The Energy Saving Ordinance, or EnEV for short, sets binding standards for the energy efficiency of construction projects. For the building owner, this results in regulations ranging from the maintenance of an energy certificate to insulation and the use of renewable energies in the electricity mix. All building applications submitted after 01.01.2016 must comply with the requirements of EnEV 2014.
the essentials in brief
- Alongside the Renewable Energies Act (EEG), the Energy Saving Ordinance (EnEV) is an instrument used by the German government to implement internationally agreed climate protection targets.
- The EnEV 2014 imposes a number of obligations on building owners from 2016: Installation of efficient technical systems, maintenance of an energy certificate, use of renewable energies, insulation values to be complied with, level of primary energy requirement.
- In addition to the actual final energy demand of a building, the primary energy demand also includes the energy required for the generation, storage and transport of energy sources. Multiplying the final energy demand by the primary energy factor gives the complete energy balance. For fossil fuels, the primary energy factor is comparatively high; for renewables, it is 0.
What is the Energy Saving Ordinance – EnEV 2014 about?
The goal defined by the legislator is a climate-neutral building stock in Germany by 2050. Climate neutrality means that either no more CO2 is released at all or the amount released is compensated. Alternative energy sources and consistent building renovations are thus increasingly coming into focus. The EnEV (along with the Renewable Energies Act – EEG) is an instrument used by the German government to implement the obligations it has entered into with regard to climate protection – building owners are also increasingly being held accountable for this by having to comply with rising minimum standards.
The EnEV has been tightened step by step in the past. For example, the EnEV 2009 stipulated that attics must be insulated. The EnEV 2014 also set a fine of 50000 EUR for violations. In addition, the EnEV 2014, which will apply from 2016, tightens the energy standards for new buildings in particular. Further steps can be expected in the future.
What do female builders need to consider?
1. energy certificate
An energy certificate resulting from the planning phase must already be submitted for the building permit. In addition, it is obligatory to keep an energy certificate for the finished house, which provides information about the energy values. During the construction phase, the values may change, so that, if necessary. an adjustment of the energy certificate is necessary. In any case, the values should be re-evaluated by an authorized building inspector after the house is completed. It is the responsibility of the builder to ensure that a valid Energy Performance Certificate is on file with the completed home. Here you can find more information about the building permit.
2. heating, hot water, ventilation, cooling
All newly built houses must comply with the EnEV 2014 guidelines in terms of energy consumption for heating, water heating, ventilation (ventilation systems) and cooling. Of course, the guidelines only refer to the energy efficiency of the technical systems to be installed, not to the lifestyle of the occupants. Here you will find detailed information on heating technology and ventilation systems.
3. primary energy
The EnEV 2014 also sets new requirements with regard to primary energy demand (see below). All new buildings may now consume 25% less primary energy than was permitted under the 2015 minimum values.
The annual primary energy demand (Qp) for new buildings permitted from 2016 is calculated by multiplying the annual primary energy demand of the reference building by a factor of 0.75. This means that the specifications of the reference building must even be undercut.
Possible structural measures for compliance: strong insulation, ventilation systems with heat recovery, solar support for heating technology, solar domestic water heating, solar systems, solar thermal (also in combination with pellet heating), heat pumps, biogas (heat network), natural gas heating (also with solar thermal), oil/gas hybrid heating.
4. share of renewable energies
For new buildings with a usable floor area of more than 50 m², part of the energy demand (heating or cooling energy demand) must be covered by renewable energies (Renewable Energies Heat Act (EEWärmeG).
Renewable energy sources in this context are: solar radiation energy, biomasses, environmental heat, geothermal energy.
However, this obligation may be circumvented if:
➤ The energy efficiency of the building is at least 15% above the EnEV requirements. This can be achieved, for example, through very good insulation measures.
➤ Connection to heating networks that obtain at least 50% of their energy from combined heat and power (CHP) plants.
5. transmission heat loss
The heat loss of the building envelope must not exceed a specified standard. It is necessary to provide a sufficiently strong insulation of the house. The energy quality of the building envelope is calculated as the so-called “specific transmission heat loss” (H’T) related to the heat-transferring enclosure surface. (The amount of the permissible transmission heat loss (H’T) can be seen in a table as an annex to the EnEV and can be found on the Internet).
The requirement for insulation increases by about 20 % with the EnEV 2014. In addition, with the EnEV 2014 ceilings that connect to the unheated attic may not exceed the heat transfer coefficient (U-value) of 0.24 W/(m2K).
