2018/0395/B
EC/EFTA
BE Belgique
  • B10 - Construction materials
2018-11-05
2018-08-13

The European Energy Performance of Buildings Directive (EPBD 2010/31/EU) requires all new buildings to be nearly zero-energy (NZE) by 2021. This goal was set out in the Energy Decree in 2014. In 2015, the Flemish Energy Agency (Vlaams Energieagentschap; the ‘VEA’) launched the process to prepare the fourth EPB review. The fourth review of the energy performance regulations naturally examines the experiences over the nearly ten years of EPB requirements since 2006, but it primarily focuses on the objective of making all new buildings nearly zero-energy (NZE) by 2021. In the 2015 EPB evaluation, the VEA examined whether the various aspects of energy performance regulations (requirements, methodology, procedures) were ready for NZE buildings. This was based on findings from several policy preparation studies and on consultation with the sector.

Gradually ramping up EPB requirements will ensure that new buildings become increasingly energy efficient. The process will use increasingly innovative technology and materials. Because requirements are being strengthened, the sector will devote more attention to calculating energy performance figures for buildings. A refined calculation method is required for adequate and detailed energy performance calculations for NZE buildings.

The 2019 method amendments are now being implemented. This draft amending decree also contains a number of technical adjustments to the EPB calculation methods. The main adjustments are for the changes to the EPW and EPN calculation methods (see below).

- Draft Decree of the Flemish Government amending the Energy Decree of 19 November 2010, concerning various provisions on energy;

- Annex 1 (replacing Annex V – EPW calculation method);

- Annex 2 (replacing Annex VI – EPN method).

Article 52 (on the replacement of Annex V)

The requirements that new buildings must meet in the area of energy performance are becoming increasingly stringent. More and more innovative technologies and materials are being used to meet these increasingly stringent requirements. As a result, the calculation method must also be refined for proper and accurate incorporation of these new materials and technologies.

Adjustments to the calculation method are developed within the EPB platform. This is a consultation platform between the three regions, which has been supported by a consortium of scientific partners since 2014. Based on several studies completed by the EPB consortium in 2016, amendments are being applied to the calculation method set out in Annex V (EPW method). The summary below explains the main amendments:

- Section 7.6 refines and expands the calculation method for the effective thermal capacity of an energy sector. A study by the EPB consortium has shown that for heavy buildings, the existing EPW method results in a significant overestimation of thermal capacity, compared to detailed calculation as per NBN EN ISO 13786. The use of scale factors as proposed in NBN EN ISO 13790 may reduce discrepancies and achieve more uniform values for effective thermal capacity. The values in Table 2 have been adjusted for this. In addition, the option to calculate the thermal capacity in detail has also been added.

- In Section 10.2.3, several amendments have been made to enable detailed incorporation of decentralised generating systems into the calculation. In previous years, this has already been applied for sanitary hot water and central heating. The current amendment also enables the individual efficiency values for local generators to be added. The method shall be based on Ecodesign wherever possible.

- In 10.2.3, the option is also added to factor in an air-to-air heat pump with a capacity of over 12 kW based on the Ecodesign information.

- In Section 11.2.2.1, the default values are amended for electrical auxiliary energy consumption. The existing default values have proved too favourable, often producing lower E-levels than the detailed method. As this runs counter to the basic EPB principles, the EPB consortium aimed to determine better default values.

- In Section 15.3, several terms associated with hot tap water are added to the formula for the percentage of renewables from heat pumps, so a heat pump boiler can also be factored into the minimum renewable energy percentage.

- In Section C.3, an error is corrected in the sun exposure calculation.

Article 53 (on the replacement of Annex VI)

Based on several studies completed by the EPB consortium in 2016, amendments are applied to the calculation method from Annex VI (EPN method). The summary below explains the main amendment:

- For generation efficiency from decentralised heat generators, reference is made to Annex V to the Energy Decree. This means Ecodesign data are also entered for non-residential units where possible.

- In Section 7.5.1, the method for VRF systems is refined (multi-split systems that can heat and cool at the same time). This amendment allows greater accuracy when factoring in heat recovery.

- In Section 11.3, several terms associated with hot tap water are added to the formula for the percentage of renewables from heat pumps, so a heat pump boiler can also be factored into the minimum renewable energy percentage.

