Renovating an occupied building can create safety risks that are easily overlooked when construction work is divided between individual contractors. A new access control system may affect the operation of a fire door, a relocated partition can change the coverage of fire detectors, and modifications to building automation may interfere with established emergency procedures. German safety consultancy UDS Beratung GmbH has highlighted the importance of assessing these connections before refurbishment work is commissioned. The issue extends well beyond Germany: across Europe and international markets, building owners, security integrators and contractors face the challenge of modernising facilities while preserving the performance of existing fire protection and life safety systems. Understanding how fire doors are tested, how their approved configurations are defined and how different safety systems interact is central to managing that challenge.
Refurbishment projects are increasingly undertaken in offices, industrial facilities, hospitals and other buildings that remain operational throughout construction. Although the physical changes may appear limited, their consequences can extend across several interconnected systems. Fire detection, access control, emergency lighting, smoke management and automatic door operation may all depend on the original building layout and its established fire safety strategy. In a technical advisory published on 30 October 2026, Germany-based UDS Beratung recommended that project teams assess affected safety functions before issuing individual installation orders. The company advocates a coordinated change specification that identifies technical interfaces, assigns responsibilities and includes the testing and documentation required before the modified building returns to normal operation. While this is a project management approach rather than a new legal requirement, it addresses an important weakness in refurbishment planning: a building can contain individually functioning safety devices without those devices necessarily responding correctly as an integrated system.
Fire doors are tested assemblies, not ordinary doors with fire-resistant materials
One of the most important considerations in refurbishment projects concerns fire doors. Their purpose is to help prevent fire and, where specified, smoke from spreading between designated areas of a building. In practical terms, a fire door forms part of the building’s compartmentation strategy, which divides the structure into areas intended to limit the spread of a fire and protect escape routes. Unlike an ordinary door, a fire-resisting doorset is assessed for defined performance characteristics. These may depend on the combined behaviour of the door leaf, frame, hinges, glazing, seals, locking components and closing mechanism. The assembly must maintain its intended protective function under the conditions for which it has been tested or otherwise assessed. This means that fire resistance is not simply a property of the door material but of a complete construction whose components must function together.
European standards provide a common technical language for describing this performance. EN 1634-1 specifies a method for testing the fire resistance of doors and shutter assemblies, while EN 13501-2 provides the corresponding classification system. An important distinction is made between integrity, represented by the letter E, and thermal insulation, represented by I. Integrity concerns the ability to prevent flames and hot gases from passing through the construction, while insulation concerns the limitation of heat transfer to the unexposed side. For example, a doorset classified as EI₂ 30 has demonstrated specified integrity and insulation performance for 30 minutes under the relevant test and classification conditions. The number is not a guarantee that the door will contain every real fire for precisely that duration; it describes a standardised performance classification that enables designers and regulators to compare products against the requirements of a particular building. Smoke control is assessed separately, with classifications such as Sₐ and S₂₀₀ identifying performance under specified test conditions. A door’s fire resistance classification should therefore not automatically be interpreted as proof that it also meets every smoke control requirement. These distinctions matter because a fire door is not simply a collection of individually fire-rated parts. Its performance depends on the configuration in which the complete assembly has been tested, classified or otherwise accepted.
Why certification does not permit unrestricted modifications
A common problem arises when an existing fire door is modified to accommodate new building functions. Consider an office refurbishment in which a mechanical door is to receive electronic access control. The proposed work may involve an electric locking component, a reader, additional wiring or modifications to the door frame. From an access control perspective, the task may appear relatively straightforward. From a fire protection perspective, however, it raises a different question: does the modified assembly remain within the scope of the evidence supporting its original fire resistance and smoke control performance? A certificate, classification report or other product approval does not necessarily authorise every subsequent modification. Additional holes, replacement hardware, altered glazing or changes to closing mechanisms may affect the tested configuration. Whether a particular modification is acceptable depends on the applicable product documentation, the scope of permitted variations and the relevant national requirements.
