The future has come, faster than imagined!
On April 20, the Department of Housing and Urban-Rural Development of Jiangsu Province issued an important document-"Guiding Opinions of the Provincial Department of Housing and Urban-Rural Development on Promoting Green Urban-Rural Construction under the Goal of Carbon Peak." The full text is full of more than 7000 words, but the key few words make people have to sigh.
Which sentence does the author have to make this sigh? Let's take a look at it together:
"By 2025, new buildings will be fully designed and constructed according to ultra-low energy consumption standards."

Jiangsu's Ambition
This means that five years later, new buildings in Jiangsu Province will fully implement the new building energy efficiency standards, and the energy saving rate will reach about 82.5 percent. You know, the current energy-saving design standard for residential buildings in Jiangsu Province, "Design Standard for Thermal Environment of Residential Buildings in Jiangsu Province," is still the 2014 edition (DGJ32/J 71-2014), with an energy-saving rate of 65%. However, the new version of the energy-saving rate of 75% of the residential building energy-saving standard is still in the stage of soliciting opinions and has not yet been fully implemented.
Before that, if you ask a practitioner in the building energy efficiency industry-how long do you think it will take, we can fully achieve the goal of ultra-low energy buildings?
Either answer may be pessimistic-originally we thought this was a long way off.
Now, Jiangsu Province gives us a clear answer -2025. In the "Guiding Opinions", Jiangsu Province more clearly stated that its overall goals are:
"By 2025, the total scale of green buildings in the province will remain the largest in the country, and the intensity of building carbon emissions will strive to be the lowest in the country."
The ambition of Jiangsu Province has set an important example for the development of building energy conservation in China. Prior to this, China's building energy conservation, in various provinces and cities to promote, such as the sea waves, layer by layer. Now it is finally Jiangsu Province's turn to carry the banner of comprehensive promotion of ultra-low energy consumption buildings.

The Tide of Building Energy Saving in China

Friends who are concerned about building energy efficiency know that the most important direction of building energy efficiency in the world is energy-saving buildings such as passive houses, passive buildings, ultra-low energy buildings, and near-zero energy buildings. More than ten years ago, these building energy efficiency concepts began to enter China, and gradually began to appear in the country individual pilot.
In 2015, Hebei Province issued the passive building standard "Hebei Province Passive Low Energy Residential Building Energy Efficiency Design Standard" (DB 13J/T 177-2015). This is the first provincial building standard (recommended standard) to promote the concept of passive building design. Hebei Province has thus provoked the banner of building energy efficiency. Passive architecture has been vigorously promoted in Hebei Province. It is believed that this work has made an indelible contribution to the improvement of the atmospheric environment in the Beijing-Tianjin-Hebei region in recent years.
In 2020, Beijing officially issued a new residential building energy-saving design standard "Beijing Residential Building Energy-saving Design Standard" (DB11/891-2020), which further increased the local building energy-saving rate from 75% to 80%. This energy-saving level is a step away from the 82.5 percent energy-saving rate of ultra-low-energy buildings. Beijing took the lead in raising the energy-saving design standards of residential buildings in various provinces and cities across the country to the level of "five-step energy-saving", far ahead of other provinces and cities.
Now, Jiangsu Province has further rushed to the front of building energy efficiency, positioning the building energy efficiency target of Jiangsu Province as an ultra-low energy consumption building with an energy saving rate of 82.5-in 2025.
Passive houses, passive buildings, ultra-low energy consumption buildings, near-zero energy consumption buildings... These energy-saving buildings are the mainstream trend of global building energy efficiency. This time, in this global wave in the field of building energy efficiency, China is also trying to follow up, not left behind.

