Certificate of Occupancy (Building)

Certificate of Approval (Construction) is an official document that certifies the suitability of construction products, construction methods, or technical systems for use in the German construction industry when these are not covered, or not fully covered, by harmonized technical standards. In Germany, it is issued by the German Institute for Building Technology (DIBt) in Berlin and was known as the “general building approval” (abZ) until it was replaced by the European Technical Assessment (ETA). Today, the term is still sometimes used colloquially, but generally refers to the general type approval (aBG) or the ETA.

General Building Approval and Its Successors

Until 2018, the General Building Approval (abZ) was the central instrument for approving non-standardized construction products. It was replaced by two instruments: the general type approval (aBG) for types (systems, structures) and the general type approval upon application for innovative products. In parallel, there is the European Technical Assessment (ETA) for European harmonized construction products, which leads to CE marking. For contractors and designers, this distinction is important because the respective documents have different scopes of application and legal effects.

The aBG not only regulates whether a product may be used, but also how it must be installed: information on installation rules, permissible areas of use, structural requirements, and fire safety requirements are an integral part of the approval. Designing architects and specialist engineers are obligated to include only approved products in their plans-otherwise, they are liable for any resulting damage. Contractors also bear responsibility: anyone who installs a product without valid approval is acting in violation of regulations and jeopardizes their warranty status.

Relevance for Building Owners and Renovators

In renovation and modernization projects, building owners encounter the approval certificate primarily in the following areas: specialized insulation systems (e.g., ETICS with special anchors), non-standardized waterproofing systems, innovative composite anchors, or special structures in timber construction. If an approved product is replaced with an unapproved one, this can jeopardize insurance coverage, prevent approval by the building authority, and lead to warranty issues in the event of damage. Builders should therefore always verify whether the products used have a valid approval.

A particularly relevant area in practice is External Thermal Insulation Composite Systems (ETICS): Anchors, adhesives, reinforcement mesh, and finish coats must be approved as a complete system-it is not sufficient to combine individual components from different manufacturers, even if each is certified on its own. System approvals ensure that all components are compatible with one another and that the system as a whole meets the specified performance requirements. Homeowners who purchase materials on their own and have them installed by contractors should actively address this point and obtain written confirmation of the system approval.

The same applies to timber construction: wood fasteners, metal brackets, and screw systems used in load-bearing structures require approval or a technical assessment-especially if they involve geometries or application scenarios that deviate from the standard. In historic buildings in Nuremberg with half-timbered sections, special fasteners are often used that require such an assessment.

Validity Period and Renewal

Approvals are time-limited: General type approvals are typically granted for five years and can be renewed upon application. European Technical Assessments (ETA) are generally valid indefinitely but must be updated in the event of significant product changes. It is important for building owners and designers to check the validity period at the time of use-an expired approval no longer offers protection. The DIBt database (www.dibt.de) displays currently valid documents with their validity periods in real time.

If it is determined during a construction project that a product’s approval has since expired, the planner must verify whether an extension application has been filed or whether an equivalent successor product can be used. In case of doubt, the building authority should be consulted-especially if the measure requires approval.

Practical Tip for Property Owners in Nuremberg and Franconia

For renovation projects in Nuremberg and the Franconia metropolitan region, we work closely with regional architects and specialist planners who are familiar with the current approval requirements. The use of approved products is mandatory, especially for subsidized renovations (KfW, BAFA)-failure to provide proof may result in the recovery of subsidies. We recommend requesting written confirmation of the valid approvals for all essential building products from the contractor before construction begins.

In practice, we regularly observe in the region that while owners compare prices when soliciting quotes from contractors, they often fail to consider product quality and approval status. Anyone renovating Nuremberg’s existing building stock-whether a Wilhelminian-style villa in Laufamholz, a post-war bungalow in Zabo, or a condominium renovation in Langwasser-should request that the relevant approval numbers be specified in the scope of work. This costs nothing extra and protects against liability risks.

Frequently Asked Questions

Where can I find current approvals for construction products?

The German Institute for Building Technology (DIBt) maintains a publicly accessible database of all valid general type approvals and European Technical Assessments at www.dibt.de. There, you can search by product type, manufacturer, and approval number. The database is continuously updated and also displays expired documents, allowing you to verify whether an older product may still be used under a continuing approval.

What happens if a product used does not have a valid approval?

With non-approved products, there is a risk that the building authority will refuse acceptance, that subsidies will not be paid out or will be reclaimed, and that insurance coverage will lapse in the event of damage. In serious cases, demolition may be ordered. Particularly with the KfW Federal Funding for Efficient Buildings (BEG), the requirements for product quality and proof of approval are clearly regulated-if proof is missing, the grant recipient risks having to repay the entire repayment subsidy.

Are CE marking and a certificate of approval the same thing?

No. CE marking is based on harmonized European standards and certifies compliance with these standards. For products not fully covered by such standards, a European Technical Assessment (ETA) or a national type approval is additionally required. A CE mark alone therefore does not mean that a product may be used for every application in Germany-the proof of suitability must be verified in the specific installation case.

What is the difference between a system approval and a product approval?

A product approval certifies the suitability of a single construction product under defined conditions. A system approval, on the other hand, evaluates the interaction of multiple components as a unit-such as in ETICS systems, waterproofing systems, or fastening systems. In the case of system approval, the individual components may generally only be used in the approved combination. Unauthorized substitution of individual parts invalidates the system approval and jeopardizes the entire structure from a liability perspective.

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