The foundations of the E-number calculation, which regulates the energy efficiency of buildings, are shaking when electricity is turning from bad to good. Also, the benefits received by solid wood construction will become even more inappropriate when environmental aspects will be assessed in the future through low-carbon regulation. At the same time as the reform of the Land Use and Construction Act (MRL), unnecessary penalty and amnesty coefficients must be removed from energy efficiency control.
The current E-number calculation was introduced in July 2012. The E-number was defined at that time as "the building's annual calculated consumption of purchased energy per heated net area, weighted by the coefficients of energy forms". By using coefficients of energy forms, we wanted to emphasize environmental values, i.e. how much emissions were generated from energy production. At the same time, the coefficients were also intended to favor district heating for social and political reasons.
Although at that time it was already possible to estimate the carbon footprint of energy production with sufficient precision, more detailed information about the carbon footprints of different forms of energy was not yet utilized, and for this reason we ended up with coefficients. I myself have always thought that the result of the E-number calculation describes the "environmental efficiency" of the building more than the energy efficiency.
In the MRL reform, a new essential technical requirement, low carbon, is becoming part of the regulation. It is demonstrated by calculating the carbon footprint, where the energy used during the life cycle of the building is also taken into account and weighted with the CO2 emission coefficients of different forms of energy.
Electricity turns green faster than district heating
Published by the Ministry of the Environment in the emissions database it is assumed that CO2 emissions from energy forms will decrease in the future, albeit more moderately than previously announced emission reductions. At the moment, the emissions of electricity and district heating are roughly the same, but electricity will clearly turn green faster than district heating.
The coefficients used in E-number calculation are 0,5 for district heating and 1,2 for electricity. Initially, both coefficients were higher, but the ratio between them has remained the same. From the point of view of E-number calculation, electricity is therefore 2,5 times "worse" form of energy than district heating.
The coefficients contradict the low-carbon requirements of the proposed buildings and the calculation of the carbon footprint, and their justifications are lame to say the least. Now, in connection with the MRL reform, it would also be necessary to change the E-number calculation to really describe the building's energy efficiency. In the simplest terms, either the coefficients of the previously used energy forms are removed or changed to numerical values of one. In this case, only the amount of purchased energy of the building would be measured, which reflects well the energy efficiency itself.
The loophole is still open and is being exploited out of spite
Another challenge of E-number calculation concerns the treatment of different building materials. With the tightening of thermal insulation regulations in 2012, log-built small houses would no longer have met the new requirements. Due to this, relief was given to these buildings in the regulations, citing the building tradition. At the same time, the Ministry of the Environment was also made to understand that in the next revision of the regulations, this relief would be removed and log-built small houses should be made as heat-insulating and energy-efficient as other buildings.
However, this was completely reversed when, in connection with the reform at the beginning of 2018, the reliefs were expanded: these now apply to solid wood construction and all categories of use, not just small houses. The reliefs were especially justified by the "environmentally friendly properties of solid wood construction and the records of the government program". However, no estimates of emission reductions were presented for environmental friendliness.
Relief is given both for the limit value of the E number (10–20 percent depending on the category of use) and for the equalization calculation (0,40 can be used as the U-value of the outer wall, 0,17 for others). Due to these, the most common exterior wall structure of daycare centers is currently 205 mm thick solid wood (CLT or log) without thermal insulation. The U-value of such a wall is 0,53, while the U-values of the most common wall structures are between 0,12 and 0,17. The lower the U-value, the better the thermal insulation.
In 1975, as a result of the energy crisis, a requirement was given for the maximum U-value of external walls: 0,4. A wall structure that wastes as much energy has therefore not been allowed to be built in Finland since then - except again in recent years, as long as it is made of wood.
I pointed out this loophole in my blog post at the end of 2017, and unfortunately it has turned out exactly as I predicted. Lightweight solutions have become more common, especially in public construction projects, where cost savings and wood's low-carbon reputation have guided the choices.
