On June 1, 2017, the >> German Institute for Building Technology (DIBt) published the draft version of the updated >> Model Administrative Regulation for Technical Building Regulations (MVV TB). The MVV TB serves as an administrative regulation within the meaning of the Model Building Code (MBO) to specify the general requirements for structural systems, construction products and other systems and equipment by means of technical building regulations. It is expected to be published at the end of July 2017.
The draft has led to uncertainty in the domestic ventilation sector as to whether domestic ventilation units with an air flow rate of no more than 1,000 m³/h are still subject to general building authority approval. This open letter, which has been prepared to the best of the TZWL’s knowledge and only reflects the TZWL’s interpretation, explains why the TZWL considers the testing of domestic ventilation units in accordance with DIBt test standards and the approval of these units based on these standards to still be mandatory, based on the building regulations list as the status quo, the Construction Products Regulation (>> Regulation (EU) No. 305/2011), the draft of the MVV TB and the MBO. This interpretation does not imply any legal obligation; for further information on understanding the MVV TB, TZWL refers to the DIBt as publisher.
The Building Regulations List 2015/2 B Part 2 deals with ventilation units in Chapter 1, Technical Building Services, in Section 1.2.4. List B Part 2 is defined as follows in the preliminary remarks to the Construction Products Lists: “Construction products are included in Building Rules List B Part 2 which are placed on the market and traded on the basis of the provisions implementing directives of the European Communities if the directives do not take into account basic requirements in accordance with Article 3 (1) of the Construction Products Regulation and if additional verifications of usability or verifications of conformity in accordance with the building regulations are required to fulfill these requirements; these construction products also require the mark of conformity (Ü mark) in accordance with the building regulations of the federal states in addition to the CE marking.”
The quoted Article 3 para. 1 of the Construction Products Regulation reads as follows: “The basic requirements for construction works set out in Annex 1 shall form the basis for the development of standardization mandates and harmonized technical specifications.” Annex 1 defines the following basic requirements for construction works and thus for the construction products and technical building equipment installed in construction works: 1. mechanical strength and stability, 2. fire protection, 3. hygiene, health and environmental protection, 4. safety and accessibility during use, 5. sound insulation, 6. energy saving and thermal insulation and 7. sustainable use of natural resources.
The classification of ventilation units in Building Regulations List B Part 2 implies by implication that some of the above-mentioned basic requirements for ventilation systems in buildings are not fully covered by the CE mark and that a national mark of conformity is required in addition to the CE mark. This understanding is supported by the registration of ventilation units (1.2.4, p. 177), in which a general building authority approval (Z) is specified as proof of usability in the column “Proof of usability and conformity required in addition to CE marking […]”.
Chapter B of the draft MVV TB deals with domestic ventilation units. Chapter B contains technical building regulations “which must be observed when constructing certain special structures and components.” (MVV TB, B 1) In subchapter B 3, “Technical building equipment and parts of systems for filling and handling substances hazardous to water that do not bear the CE marking in accordance with the Construction Products Regulation”, domestic ventilation units are defined as technical building equipment.
For the construction products dealt with in subchapter B 3, “proof of usability is required to demonstrate the missing essential characteristics under the conditions of Section 17 (1) MBO.” (MVV TB, B 3.1) Missing characteristics are properties of the construction product/technical building equipment that are not yet subject to a harmonized technical specification and are therefore not yet covered by the CE mark within the meaning of the EU Construction Products Regulation (Regulation (EU) No. 305/2011).
The missing essential characteristics that are not covered by the CE mark are therefore: c.1) fire behavior; c.2) characteristic curve, minimum volume flow, tightness, air quality (filter), safety devices; c.3) energy characteristics. In accordance with MVV TB, these characteristics must be verified by a certificate of usability under the conditions of § 17 Para. 1 MBO must be verified.
In § 17 para. 1 MBO states that “a proof of usability (Sections 18 to 20) […] is required for a construction product [ist] if 1. there is no technical building regulation and no generally recognized rule of technology, 2. the construction product deviates significantly from a technical building regulation (Section 85a (2) No. 3) or 3. a regulation pursuant to Section 85 (4a) provides for it.” This paragraph therefore corresponds to the above definition of the construction products/technical equipment dealt with in subchapter B 3, MVV TB.
Sections 18 to 20 of the MBO specify the following as proofs of usability:
- § 18 General building inspectorate approvals
- § 19 General building inspectorate test certificate
- § 20 Verification of the usability of construction products in individual cases
General building authority approvals for construction products are issued in accordance with § 18 Para. 1 by the DIBt “under the conditions of § 17 para. 1 […] if their usability within the meaning of § 16b para. 1 is proven.” According to § 16b, General requirements for the usability of construction products, para. 1 stipulates: “Construction products may only be used if, when used and properly maintained, the construction works meet the requirements of this Act or on the basis of this Act for a reasonable period of time appropriate to their purpose and are fit for use.”
In the understanding of the TZWL, the draft of the MVV TB currently published for comments in conjunction with the MBO therefore in no way eliminates the need for general building authority approval for domestic ventilation units with a maximum air flow rate of 1,000 m³/h. On the contrary, the draft even explicitly points out that a general building authority approval is mandatory in order to prove the essential characteristics of domestic ventilation units that are not covered by the CE mark according to the harmonized EU Construction Products Regulation (Regulation (EU) No. 305/2011) in accordance with the MBO by means of such a proof of usability.