Possible constructional measures for compliance: shoring of windows with very good thermal insulation quality, thicker masonry, thermal insulation by specific plastering .
In summary, the EnEV 2014 stipulates the following for new buildings:
Reduction of energy losses of the building envelope by 20%.
Reduction of primary energy demand for heating, cooling and water heating by 25%.
Reduction of the primary energy factor for electricity from 2.4 to 1.8
The reference building
How is it determined in the planning phase how much energy is needed for heating, hot water preparation and the operation of ventilation and cooling systems? The annual primary energy demand (Qp) and the heat loss of the building envelope (transmission heat loss H’T) are particularly important.
With the help of a virtual reference building created with special software, these values can be determined. The reference building has the same geometry, orientation and usable floor space of the planned house, and is also assumed to have a plant technology and exterior components that meet the standards of the EnEV.
Funding by the Kreditanstalt für Wiederaufbau (KfW)
To qualify for funding through one of KfW’s various programs, the general energy efficiency standards of EnEV 2014 must be exceeded. For building owners who have opted for a KfW Efficiency House-40, for example, the following applies: Only 40 % of the annual primary energy requirement of a new building that meets the standards of EnEV 2014 may be consumed. The tightening of the EnEV standards is therefore simultaneously reflected in a tightening of the subsidy standards. Here you can find more information about the Kreditanstalt für Wiederaufbau (KfW).
The primary energy demand
The German Energy Saving Ordinance (EnEV) sets an annual maximum permissible value for total energy consumption for heating, hot water preparation, ventilation and cooling. The annual energy demand of a building is measured as the annual primary energy demand (Qp). It is expressed in kilowatt hours (KWh/m²year). The kilowatt-hour is used to measure the consumption of both electricity and heating.
But what does primary energy demandmean? Why is the final energy demand ofa building not sufficient? The primary energy demand also includes all processes of energy generation and supply upstream of the actual consumption, which also require energy. These include: Extraction, processing, storage, transport and loss. This therefore goes beyond the final energy demand (heating, hot water preparation, ventilation, cooling) of the building. Thus, the primary energy demand is also always higher than the final energy demand.
Primary energy demand can be used to make much more meaningful judgments about CO2 emission savings. This is mainly because the primary energy demand makes statements about the use of different energy sources. This is because it differs with the use of different energy sources. If a heating system is operated with electricity from the power plant, the primary energy demand is higher than if the heating system is operated via solar thermal. In contrast, it makes no difference whether fossil or renewable energies are used as a measure of final energy demand.
The primary energy factor
The so-called primary energy factor determines the ratio of the type of energy carrier used to the final energy. The greater the share of renewable energy in the electricity mix, the lower the primary energy factor and thus the lower the primary energy requirement. For example, the final energy demand must be multiplied by 1.8 when electricity is used as heating energy. When using wood as an energy source, only 0.2. For the use of renewable energies, the factor is 0.
With the EnEV 2014, the primary energy factor for electricity was lowered from 2.4 to 1.8. This is roughly equivalent to the additional 25 % primary energy that every new building will have to save with the EnEV 2014 from 2016. The tightening of the EnEV 2014 is therefore greatly weakened, as the lowered primary energy factor for electricity already brings the required savings in full. Thus, the use of electricity is excluded from the tightening, thus strengthening the role of electricity as an energy carrier on the market. The sense of such a measure is debatable – in any case, the handwriting of the electricity lobby is recognizable here.
Primary energy factors:
Fuel oil – 1.1
Natural gas – 1.1
District heating, from CHP, renewable fuel – 0.0
Electricity before 2016 – 2.4 / Electricity from 2016 – 1.8
Solar heat, environmental heat – 0.0
A uniform energy balance
The EnEV combines the previously separate areas of the Heating Installations Ordinance and the Thermal Insulation Ordinance. This makes it possible to offset factors that lead to higher or lower energy loss in the overall balance of the house. If, for example, a building has a very modern heating system but is poorly insulated, these two factors will offset each other in the overall energy balance.
With the EnEV 2014, the internationally agreed targets with regard to climate protection will also be noticeable for building owners: New buildings must meet certain energy efficiency standards and an energy certificate must be kept. Provisions are also made on the electricity mix to encourage the advance of renewable energy. There is enough modern construction technology to meet the requirement. Ecologically demanding builders can also exceed the standards set by law – energy efficiency is possible at even higher levels and is also subsidized by the state!