Structural investigation and opening-up
A hands-on investigation where hidden structure needs to be exposed or scanned, such as lifting floorboards, opening ceilings or scanning walls, to confirm what is there before design or repair.
About this service
A structural investigation with opening-up is for situations where looking at finished surfaces is not enough. We plan and carry out targeted exposure of the hidden structure, for example lifting floorboards, cutting small openings in ceilings, removing plaster at beam ends or scanning walls, so that decisions are based on what is really there. Fees start from £900 + VAT, reflecting the extra time on site.
London's older housing makes this kind of work particularly valuable. Victorian and Edwardian houses have often been altered several times without records, and drawings from earlier projects can be missing or plain wrong. A wall that looks solid may be a timber stud partition carrying a floor, and a steel that appears to run one way may be supported by a hidden post. Finding out early avoids surprises once the builder is on site.
Our findings report includes photographs and measurements of each opening, our interpretation of the structure, and clear recommendations for design or repair. It is signed off by a chartered engineer who is a Member of the Institution of Civil Engineers (MICE). The information then feeds directly into calculations, so your design starts from fact rather than assumption, and your builder can price the work with fewer unknowns.
When you need it
- Drawings of the existing structure are missing or unreliable
- A defect needs the structure exposed to find the cause
- Your design depends on knowing what is inside walls or floors
What's included
- Planning of the opening-up locations with you or your builder
- Inspection of exposed or scanned structure
- Wall scanning and trace and access where suitable
- Findings report with photographs and recommendations
How it works
- Define the questionsWe agree exactly what needs confirming, such as joist direction, beam sizes, foundation depth or wall construction, and confirm a fixed fee in writing before planning the work.
- Plan opening-up locationsWe mark the minimum set of openings with you or your builder, considering finishes, services and access, so each one answers a specific question with least disruption.
- Expose and scanOpenings are made by your builder, or by trace and access methods where suitable, and we use wall scanning to locate steels, lintels and voids behind finishes without cutting into them.
- Record and interpretThe engineer inspects each exposure, measures members, photographs bearings and connections, and builds up a clear picture of how loads actually travel down through the building to the ground.
- Findings reportYou receive a structural investigation report with photographs, sketches and recommendations, ready to pass to your architect, designer or Building Control, and to inform the next stage of design or repair.
What you receive
Planning opening-up so it answers the right questions
Good investigations are planned around decisions, not curiosity. Before any opening is made, we ask what the design or repair depends on, then choose locations that will settle it. Making good afterwards is not included, so it helps to schedule opening-up just before a refurbishment, when finishes are being replaced anyway. In buildings constructed before 2000, consider whether an asbestos survey is needed before textured ceilings, boxing or old floor coverings are disturbed. Destructive testing of materials is outside this service.
Common outcomes include discovering that joists run the opposite way to the drawings, that a beam installed decades ago has no padstone, or that a so-called loft floor is just ceiling joists. These findings feed straight into design services such as a structural capacity appraisal or a loft conversion structural package. Our guide on loft conversion structure shows why existing joists rarely suit new floor loads.
Not included
- Making good after opening-up
- Destructive testing of materials
Frequently asked questions
What does opening up mean in a structural survey?
Opening up means exposing hidden parts of the structure so an engineer can see them directly. Typical examples are lifting floorboards to check joists, cutting a small hole in a ceiling to see a beam, or removing plaster to inspect a lintel bearing. It replaces guesswork with evidence, which is especially important for older, altered buildings.
Who repairs the holes after a structural investigation?
Making good is not included in our fee, so it is normally done by your builder, either straight away or as part of planned works. We keep openings as small and as few as possible and agree locations in advance. Timing the investigation just before a refurbishment often means the openings are covered by new finishes anyway.
Can a structural engineer find a steel beam without opening the wall?
Often, yes. Wall scanning can locate steel beams, lintels and voids behind plaster and give a good indication of position. It cannot always confirm the beam size or how it bears onto the wall, so a small opening at one end is sometimes still needed when the design relies on exact details.
Do I need an investigation before buying a property?
Usually not for a standard purchase, where a structural inspection report is enough. An investigation is worth considering if you plan major alterations immediately and need to know what the structure can take, or if a survey has found something that can only be understood by exposing it, subject to the seller's permission.