We will survey all accessible floors in the property and provide plans showing all visible walls, windows, doors, spot height levels, ceiling/roof heights, window sill/head heights.
The short answer
If the wall is load bearing, you need a structural engineer. That is not optional: Building Regulations require structural calculations for removing or altering a load bearing wall, and building control will ask for them.
A measured building survey is not a legal requirement, but it is what makes the engineer’s design reliable. Beam spans, bearing positions, floor levels and ceiling heights all come from it. For anything beyond removing a single small partition, commissioning both is the safest and usually the cheapest route overall.
If the wall is a genuine non load bearing partition, you may need neither, but you still need to prove it is not load bearing before anyone picks up a hammer.
Is the wall load bearing?
A load bearing wall carries weight from above (floors, roof, other walls) down to the foundations. Remove it without support and that load has nowhere to go.
Common signs a wall may be load bearing:
- Floor or ceiling joists run perpendicular to it and rest on top of it.
- There is a wall directly above it on the floor above.
- It is solid masonry rather than a hollow stud partition, especially in older houses.
- It runs along the middle of the house, parallel to the front and rear walls.
- It supports a chimney breast, water tank, or roof struts in the loft.
None of these signs is conclusive. Timber stud walls in Victorian and Edwardian houses are often load bearing, and some brick walls carry nothing at all. Previous alterations can also move loads in ways the original layout never intended. The only reliable answer comes from an engineer inspecting the building, often after lifting a floorboard or opening up the ceiling to see which way the joists run.
What the structural engineer does
The engineer’s job is to make sure the load the wall carried is safely transferred somewhere else. That usually means designing a beam to span the new opening.
Load calculation.
The engineer works out the dead loads (the weight of floors, walls and roof above) and imposed loads (people, furniture, snow on the roof) acting on the wall. These follow the Eurocodes, mainly BS EN 1990 and BS EN 1991.
Beam design.
A steel beam (often called an RSJ, though most are now universal beams or parallel flange channels), a timber flitch beam, or a concrete lintel is sized for bending, shear and deflection. Deflection limits matter as much as strength: a beam that sags too much will crack plaster and stick doors above it.
Bearings and padstones.
Each end of the beam needs adequate bearing, typically on concrete or engineering brick padstones that spread the point load into the masonry below. The engineer checks that the wall or pier underneath, and sometimes the foundation, can take the new concentrated load.
Temporary works.
The calculations normally specify how the structure is propped while the wall comes out, using adjustable steel props and needles through the wall above.
Fire protection.
Steel beams usually need protecting to achieve 30 minutes of fire resistance in a house, typically with two layers of fire rated plasterboard or intumescent paint.
The output is a set of calculations and a drawing or sketch that building control will review before work starts.
Why the engineer needs a measured survey
A structural design is only as good as the dimensions it is based on. An engineer working from a homeowner’s tape measurements or old estate agent floor plans is designing to assumptions, and assumptions are where problems start on site.
A measured survey gives the engineer and architect:
- True clear spans
, wall face to wall face, which set the beam length and bearing positions. - Wall thicknesses and pier widths
, which confirm whether there is enough masonry to bear on. - Floor and ceiling levels
, which show whether a downstand beam will clear head height or must be set flush within the floor depth. - Floor to floor heights and sections
, which reveal the depth available for the beam and any services in the way. - The layout of walls on every floor
, so the engineer can trace load paths from roof to foundation. - Openings, chimney breasts and existing lintels
, which often carry more load than expected.
It also helps beyond the structure. Architects use the survey to draw existing and proposed plans for building control, kitchen fitters order units to real dimensions, and contractors price from accurate quantities rather than guesses. Where more than one wall is changing, or you are combining rooms into an open plan space, a survey typically pays for itself by avoiding a single redesign or a beam that arrives the wrong length.
Permissions and regulations
Building Regulations.
Removing or altering a load bearing wall is building work under the Building Regulations 2010 and must comply with Part A (structure). You will need approval from your local authority building control or a registered building control approver, either through a full plans application or a building notice. Fire safety under Part B also applies: knocking through to create an open plan layout can remove the protected escape route from upper floors, which may need compensating measures such as fire doors or a sprinkler system.
Putting up new walls.
A new non load bearing stud partition usually does not need approval, but it can still affect fire escape routes, ventilation (Part F) and natural light. A new masonry wall is heavy, so the floor beneath it may need checking by an engineer.
Party Wall etc. Act 1996.
If the work involves a wall shared with a neighbour, such as cutting into it to seat a beam, you must serve notice on the adjoining owner at least two months before starting.
Planning permission.
Internal walls rarely need planning permission. The main exception is a listed building, where any internal alteration that affects its character needs listed building consent, and unauthorised works are a criminal offence.
Leasehold flats.
Most leases prohibit structural alterations without the freeholder’s written consent, which usually requires the engineer’s calculations as part of the application.
The process, step by step
- Commission a measured survey
of the affected floors, including the floor above and the loft if the wall carries roof load. - Get an engineer’s inspection
to confirm whether the wall is load bearing and trace the load path. - Receive calculations and details
for the beam, padstones, propping and fire protection. - Apply for building control approval
and serve any Party Wall notices or request freeholder consent. - Order the beam
to the surveyed span plus the specified bearing length at each end. - Prop, remove and install
, with building control inspecting the beam and bearings before they are covered up. - Get the completion certificate
, which you will need when you sell or remortgage the property.
Conclusion
If a wall is load bearing, a structural engineer is a legal and practical necessity. A measured survey is the step that makes the engineer’s design, the building control application and the contractor’s work all line up with the real building. Skipping it saves a small fee at the start and risks a much larger bill when the beam does not fit or the levels are wrong.
