Where One Building Ends and Another Begins: Asbestos Duties Across Shared UK Structures
Asbestos management is usually described in terms of a single building and a single dutyholder. In practice, many UK commercial properties do not sit neatly within those lines. Terraces, converted warehouses, mixed-use blocks, retail parades and estate-owned industrial units frequently share structural elements with neighbouring occupiers. A wall may be party to two titles. A floor slab may carry services for several units. A roof void may run continuously above separate demises. When asbestos work is planned in one area, the compliance question is not only whether that work is controlled. It is also whether the adjacent premises remain protected, informed and properly evidenced.
The boundary problem
The difficulty begins with definitions. A lease plan may show a red line at the centre of a party wall, but asbestos-containing materials do not respect title boundaries. Sprayed coatings, insulation, cement panels, gaskets and firebreaks can extend through shared voids or sit within structures that serve more than one occupier. A refurbishment survey commissioned for one unit may therefore stop at a demarcation line that has little practical meaning for dust, access or structural disturbance.
That mismatch creates two risks. The first is an information gap: the dutyholder for the neighbouring premises may not know that intrusive work is planned close to a shared element. The second is an evidence gap: once the work is complete, there may be no clear record that adjacent areas were considered, protected or checked. Both weaknesses can become significant if a later incident, complaint or property transaction requires the asbestos file to be explained.
Mapping shared assets before work starts
Before scoping asbestos work in a multi-occupier building, the project team should identify which elements are genuinely shared. This is not simply a plan-reading exercise. It requires input from the asbestos register, lease documentation, service drawings, fire strategy information and, where possible, a physical inspection of risers, roof spaces and penetrations.
Key shared assets commonly include party walls and their associated cavities, floor slabs and ceiling voids, service risers and ducts, roof structures and waterproofing, plant rooms, and fire compartmentation. Each should be assessed for its relationship to the proposed works. The purpose is not to expand the project unnecessarily, but to establish where disturbance, access or enclosure could have consequences beyond the unit in question.
Where records are incomplete, the assumption should be cautious. A neighbour’s register may be out of date, or may describe only those areas under their direct control. The project team should record what is known, what is presumed and what remains unverified. That record becomes the basis for agreeing the scope with the neighbouring dutyholder and for deciding whether further survey work is needed.
Allocating responsibility without ambiguity
In shared structures, responsibility can be layered. The landlord may hold a duty to manage common parts. Individual tenants may be dutyholders for their demised areas. A managing agent may coordinate works under a service agreement. A contractor may control the physical activity on site. None of these roles automatically absorbs the others.
A written protocol is therefore preferable to relying on informal understanding. It should identify who is commissioning the work, who is responsible for the shared element, who will receive notifications, who can authorise access and who will hold the completed records. Where the work affects a neighbouring occupier, the protocol should also confirm how that occupier will be consulted and what information they will receive.
This need not be a complex legal document. A clear project-specific agreement, appended to the asbestos management plan and referenced in the contractor’s scope, can be sufficient. The important point is that responsibilities are visible before work begins rather than reconstructed afterwards.
Access and notification in practice
Notification is often treated as a courtesy. In shared buildings it is a control measure. Neighbours need enough notice to consider their own operations, occupants and asbestos arrangements. They may need to move stock, restrict access to a shared corridor or arrange temporary services. They may also need to check whether their own asbestos register identifies materials close to the work area.
A practical notification should include the nature and location of the work, the dates and hours of activity, the expected access arrangements, any enclosure or negative pressure equipment affecting shared spaces, and a named contact for questions. It should also explain how emergency situations will be handled. If the work involves a licensed contractor, the notification should confirm that the licence and plan of work have been checked by the commissioning party.
Access agreements should be equally specific. A right to enter a neighbouring unit to erect protection, inspect a shared riser or complete a reassurance check should be recorded in advance, with any conditions attached. Verbal permissions are difficult to defend if a later dispute arises.
Protecting adjacent premises during removal or enclosure
Physical protection should reflect the relationship between the work area and the neighbouring premises. Shared ventilation, unsealed penetrations, damaged fire stops and continuous roof voids can all provide unintended pathways. The contractor’s plan of work should show how these interfaces will be controlled, not merely how the primary enclosure will be constructed.
Where enclosure is used, the boundary conditions deserve particular attention. Negative pressure units should be positioned so that they do not draw air from an adjacent occupied space unless that is a deliberate and assessed part of the design. Seals around services entering the enclosure should be checked before work starts. Where removal takes place close to a party wall, the method should avoid unnecessary disturbance to the shared structure.
Adjacent occupiers should also know what to do if they notice dust, unusual odours or damage. A simple contact route and a commitment to investigate promptly are part of good neighbourly management, but they are also part of risk control.
Evidence for both sides of the wall
The final file should demonstrate that the shared dimension was managed, not merely that the primary unit was cleared. Useful records include the pre-work condition of adjacent areas, the notification issued, access permissions, photographs of protection at shared interfaces, clearance certificates for the work area, and post-work checks of neighbouring spaces where access was available.
Where a neighbouring dutyholder has relied on the project team’s assurances, they should receive a concise completion record. This need not disclose commercial details, but it should confirm the scope of work, the dates, the clearance position and any residual asbestos materials in shared elements. That record supports their own management arrangements and reduces the risk of inconsistent information emerging later.
A practical discipline
Shared structures require dutyholders to think beyond their own red lines. The starting point is a clear map of shared assets, followed by an agreed allocation of responsibility, documented notification and access, physical protection at interfaces, and evidence that adjacent premises were considered before, during and after the work. None of these steps is unusual in isolation. Together they turn a potential blind spot into a defensible part of the asbestos file.
