly clear that the Earth's climate has been changing since the mid-nineteenth century at a rate never seen before, and that ongoing warming poses a threat to the well-being of the planet, its ecosystems and human life." - can be read in the introduction of the aforementioned report written by Professor Miroslaw Miętus, Director of the Center for Research and Development and Deputy Director of IMGW-PIB.
EcoCocon - outer layers
pic: © EcoCocon
The report compares average annual thermal conditions for the years from 1951 to 2022. Until the mid-1980s, they were described as cool, cold or normal. From the mid-1980s to 2005, cool years are interspersed with normal or warm years. In contrast, since 2006, more and more years have been warm or even extremely warm (2019, 2020). The country's average temperature is one of the indicators by which we can talk about climate warming. Others are extreme phenomena, such as large temperature amplitudes in a single month (such was December 2022), as well as droughts (Lodz has published a guidebook "Let's fight drought together!", which informs residents on what actions to take to minimize the risk of water shortages, such as using small-scale retention or not watering gardens with tap water). At the other extreme pole are, for example, heavy rainfall, which can cause urban flooding. There is also an observed rise in the water level of the Baltic Sea, which threatens some areas of Pomerania and Zulawy. This is only a handful of information, but it shows the picture and background in which modern buildings are and will be built.
EcoCocon - layers from the inside
pic:© EcoCocon
impact
Information about climate change is widespread - everyone has more or less knowledge about it. The case is different with more specialized issues of residential architecture. What should a builder and architect consider when knowing the facts about climate change? What construction and architectural issues are affected by a warming climate? The topic is complex, because the construction process consists of many elements, many decisions, in which one can choose better or worse solutions.
EcoCocon panels are characterized by fire resistance REI 120 and REI 120ef - the heat transfer coefficient for a 10 cm panel is 0.119 W/m2*K
Photo: © EcoCocon
Considering ecological issues, it is important to take care of the smallest possible carbon footprint, both for the construction phase (so, for example, choosing the right materials) and rethinking the design, so that the operation of the house in the following years does not generate large amounts of CO2. It is important to conduct the construction process in the most environmentally friendly way possible, i.e. to ensure that there is as little waste as possible, and those that are, to be properly segregated, disposed of. It is worth choosing local materials to reduce their transportation.
Ecologically and economically, the energy balance is important. On the one hand, it is possible to reduce as much as possible the uncontrolled escape of energy through thermal bridges or poorly made thermal insulation, on the other hand, it is important to use renewable energy sources instead of the traditional ones based on fossil fuels. And choosing home appliances with low energy consumption and high efficiency.
EcoCocon panels are characterized by REI 120 and REI 120ef fire resistance - the heat transfer coefficient for a 10 cm panel is 0.119 W/m2*K.
Photo: © EcoCocon
Thermal comfort issues in homes are important not only in winter, when we reheat the interiors. Nowadays it is becoming equally important to cool or prevent the house from heating up in the summer. In addition to the thermal insulation itself, it is worth taking care of the home's passive cooling capabilities; tall deciduous greenery is great for this, shading windows, roofs and walls in the summer, so the house heats up less. On the other hand, in winter, when there are no leaves, the sun can heat the interior of the house through the glass in the windows. A good solution is blinds, awnings, pergolas or other types of movable elements of facades and terraces, which can be controlled depending on the weather and season, letting in the desired amount of solar radiation. In terms of indoor thermal comfort, recuperation, that is, mechanical ventilation with heat recovery, is not without significance.
Transportation and installation of panels on site significantly speeds up the construction process; in addition - straw has a low carbon footprint and naturally sequesters carbon; it is often a waste material from grain production, so its use in construction is an environmentally friendly solution
photo: © Ecomodus
Climate change also affects hydrological issues. Taking into account the torrential rainfall that occurs due to the rising temperature of the planet, when facing the choice of a site for the construction of a house, it is worth checking, for example, where the range of the 100-year water runs, that is, whether the area has been flooded in the last hundred years. It is also worth envisaging a place for a retention tank that collects rainwater from roofs and terraces. Such a solution is useful not only in drought-stricken areas, but wherever this water can be used for watering the garden or as gray water for flushing toilets.
transporting and installing the panels on site significantly speeds up the construction process; in addition, - additionally, straw has a low carbon footprint and naturally sequesters carbon; it is often a waste material from grain production, so its use in construction is an environmentally friendly solution
photo: © Ecomodus
Important decisions can also be made at the stage of design and functional layout. Simple, compact body, uncomplicated roof, minimization of external wall areas make the building easier to heat. Grouping "warm" rooms on the south side, and technical rooms, staircases - on the north side is also a favorable solution. It is also important not to create redundant spaces - instead of inflating rooms into square meters, it is better to design rooms sufficient to provide the planned functions. Minimizing the number of window openings on the north side, and designing them mainly on the south side allows you to take advantage of solar energy. The use of eaves, which provide protection from the sun in summer, and create a buffer warmer space in winter, preventing heat loss. Of course, it is also important to choose the right materials, with good parameters to maintain thermal comfort inside the house.
Transportation and installation of the panels on site significantly speeds up the construction process - in addition, straw has a low carbon footprint and naturally sequesters carbon; it is often a waste material from grain production, so its use in construction is an environmentally friendly solution
Photo: © Ecomodus
carbon footprint
Thebuilding materials responsible for most of the carbon footprint in construction are concrete, steel and aluminum. The Architecture 2030 organization suggests zero-carbon buildings, i.e., switching to the principle of reuse, which applies to both the reuse of buildings and building materials, reduce, i.e., optimizing building materials and selection inaccordance with a low carbon footprint, and sequester, carbon sequestration, i.e. preparing a process that prevents large amounts of CO2 from escaping into the atmosphere, so filtering factory exhaust and capturing CO2, planting forests that can absorb adverse carbon dioxide.
Straw-bale houses are not visually different from buildings built in the traditional way
photo: © Ecomodus
Architecture 2030 has developed a palette of building materials (Carbon Smart Materials Pallete®) with information about their carbon composition and how it can be reduced through changes in the manufacturing process, such as choosing recycled wood or wood from certified plantations. You can also find information on what a specific carbon footprint is, that is, at what point in the production of a given material it is created. The palette includes the most commonly used materials, such as concrete, steel, wood, insulation and drywall. It also includes items referred to as Carbon-Smart - materials that absorb carbon dioxide or have an insignificant carbon footprint. These include bamboo, wood, sheep's wool, hempcrete (lime made from hemp) or straw-bales made from heavily compressed straw or rice stalks. Straw-bale technology is available in Poland, manufacturers of this type of modular building elements include Ecomodus and EcoCocon. Straw-bales are non-combustible, due to the very strong compression of the material, and have excellent thermal insulation parameters. They also allow quick installation on site - the panels are prepared at the factory, and only the assembly of the panels takes place on the plot.
Houses in straw-bale technology do not visually differ from buildings built in the traditional way
Photo: © Ecomodus
