Building Regulations for Removing Internal Walls

The most important first step is establishing whether the wall is load-bearing. A load-bearing wall carries structural loads from the floors, roof, or other walls above it and transfers them down to the foundations. Removing one without adequate replacement support can cause serious structural failure.

Indicators that a wall is likely load-bearing include:

• It runs perpendicular to the floor joists above: Look in the loft or lift a floorboard in the room above. If the joists run parallel to the wall, the wall is less likely to be load-bearing; if they run into the wall (perpendicular), the wall is likely carrying the joist ends.
• It sits directly above a beam or wall on the floor below: Walls are often stacked - a wall on the ground floor may carry a wall above it, which in turn carries the roof. Look at the arrangement of walls on other floors.
• It is located centrally in the house: Central spine walls are often the primary structural wall in a traditional Victorian or Edwardian terrace.
• It has a chimney breast on it: Chimney breasts and stacks add considerable load - the wall they sit on is almost certainly load-bearing.

Always get a structural engineer to confirm. Online guidance and rules of thumb are a starting point only. A structural engineer will carry out a proper assessment and provide the calculations your building control officer requires. Their fee for a straightforward internal wall removal is typically £300-£600 and is money well spent.

The position on building regulations for internal wall removal is as follows:

• Load-bearing wall: Building regulations always apply. You must apply for building regulations approval (Full Plans or Building Notice) and the structural work must be carried out in accordance with structural engineer calculations. A building control officer will inspect the work.
• Non-load-bearing wall: The physical act of removing a non-load-bearing partition wall does not strictly require building regulations notification. However, if the work involves electrical rewiring (which is likely if there are sockets or lights on the wall), that work does require Part P compliance. If it affects drainage (unlikely for an internal wall), Part H applies.

Even where building regulations do not strictly apply, it is worth considering whether to notify building control voluntarily. When you come to sell the property, buyers solicitors may ask about internal alterations. A building control completion certificate provides evidence that the work was done properly.

Approved Document A (Structure) does not set out prescriptive details for every situation - instead it requires that structures are designed to carry the loads placed on them with adequate safety margins. For a load-bearing wall removal, compliance with Part A typically means:

• Structural engineer calculations: The engineer calculates the loads that the wall was carrying and specifies the size and specification of the beam required to replace it. This is site-specific - there is no standard RSJ size for a given span.
• Beam specification: Typically a steel beam (RSJ or universal beam) for spans over about 2 metres, or a concrete lintel for shorter spans. The engineer specifies the beam section (e.g. 178 x 102 x 19 UB), the length, and the required bearing at each end.
• Minimum bearing: The beam must have adequate bearing at each end - typically a minimum of 150mm onto the supporting structure (masonry wall or column).
• Padstones: Where the beam bears onto masonry, engineering bricks or concrete padstones distribute the concentrated load from the beam end into the wall below to prevent the masonry crushing under the point load.
• Temporary propping: While the old wall is being removed, the structure above must be temporarily propped to prevent settlement or collapse. Proprietary Acrow props are typically used, set on spreader boards on the floor above and below.

Installing a steel RSJ in a domestic property requires careful planning. The key practical considerations are:

• Access: Steel beams are heavy. A 4-metre universal beam might weigh 80-100kg. Getting it into position in an occupied house requires dismantling door frames, removing sections of ceiling, and sometimes working through windows.
• Propping sequence: Props must be in place before any load-bearing masonry is removed. Your structural engineer should specify the propping arrangement. Props should bear on solid floor (not on suspended timber floor without spreader boards) and should be plumbed vertically.
• Fire protection: In most domestic situations, steel beams within a floor or ceiling construction need to be encased in plasterboard (or intumescent paint) to achieve the required fire resistance period. Your building control officer will advise on the specific requirement.
• Deflection: All beams deflect slightly under load. Your structural engineer will specify a maximum permissible deflection. Excessive deflection causes cracking in ceilings and walls. If cracks appear after a beam installation, get the engineer back to investigate.

Most internal wall removals in standard two-storey houses do not raise significant Part B concerns. However, there are situations where fire separation requirements are relevant:

• Three or more storey houses: In a house of three or more storeys, the Building Regulations require greater fire separation between floors. An internal wall forming part of the fire-protected escape route (typically the hallway and staircase enclosure) must not be removed or compromised without replacement fire protection.
• Conversion to open-plan where the staircase is involved: If you are removing a wall that currently separates the living area from the hallway and stairs, and the stairs serve bedrooms above, your building control officer may require a self-closing fire door between the new open-plan area and the hallway, or a fire alarm system, to maintain adequate means of escape.
• Purpose-built flats: In flats, walls between properties are often fire-rated compartment walls. These must not be altered. This guide covers houses only.

Technically, a Building Notice is a valid route for internal wall removal. In practice, Full Plans is strongly recommended for any structural work.

With Full Plans, the structural engineer calculations and proposed beam specification are reviewed and approved by the building control body before work starts. If there is a problem with the design, it is identified and corrected before any demolition takes place. This protects you and your builder.

With a Building Notice, work can start without plan approval. If the building control officer visits during construction and finds the beam is undersized or the propping is inadequate, work may need to stop until the issue is resolved. In the worst case, completed work may need to be undone.

The additional cost of preparing Full Plans drawings for a simple wall removal is small - often £200-£400 from an architectural technician. It is worth it for the certainty it provides.

If the wall you are removing adjoins a neighbour (i.e. it is a party wall - a wall on the boundary between two properties, or a wall that separates two semi-detached or terraced houses), the Party Wall etc. Act 1996 applies.

Under the Act, you must serve a party wall notice on your neighbour at least two months before starting work if you intend to:

• Cut into a party wall (for example, to insert a beam)
• Make good or repair a party wall
• Demolish or rebuild a party wall

Removing an internal wall that is entirely within your own property (not shared with a neighbour) does not trigger the Party Wall Act. But if any part of the works involves cutting into or bearing onto a party wall - for example, where a steel beam will bear onto masonry that is a shared wall - the Act applies and notices must be served.

If your neighbour does not consent, a party wall surveyor must be appointed to draw up a party wall award. This sets out how the work will be carried out and protects both parties.

Once the work is complete and your building control officer is satisfied, they issue a completion certificate. For structural work like a wall removal, this certificate is particularly important.

When you sell your property, your solicitor will be asked to provide evidence of building regulations compliance for any structural alterations. Without a completion certificate, buyers solicitors will raise a requisition. Your options at that point are:

• Arrange a retrospective inspection (the officer may ask for finishes to be opened up to expose the beam ends, padstones, and propping arrangement)
• Take out a building regulations indemnity insurance policy

Indemnity insurance is available and relatively cheap (typically £100-£300 for a one-off premium), but sophisticated buyers and their surveyors know it does not confirm the work was done correctly - only that enforcement action is unlikely. A genuine completion certificate is always preferable.

If you are buying a property with a knocked-through ground floor and no completion certificate, instruct your surveyor to inspect the beam installation carefully. Undersized beams are a surprisingly common defect in older open-plan conversions.