For international readers, it is important to distinguish between European product rules and national building regulations. The European Construction Products Regulation provides a framework for assessing and declaring the performance of construction products placed on the European market. However, European legislation does not establish a single uniform set of rules governing the installation and use of every construction product in buildings. These decisions remain subject to national regulatory requirements. For certain categories, including external pedestrian doorsets and industrial doors with fire-resisting or smoke control characteristics, EN 16034 operates together with the applicable harmonised product standard. In these cases, the relevant European framework provides for a declaration of performance and CE marking. Not every type of fire door follows precisely the same route, and CE marking should not be confused with unrestricted permission to install a product in any building or alter it without further assessment.
Germany provides a useful illustration of this distinction. The German Institute for Construction Technology, known as the Deutsches Institut für Bautechnik (DIBt), is a national authority responsible for technical approvals and related building regulatory functions. For internal fire-resisting and smoke control pedestrian doorsets that are not covered by the relevant harmonised product standard, the German system requires specific national evidence of suitability. This may take the form of an allgemeine bauaufsichtliche Zulassung (abZ), a national technical approval addressing the suitability of the product, or a project-related approval issued by the competent authority. The construction method itself may require an allgemeine Bauartgenehmigung (aBG), commonly translated as a general construction technique permit. This concerns how the relevant construction system is designed and executed. In simpler terms, evidence that a product can achieve a specified fire performance is not always the same as permission to install or alter that product in any chosen configuration. A component may be suitable in principle but inappropriate for a particular existing doorset. Although the terminology and approval procedures differ between countries, the underlying engineering requirement is widely relevant: before modifying a fire-resisting assembly, project teams must establish that the proposed configuration remains adequately supported by the applicable technical evidence and local regulations.
Access control and emergency escape must be designed together
The relationship between access control and fire safety becomes particularly important when a protected door also forms part of an escape route. Electronic security systems are commonly designed to prevent unauthorised entry, while emergency evacuation requirements may require occupants to open the same door quickly and without special knowledge or equipment. Both functions must be considered when selecting locks, controllers and emergency release mechanisms. In Germany, the Workplace Ordinance and the associated technical rule ASR A2.3 establish requirements for escape routes in workplaces. Within their applicable scope, escape route doors must be readily openable from the inside without special aids when people need to use them. ASR A2.3 also specifies requirements for electrically locked escape route doors, including emergency release arrangements and behaviour in the event of power failure. These are German workplace requirements, not universally applicable rules for all EMEA countries. Elsewhere, the relevant provisions may be found in national building codes, fire safety legislation or occupational safety requirements. Nevertheless, the technical problem is comparable: access control must not create an unacceptable barrier to escape.
A refurbishment specification should therefore describe the intended behaviour of the complete door system rather than merely listing the components to be installed. This includes how the door operates during normal use, which conditions trigger release or closure, how emergency operation is achieved and how the correct function will be tested. Where the door also forms part of the building’s fire compartmentation strategy, the required fire resistance and smoke control functions must remain compatible with the access control arrangement. A successfully installed electronic lock does not, by itself, demonstrate that the door remains safe as both an access-controlled entrance and part of an emergency escape strategy. The relevant functions must be evaluated together against the building’s intended use and applicable national requirements.
Hold-open systems require compatible components and defined approvals
Another frequent refurbishment requirement concerns doors that are intended to remain open during normal building operations. Fire doors are often required to close automatically to maintain compartmentation, but permanently closed doors can create operational difficulties in busy corridors, healthcare facilities and commercial premises. An electrically controlled hold-open system can provide a solution. It allows a suitable door to remain open under normal conditions while releasing it to close when a relevant fire or smoke condition is detected. Such a system typically includes a detector, a triggering mechanism, the hold-open device, a power supply and a manual release arrangement. In Germany, DIBt identifies hold-open systems as combinations of interacting components and issues general construction technique permits establishing, among other matters, the compatibility of devices and permitted combinations.