Article 54 (on amendments to Annex VII)

Following the simplification of the nature of the works starting in 2014, updates were made to the definitions of the nature of the works and the corresponding articles setting out requirements in the Energy Decree of 19 November 2010. This reduced the number of types of works from 11 to 3, consolidating 7 types of work activity under the category ‘new construction (or equivalent).’ When imposing the requirements for 2014, this text clarified the parts of the requirements applicable to each work activity. For instance, for the various types of ‘partial reconstruction’, requirements were only imposed on new components, not on the existing structural components. The reclassification, starting in 2014, imposed the requirements on all structural components. In the specific case of works that may retain existing components but are still classified as new constructions, this resulted in the imposition of requirements on undisturbed structural components as well. In practice, however, this has proved difficult to achieve in many cases, such as with unmodified basement walls or structural components in contact with the ground.

For the above reasons, it has been proposed that Annex VII to the Energy Decree of 19 November 2010 also stipulate that the requirements for structural components shall only apply to new, renovated or newly insulated structural components, not to existing structural components that are not being renovated. Given that all other requirements shall remain in full force, including the E-level, stimulation is still adequate for the optimal performance of existing components, without them having to meet the individual requirement.

Article 55 (on amendments to Annex IX)

Annex IX to the Energy Decree of 19 November 2010 sets out ventilation requirements for residential buildings. In principle, this largely follows standard NBN D50-001. In addition, some provisions from the standard were changed from ‘requirements’ to ‘recommendations’. Moreover, the annex itself also sets out several additional requirements which do not appear in the standard. Thus, for instance, point 2 imposed additional requirements on adjustable intake openings with regard to insect-proofing, rain-proofing and placement height. Although these three aspects were given the status of requirements, the Energy Decree of 8 May 2009 does not set out any specific penalty for failing to meet them. Solely for the purposes of adjustability, the annex to the Energy Decree of 8 May 2009 explicitly states that the flow rate of the adjustable intake opening (RTO) must be deemed equal to zero if the relevant requirement is not met. Thus, a penalty may be imposed for failure to meet the ventilation requirements. Given that the three aspects under point 2 are not concretely enforceable and are actually analogous to the properties designated as requirements in the standard but as recommendations in point 1.c of the Annex (e.g. air-tightness, acoustics, thermal performance, intensive ventilation, comfort, etc.), it has been proposed to give these additional requirements the status of additional recommendations, and to stop classifying them as ‘requirements’.

Article 56 (on amendments to Annex X)

For non-residential spaces, buildings are sometimes erected without prior knowledge of their ultimate function. These shell buildings may be used for various functions in the future. If the EPB declaration must be submitted owing to the submission deadline and the ultimate function is still unknown, then it is difficult to determine the ventilation requirements for such spaces at that time. After all, this requires a notional estimate of the future layout and function.

Therefore, a separate function was specially devised within the EPN method: the ‘unknown’ function. This uses average values for function-specific parameters (e.g. indoor temperatures, usage times, etc.) that can be applied to the different functions. This provides values for the calculation that are neither too flexible nor too rigid. A similar approach has been proposed for the ventilation requirement here. The proposal is to add a new type of space to Table 1 of Annex X to the Energy Decree of 19 November 2010 that can be used for shell spaces and whose corresponding floor area per person is an average value from the rest of the table.

Moreover, the floor area requirements for sports clubs (aerobics spaces, fitness spaces, bowling alleys) in Annex X are tightened with regard to ventilation requirements (3.5 instead of 10 m²/person). The lower the floor area requirement, the more ventilation must be provided.

Article 57 (on amendments to Annex XII)

Annex XII to the Energy Decree of 19 November 2010 sets a requirement on the output capacity of direct electrical heating. However, the description in Chapter 6 contains a mixture of the terms electrical capacity and output capacity. Yet because these are two completely different terms, this wording may cause confusion. It has therefore been proposed to adjust this wording and remove the reference to ‘electrical capacity’.

Article 58 (transitional provision)

Annexes V, VI, VII, IX, X and XII to the Energy Decree of 19 November 2010, as replaced or amended under this Decree, shall apply, for the first time, to files whose notification or environmental permit application for urban development activities is submitted on or after 1 January 2019.