Industry impact

At present, the norms, standards and relevant government documents on building energy conservation are all benchmarking the higher requirements of building energy conservation. Especially after General Secretary Xi put forward the goals of "carbon peak", "carbon neutrality" and "30-60", these tasks have become more clear. After all, in order to achieve China's strategic goal of "carbon peak" in 2030 and "carbon neutrality" in 2060, building energy conservation is inevitable.
These goals are the development direction of the construction industry, the development opportunity of the building energy-saving industry, and the important development opportunity of the insulation engineering industry. These goals, put forward higher requirements for the construction industry--
For example, for our domestic developers, the core business used to be financing to buy land, and then bidding, construction, and sale. Now that new standards have emerged, the operation mode of real estate will also need to be transformed and more technological content will need to be added. Not just building houses, but building quality houses.
For example, our design unit previously needed to set local standards for architectural design. Now, the new standard requires a new design concept, requires the design unit must be on the local climate environment, the surrounding environment analysis, the need for building energy consumption simulation calculation, iterative design, optimize the selection of exterior windows, insulation materials, HVAC equipment, so as to improve the indoor comfort, more conducive to the health of the residents.
For example, our construction unit, the previous extensive construction practices, will have to be adjusted to more knowledge application and technical content of fine construction. The construction process requires not only strict project management, but also the service of energy-saving calculation, the fine treatment of thermal bridge, and the good cooperation of various specialties. Only in this way can we obtain more owners' recognition and industry recognition in future energy-saving projects such as heat preservation. I believe that in a few years, we will be able to see that the construction industry will no longer be the image of sloppy migrant workers under the extensive and messy scene, but will be transformed into the image of engineers with more engineering technology applications.

Popular science: what is the "building energy saving rate"

In fact, the term "building energy efficiency" is a very young concept. Before the oil crisis in the 1970 s, building energy efficiency was an insignificant concept. After the oil crisis, Europe and the United States, especially the energy shortage of European countries put forward clear requirements for energy conservation and environmental protection. Building energy efficiency is an important part of energy-saving work, and it has also begun to become a field of in-depth research by construction industry experts.
Building energy efficiency in our country started from the late 1970 s. In the 1980 s, China formally defined the "step-by-step" development strategy of building energy conservation, and implemented it in the form of standards and norms to gradually reduce building energy consumption and improve the level of building energy conservation.
The "first step" of building energy efficiency is that in the late 1980 s, Beijing and other regions issued building energy efficiency standards, taking the building energy consumption in the early 1980 s as a benchmark to improve the building energy efficiency requirements and reduce building energy consumption by 30%. This is the origin of the "30% energy saving rate.
By the late 1990 s, the design standards for building energy efficiency in various places were gradually updated, forming the "second step" of building energy efficiency in my country. On the basis of the "first step" of building energy efficiency, energy consumption was reduced by about 30%. The energy consumption of buildings under the new code is equivalent to 50% of that in the early 1980 s, which is the "50% energy saving rate".
In the first decade of the 21st century, the design standards of building energy efficiency in various provinces and cities have been further improved. On the basis of the "second step" of building energy conservation, that is, the "50% energy saving rate", the energy consumption will be reduced by about 30%. This is the "third step" of building energy conservation in China, and the building energy conservation in China has reached the level of "65% energy saving rate. Building energy savings are about 65% higher than in the early 1980 s, and energy consumption is roughly equivalent to 35% of the early 1980 s.
Up to now, there are still a large proportion of provinces and cities in the country that are implementing the building energy efficiency standard of "65% energy saving rate.
But at the same time, in the 2010 s, there are many provinces and cities such as Beijing, Tianjin, Hebei, Shandong, Jilin, etc., began to further improve the building energy efficiency standards. On the basis of the original "65% energy saving rate", the energy consumption is further reduced by about 30%, thus achieving the "fourth step" of building energy saving, that is, the goal of "75% energy saving rate.

Popular Science: What is the next step in the "four-step energy saving?

After realizing the four-step energy saving, what is the next goal of building energy saving in China?
This was once a question asked and explored within the industry.
In 2019, the recommended national standard "Technical Standard for Near Zero Energy Buildings" (GB/T 51350-2019) was released, which answered this question to some extent.
The "near zero energy consumption building technical standards" will be the goal of building energy efficiency in the future to further refine, subdivided into three categories:
The first category, on the basis of "75% energy saving rate", will further increase the building energy saving rate to 82.5. Buildings that achieve this goal can be called "ultra-low energy buildings". The building energy consumption of such buildings is equivalent to 17.5 percent of the building energy consumption in the early 1980 s. This is an already quite high level of energy saving. Some domestic construction experts believe that this kind of "ultra-low energy consumption building" has reached the category of "passive house" in Germany and other European countries.
The second category is to further improve the building configuration and increase the building energy saving rate to 86%, which means that the energy consumption level is equivalent to 14% in the early 1980 s. Buildings that achieve this goal can be called "near-zero energy buildings".
The third category is to improve the utilization rate of low-carbon renewable energy such as solar energy and wind energy on the basis of the configuration of "near-zero energy consumption buildings", so as to achieve a certain degree of energy self-sufficiency, that is to say, to achieve the balance between building energy consumption and its own production capacity. Then, the building energy saving rate is equivalent to increasing from 86% to 100, that is to say, the energy consumption level is further reduced from 14% of the building energy consumption in the early 1980 s to "zero energy consumption" (here I can't help but want to ask proudly, incredible). This kind of building we can call "zero energy building".
 