This regulatory terminology deserves explanation because a German general construction technique permit is not simply a certificate confirming that one component has passed a laboratory test. It provides a defined basis for the design and execution of a particular construction system, including requirements relevant to the way its components operate together. Consequently, the addition of a hold-open magnet cannot be treated as an isolated electrical installation. The existing door must be suitable for the intended arrangement, the required components must be compatible, and the system must be installed in accordance with the relevant technical documentation and applicable national rules. Commissioning and subsequent maintenance must also be planned. In Germany, the applicable construction technique permit and related requirements govern the necessary acceptance procedures, while the DIN 14677 series addresses maintenance of electrically controlled hold-open systems. These are distinct responsibilities and should not be treated as interchangeable. Other countries may apply different approval, inspection and maintenance frameworks, but the essential safety principle remains that the complete hold-open arrangement must reliably allow the fire or smoke protection function to operate when required.
A cause-and-effect matrix makes system interactions visible
Fire safety becomes even more complex when multiple building systems are connected. A signal from a fire detection system may need to release hold-open devices, activate smoke extraction equipment, change the operation of ventilation systems or initiate a defined response from lifts. These actions are not necessarily identical throughout a building, and their required sequence depends on the fire safety design and the protected areas involved. One method of coordinating these functions is a fire alarm cause-and-effect matrix, also described in some projects as a fire scenario matrix. The document identifies the initiating events and the corresponding responses required from each connected system. For example, a detector activation in one area may require selected fire doors to close while particular smoke management functions are activated. The matrix can also specify expected feedback, fault indications, timing conditions and procedures for restoring systems to their normal operating state.
The benefit is that all contractors work from a common functional description rather than separate assumptions about how their own equipment should behave. A fire alarm contractor may verify that an output signal is transmitted, while a door contractor confirms that an actuator operates, without anyone demonstrating that the complete safety function performs as intended. When a building’s layout or technical installations change, the cause-and-effect documentation should therefore be reviewed to determine whether the original sequences remain appropriate. Modifications to detection zones, door locations or building automation may require corresponding changes to the matrix and the verification procedures. A cause-and-effect matrix is not universally mandated for every small refurbishment. Its necessity and detail depend on the building, applicable requirements and complexity of the interconnected systems. For installations involving several interacting life safety functions, however, it provides a valuable basis for design coordination and integrated testing.
Refurbishment creates risks before the final system is commissioned
A further challenge arises because refurbishment work takes place over time. During construction, parts of the existing safety infrastructure may be temporarily unavailable, even where the finished installation is designed to provide an improved level of protection. Fire detectors may need to be isolated while dusty construction work takes place, access routes may be diverted, doors may be removed temporarily and alterations to the building layout may affect the visibility or coverage of existing detection equipment. These changes can create risks for occupants, contractors and emergency responders, making it necessary to assess the consequences before the affected safety systems are altered or taken out of service. A refurbishment project cannot therefore be evaluated exclusively in terms of the safety performance of its completed installation. The conditions prevailing during each construction phase must also be considered.
Responsibility is shared according to the relevant legal framework and contractual arrangements. Building owners, operators, employers and contractors may each have specific duties, and the precise allocation varies across jurisdictions. The important project management requirement is to establish who is authorised to approve temporary restrictions, who coordinates the necessary safety measures and who confirms that normal protection has been restored. Depending on the circumstances, temporary arrangements may include changes to occupancy, additional supervision, revised emergency procedures or other compensating measures approved through the appropriate process. Such measures cannot be selected generically; they must reflect the actual risk and the requirements applicable to the building. The temporary operating condition therefore deserves as much attention as the final design, since even a technically successful refurbishment cannot compensate for unmanaged risks to occupants during the construction period.
Commissioning must verify the complete safety function
Once construction work is complete, individual equipment tests are necessary but may not be sufficient to demonstrate that the building’s safety functions operate correctly. A fire detection system may successfully identify an alarm condition, and an electrically operated door may respond correctly during its own functional test. What still needs to be established is whether the intended action occurs when those systems are connected and operated under the relevant emergency scenarios. Integrated commissioning addresses this gap by examining the functional relationships between the modified systems. Depending on the building and its requirements, testing may cover alarm initiation, door release, closure, system feedback, fault handling and the restoration of normal operation. The commissioning programme should be defined before work begins, identifying which functions require testing, who is responsible for each procedure and what evidence is needed before the modified areas can return to unrestricted use. Any statutory inspections, approval-related acceptance procedures or independent verification requirements must also be incorporated.
