General structural survey report (GSI)
A broader inspection of the accessible structure of a property, or a clearly defined group of areas, with a written report covering everything we find.
About this service
A General Structural Inspection report, or GSI, gives you a structural engineer's view of the whole accessible structure of a property, or of a clearly defined group of areas within it. Instead of answering one question, it looks at walls, floors, roof structure, chimneys, openings and visible foundations together, and reports on everything of structural significance that we find, good and bad.
Buyers commission GSIs when they want to understand the structure of a house before they commit, particularly older or extended properties. Owners and landlords use them when several concerns have built up in different rooms and they want one joined-up opinion rather than piecemeal advice. Developers and investors often want one before buying a property they intend to extend, convert or refurbish.
A GSI is not the same as a RICS building survey. A surveyor reports on overall condition, including damp, finishes and services. A GSI concentrates on the structure: whether it is stable, how it has moved, why it has moved and what that means for the future. Each report is signed off by a chartered engineer who is a Member of the Institution of Civil Engineers (MICE).
London's housing stock rewards a joined-up look. A typical terrace might have a converted loft, a rear extension, a removed spine wall and chimney breasts taken out at different times by different owners. Individually each change may look acceptable, but together they can redirect load in unexpected ways. A GSI pieces that history together so you can see the structure as a whole.
When you need it
- You're buying a property and want the structure checked
- There are several concerns in different parts of the building
- You want a general picture of the structural condition
What's included
- Visual inspection of the accessible structural fabric
- Assessment of cracking, movement, distortion and deterioration
- Opinion on causes and significance
- Prioritised recommendations
How it works
- Agree the scopeWe confirm whether the inspection covers the whole property or defined areas, what access is available and what the report is for. The fixed fee is confirmed in writing before any work starts.
- Desk reviewWe check what is known about the property, such as its age, construction type, past alterations, nearby trees and local ground conditions, so the site visit is targeted.
- Site inspectionAn engineer works through the accessible structure, internally and externally, recording cracking, distortion, deflection, deterioration and signs of past alterations, with photographs taken throughout the visit.
- Analysis and prioritisingWe assess the causes and significance of each issue and group our recommendations by priority, separating urgent safety items from routine repairs and longer-term monitoring.
- Report and sign-offThe GSI report is reviewed and signed off by a chartered MICE engineer and issued with photographs, ready to share with your solicitor, lender, architect or builder.
What you receive
GSI, building survey or full structural report: what fits your situation?
If you are buying a conventional house with no obvious structural concerns, a RICS building survey may be all you need, with a GSI added only if the survey flags structural issues. Where the property is older, heavily altered or shows several defects, a GSI gives you more depth on the structure. For widespread or serious movement, a Full Structural Inspection report adds a detailed defect schedule and outline remedial principles.
Typical GSI findings in London include historic settlement in bays and rear additions, roof spread where ceiling ties were cut during loft works, poorly supported chimney stacks, and floor deflection from notched joists. Many are manageable, but knowing about them before exchange can affect your negotiation. Our guide on structural reports when buying covers how to use the findings.
Be clear that a GSI is visual. It cannot see inside walls or below ground, so some recommendations may be for further investigation, such as trial pits or opening up. Build time for that into your purchase timetable if possible.
Not included
- RICS survey or valuation
- Services surveys
- Concealed defects, calculations and intrusive investigation
Projects that used this service
Frequently asked questions
What does a General Structural Inspection report cover?
It covers the accessible structural fabric of the property or the agreed areas, including walls, floors, roof structure, chimneys, openings and visible foundations. We report on cracking, movement, distortion and deterioration, give our opinion on the causes and significance, and set out prioritised recommendations. Reports start from £650 + VAT and are signed off by a chartered MICE engineer.
Do I need a GSI or a RICS survey when buying a house in London?
They do different jobs. A RICS survey reports on general condition, including damp, finishes and services. A GSI concentrates on structural stability and movement. For an older or altered house many buyers get a RICS survey first and add a GSI if structural issues are flagged, or commission both when the property already shows visible movement.
Is a GSI a full structural survey?
It is a broad visual inspection of the accessible structure with a written report, which is what most people mean by a structural survey. It does not include opening up, testing or calculations. If you need a detailed defect-by-defect schedule with outline remedial principles, our Full Structural Inspection report goes further.
Can a GSI cover just part of a building?
Yes. We can define a group of areas, such as a rear extension, a loft conversion and the ground floor openings below it, rather than the whole property. This works well for flats, mixed-use buildings or houses where the concerns are clustered. The agreed scope is set out in writing with the fixed fee.
Will a GSI tell me how much repairs will cost?
No, the report describes the defects, their causes and what type of repair or investigation is needed, but it does not price the works. If you need costs for a negotiation or budget, a separate repair cost estimate can be prepared once the scope of repairs is understood.
What access is needed for a GSI?
We need access to all rooms, the loft, any cellar or under-floor void that is safely reachable, and the exterior including the rear garden. On a purchase, the seller or agent needs to arrange this. Areas we cannot reach are listed in the report so you know what was not seen.