In fact, there is another type of building that goes further than "zero energy buildings. That is the "capacity building" mentioned in the "near zero energy consumption building evaluation standard" (T/CABEE 003-2019), which is edited by China Building Energy Efficiency Association and specifically evaluates the "near zero energy consumption building technical standard". This requires an increase in the building's capacity equipment-the building's own capacity can not only cover its own energy needs, but also export energy. At that stage, the concept of architecture will once again be redefined by us: architecture is not only the space we live in and use, but also the provider of energy.
 
What is the higher standard of building energy efficiency development path? It can be said that the "near zero energy consumption building technical standards" for us to draw a clear and detailed development path map.
After the energy-saving rate of buildings in various provinces and cities reaches 75%, what is the next step for building energy conservation?
There are voices in the industry that the energy saving rate should be further increased to 80% on the basis of the existing 75% energy saving rate. At present, the "Beijing Residential Building Energy-saving Design Standard" (DB11/891-2020), which was launched by Beijing last year and officially implemented on January 1 this year, embodies this idea.
However, there is also a voice that, on the basis of the existing energy saving rate of 75%, it will be further improved to the level of energy saving rate of 82.5, and the technical standard for buildings with near zero energy consumption (GB/T 51350-2019) will be fully connected. It can be said that the "Guiding Opinions" issued by Jiangsu Province this time reflect this kind of thinking. On the basis of the 75% energy-saving standard to be implemented in Jiangsu Province, the goal of ultra-low energy consumption buildings will be fully implemented in five years, and the energy-saving rate will be increased to 82.5. Jiangsu Province will provide a special building energy efficiency development ideas and reference path for other provinces and cities in the country.
Here, we have to see that no matter what kind of sound, the level of building energy efficiency will continue to improve. Beijing's 80% energy saving rate will not be the end of its building energy efficiency. Jiangsu province to achieve full coverage of ultra-low energy buildings will be how to go. These are all directions that we need to continue to observe and explore.

Improve energy saving, but also to enhance indoor comfort

Some readers may be confused: What does building energy efficiency have to do with me? Can the electricity savings from the increased energy efficiency of my house really cover my house price or construction cost?
It is more difficult to answer this question because houses have different types of use, different body types, and different window-to-wall ratios. To build ultra-low energy buildings, different regions, different building climate environment, different construction standards, will have a huge impact on the building.
However, from the user's point of view, ultra-low energy consumption building charm.
 
First of all, ultra-low energy buildings greatly improve the indoor comfort of the building. In the "near zero energy building technical standards", the indoor temperature environment value is set:
Not lower than 20 ℃ in winter and not higher than 26 ℃ in summer.
All energy consumption calculations are based on this comfortable prerequisite. In other words, while maintaining the same indoor comfort, ultra-low energy buildings will greatly reduce building energy consumption. In other words, under the same energy consumption level, your living environment thermal comfort will be greatly improved.

Second, the indoor air quality such as PM2.5 and CO2 is included in the standard requirements of ultra-low energy consumption buildings. In this way, the residents not only have a house to live so simple, but also the indoor air environment can be greatly improved, no haze pollution, there is no high concentration of CO2 infringement.
 
Third, ultra-low-energy buildings have introduced fresh air systems to improve the problem of poor indoor air in households. This kind of fresh air system is not a common indoor air purifier with internal circulation and filtering function, but introduces outdoor fresh air, and provides clean fresh air for indoor residents through dust filtration, sterilization and other links. This can lead to a healthier experience for indoor occupants.
Fourth, ultra-low energy buildings have strengthened the control of building thermal bridges. This is particularly important for residents of certain areas. We often see moldy walls in some houses. This moldy fungus and its scattered spores will have a negative impact on the indoor air environment, leading to the emergence of allergic symptoms in some households. There are many people who think that the moldy wall is caused by indoor humidity.
However, in fact, the thermal bridge is also an important cause of wall mold. Ultra-low-energy buildings incorporate thermal bridge control into construction standards, which can reduce the possibility of indoor mold, thereby reducing the dispersion of indoor fungi and other pollutants and improving our healthy lives.