Documentation is equally important because a system that functions correctly at handover must remain understandable and maintainable throughout its subsequent service life. Updated plans, equipment records, cause-and-effect matrices, certificates and maintenance instructions should reflect the actual installation. Where operating procedures have changed, the relevant building personnel must be informed and trained. This documentation also supports future refurbishment, particularly in buildings that undergo repeated alterations over many years. Without reliable records, it can become increasingly difficult to determine whether existing equipment still corresponds to its original design, tested configuration and approved installation conditions. A complete handover therefore serves not only the immediate commissioning process but also the longer-term safety management of the property.
The financial case for coordinated planning
The safety argument for integrated refurbishment planning is accompanied by an economic one. When contractors are appointed separately without an agreed description of the complete safety function, technical conflicts may emerge only after equipment has been ordered or installed. This can create additional design work, replacement of incompatible components, delays in commissioning and unexpected costs. Such difficulties can be particularly disruptive in occupied buildings, where restricted access or extended construction periods may affect business operations. A coordinated change specification can reduce uncertainty by identifying technical dependencies and required verification activities before contracts are awarded. It can also improve clarity regarding responsibility for documentation, acceptance testing and ongoing maintenance.
This does not mean that integrated planning necessarily reduces costs in every project. Additional engineering and coordination work may increase expenditure during the design phase, but its value lies in improving the quality of the project scope and reducing the risk of avoidable disputes or late-stage modifications. For owners managing building portfolios across several countries, there is an additional consideration: a standardised internal change-management process may be useful, but local legal and technical requirements still need to be assessed for each site. European product standards can help establish a common technical language without replacing national rules on installation, operation and fire safety. The most effective procurement strategy is therefore one that combines a consistent method of project coordination with appropriate attention to the regulatory and technical conditions of each building.
Outlook: Building safety depends on the performance of the complete system
The concerns raised by UDS Beratung extend beyond the refurbishment of individual doors or alarm installations. They illustrate a broader challenge in modern buildings, where fire protection, physical security and automation increasingly operate as interconnected systems. For international building owners and security integrators, the distinction between product performance evidence, national approval procedures and system-level commissioning is especially important. A fire door may have a documented resistance classification, but that classification does not automatically validate every subsequent modification. A hold-open device may perform correctly as an individual component, but its suitability depends on the complete arrangement. Similarly, an alarm output may operate as specified without proving that the intended emergency sequence has been achieved.
These distinctions become particularly critical when buildings are altered while occupied. Every modification should be assessed against the existing fire safety strategy, the applicable regulatory framework and the interaction between affected systems. The process begins with a reliable understanding of the existing installation and continues through coordinated design, procurement, installation, testing and documentation. The central lesson is that building safety cannot be secured through individually approved products alone. It depends on how those products are selected, installed, connected, tested and maintained as part of a functioning building. For refurbishment projects across EMEA, the most effective starting point is therefore a coordinated assessment of safety functions before the first installation contract is awarded.
Editorial sources
- UDS Beratung GmbH – Refurbishment during ongoing operations: Clarifying safety functions before commissioning work, original German technical advisory, 30 October 2026.
- European Commission – Construction Products Regulation, European framework for construction product performance and market access.
- DIBt – Fire-resisting and smoke control external doorsets, European harmonised standards and CE marking.
- DIBt – Internal fire-resisting and smoke control doorsets, German national approval requirements.
- DIBt – Hold-open devices, system compatibility and general construction technique permits.
- European Union – Fire resistance classification of doors and shutters, classification principles under EN 13501-2 and EN 1634-1.
- BAuA – ASR A2.3, Escape Routes and Emergency Exits, German workplace requirements.
- UK Government – Fire Safety (England) Regulations 2022: Fire door guidance, illustrating the distinction between existing-door assessments and current product requirements.