Facilitation should favor better instead of worse
Such a solid wood building consumes more than twice as much energy as other permitted construction types. However, the central goal of the energy efficiency regulations is energy saving. Even if emission-free or low-emission energy is sufficiently available in the future, it will not be free. Energy consumption is always ultimately paid for by the owner or user of the building.
All building materials can be used to make energy-efficient, low-emission and long-lasting buildings. It is difficult to understand why concessions are made to make things worse. If we really want to encourage the desired solutions, shouldn't we get relief to do better?
Based on the "environmentally friendly properties" of solid wood construction, low energy efficiency of buildings should no longer be allowed in the future. In connection with the low-carbon regulation included in the MRL reform, there is a reason to remove the reliefs given to different building materials from the E-number calculation and thus put the different solutions on the same line.
Fair competition will certainly also strengthen the product development of different materials and structural solutions and tighten all actors to promote both energy efficiency and low carbon. The future users and owners of the buildings especially benefit from this.
Jani Kemppainen
agent, construction development and energy efficiency
Confederation of Finnish Construction Industries (CFCI)
The current E-number calculation enables large heat losses in structures by choosing a "suitable" heating method, which is usually based on heat pumps. When the review is based on annual/monthly purchase energy consumption, one misses what this combination (large heat losses + usually undersized heat pump) means for the need for electrical power. That is, when electricity production is most critical, large consumption peaks occur. On the other hand, when the production of solar electricity is being increased, the overproduction of electricity becomes an even bigger challenge during the summer. The new calculation goal must therefore include the electric power inspection and the means of limiting it.
Another strangeness is related to primary energy coefficients and e.g. for CHP processing. At least in Motiva's report, the CHP portion of electricity also included industrial CHP, but only district heating CHP in heat. How have these been treated in the calculation? Similarly, the report had an interesting sentence: "Solar electricity, solar heat and small wind power are not in theory primary energy in themselves, although they are usually interpreted as such in statistics, various standards and the calculation of PEF coefficients; the original unconverted primary energy in these cases is solar radiation or wind." So how is fuel oil a primary energy and even for a factor of 1?
Let's go back to energy form factors. District heating-oriented planners have received an excellent tool from primary energy. When producing energy for use, some is wasted. For example, in a back pressure power plant, a small part of the coal burning is wasted along with the cooling water. In their great wisdom, these fools have stated that two-thirds of the nuclear power plant is "wasted". Dividing results in an energy form factor of 3,0. Since a large part of the electricity is nuclear electricity, the coefficient of electricity is also weak. It was originally supposed to be 2,2 (?), but was toned down to 1,7. It was too blatant. 2018 was reduced to 1,2.
But what's wrong with a nuclear power factor of 3,0. What's wrong with that is that the part of the energy going to the sea in the process has as little importance as the part wasted by the sun or the wind. It is not taken away from anyone or anything. With coal and other fossil fuels, unusable waste means an unnecessary climate burden. The energy form factor of nuclear power should be lower than that of district heating. My educated guess is that the objective factor approximates the solar and wind factor. They have no multiplier. It may be that the actual coefficient of nuclear power is of the order of 0,05...0,1. What should be the coefficient of electricity when the subjective effect of the coefficient of nuclear power is eliminated?
More about the energy form factor of electricity. Part of the coefficient consists of the share of electricity produced in addition to district heating. District heating is considered a by-product and the actual loss is charged to electricity. In this way, the coefficient of district heating could be found to be small even when produced with coal.
Jan Vapaavuori, as Minister of Housing, once promised that Chapter E would affect the real estate tax. I built a passive house. I also pay property tax for walls that are twice as thick.
Isn't that solid wood construction a marginal phenomenon. In wooden apartment buildings, there are no reliefs for the E chapter. The thickness of the wood of the isolated wood element is not sufficient for solid wood in the E-calculation. So there will be no relief.