Rettelsesblad til Bygningsreglementets vejledning om konstruktioner (kapitel 15) – Load-bearing Capacity Assessment
This amendment sheet (Rettelsesblad), issued on 23 January 2024 by the Danish Social- og Boligstyrelsen (Social and Housing Authority), introduces a new section to the guidance for Chapter 15 of the Danish Building Regulations (Bygningsreglementet). The document specifically inserts Section 2.4, which establishes the regulatory framework for Bæreevnevurdering af eksisterende konstruktioner (load-bearing capacity assessment of existing structures). It functions as a legal clarification for property owners, structural engineers, and municipal authorities regarding the assessment of buildings that have already been granted an occupancy permit (ibrugtagningstilladelse).
The scope of this regulation covers the criteria under which an existing structure's load-bearing capacity is considered legal and the specific conditions that necessitate a new technical assessment. It defines structural elements as existing once a permit for use has been issued. The document outlines the relationship between current maintenance requirements under § 357 and historical compliance with the building codes and standards in effect at the time of the original building permit application. It explicitly addresses remodeling (ombygning) and changes (forandring) that affect the static function of existing components.
Professional practitioners are directed to specific technical standards for performing these assessments. The guidance clarifies the application of DS 11990 (Bæreevnevurdering af eksisterende konstruktioner) and sets strict prerequisites for using specialized annexes within that standard for higher construction classes. The document ensures that structural safety evaluations for existing building stock follow a standardized methodology aligned with national engineering practices.
Legality of Existing Load-bearing Structures
A structure's load-bearing capacity is regarded as legal if it met the building regulations and technical standards applicable at the time of the original building permit application. This legality is maintained through ongoing compliance and maintenance as defined in the following criteria:
- Original compliance: The construction adheres to the building regulations and standards valid when the building permit was requested.
- Subsequent works: Any later modifications that altered the structural function must comply with the regulations and standards active at the time of those specific works.
- Maintenance (§ 357): Operation, control, and maintenance must ensure the structure remains free of defects or damage affecting load-bearing capacity.
Triggers for Load-bearing Capacity Assessment
A technical assessment of load-bearing capacity becomes necessary when changes or remodeling affect the static performance of existing building parts. Triggers for such assessments include:
- Changes in static function or structural behavior.
- Alterations in usage or load conditions (lastforhold).
- Modifications to the construction, specific building components, or the immediate surroundings.
- Identification of significant damage, errors, or defects.
While the assessment applies to existing parts, the construction of entirely new building components is not covered by these specific assessment rules for existing structures.
Technical Standards and Construction Classes
Assessments of existing structures, sections, or components must follow the principles described in DS 11990. Specific limitations apply to the use of advanced assessment methods based on the project's classification:
- DS 11990 Annex F: This annex may only be utilized for structures in Construction Classes 2-4 (konstruktionsklasse 2-4).
- Static Investigation Report: Use of Annex F requires a completed static investigation report in accordance with DS 11990, Chapter 2.
Frequently Asked Questions
When is a building construction officially considered 'existing'?
A construction is considered existing once a formal occupancy permit (tilladelse til ibrugtagning) has been issued for the building.
What standards must an existing structure meet to be considered legal?
It must comply with the building regulations and standards that were in effect at the time the building permit was applied for, provided it has been properly maintained.
Does remodeling always require a load-bearing assessment?
An assessment is required if the remodeling or change affects the static behavior, usage, load conditions, or if damage and defects are present.
Which Danish standard governs the assessment of existing structures?
Assessments should be carried out according to the principles in DS 11990, titled Bæreevnevurdering af eksisterende konstruktioner.
Can DS 11990 Annex F be used for all buildings?
No, Annex F can only be used for buildings categorized in Construction Classes 2-4 and requires a static investigation report per Chapter 2 of the standard.
Who issued this amendment to the building regulations guidance?
The amendment was issued by the Danish Social- og Boligstyrelsen on 23 January 2024.
