Non-standard construction survey
Non-standard construction survey
Surveys for concrete, steel-frame, timber-frame, stone and system-built homes: what the construction means for condition, repair and lending.
Last reviewed 31 August 2026
What counts as non-standard construction?
Non-standard construction covers anything other than traditional masonry cavity walls with a tile or slate roof: precast reinforced concrete, steel frame, timber frame, no-fines concrete, cross-wall, stone, cob, thatch and system-built housing. A survey of such a property identifies the system where possible, assesses its known failure modes and explains the implications for repair, insurance and lending.
At a glance
- Level
- Level 3, because the construction is by definition unusual.
- First task
- Identifying the construction type and, where possible, the system.
- Lending
- Some systems are hard to mortgage; that is a lender decision, not a surveyor's.
- Designated defective
- Certain post-war systems carry a statutory designation and specific repair expectations.
Identification comes first
You cannot assess a system you have not identified. The surveyor looks at panel joints, wall thickness, eaves detail, window reveals, roof structure and any surviving markings, and compares them against known post-war and pre-war systems.
Where the type cannot be established visually with confidence, the report says so plainly and sets out what further investigation — opening up, records from the local authority, or a specialist appraisal — would be needed.
- Precast reinforced concrete: carbonation and corrosion of embedded reinforcement
- Steel frame: corrosion at frame-to-cladding junctions and around openings
- Timber frame: moisture, cavity barriers and the condition of the sheathing behind the cladding
- No-fines and in-situ concrete: thermal performance, cracking and previous overcladding
Repaired, overclad and reclassified properties
Many system-built homes have been repaired or overclad under a licensed scheme. Where that has happened, the paperwork matters as much as the building: the scheme used, whether the repair covers the whole structure, and whether certification exists.
A property that looks conventional from the pavement may still be non-standard behind the render. That is the single most common surprise in this part of the market and it usually surfaces at valuation, not at viewing.
Mortgageability and insurance
Lenders set their own policies on construction types, and those policies change. A surveyor can describe the construction and its condition, but cannot decide whether a particular lender will lend, and should not imply otherwise.
The practical route is to establish the construction first, then let your broker take the identified type and any repair certification to lenders. Buying before that is established is where transactions collapse late.
Common non-standard types and their headline issues
Indicative only. Every property is assessed on its own condition.
| Construction | Typical concern | Usual evidence needed |
|---|---|---|
| Precast reinforced concrete | Reinforcement corrosion | System identification and any licensed repair certification |
| Steel frame | Frame corrosion at junctions | Opening up or specialist appraisal |
| Timber frame | Moisture and cavity detailing | Build records, warranty, inspection of accessible frame |
| Stone and cob | Moisture movement, inappropriate repairs | Traditional-materials assessment |
Who this is for
A good fit if
- Buyers of ex-local authority and post-war system-built homes
- Owners of timber-frame or concrete houses planning work or a sale
- Anyone whose mortgage application has been queried on construction type
Not the right choice if
- Standard cavity-masonry housing in apparently reasonable condition
- Anyone needing a formal structural appraisal for a lender
- Anyone expecting a guarantee that a lender will proceed
Sequencing the checks
Do these in order and the transaction risk drops sharply.
1.Establish the construction type
Ask the agent, the seller and the local authority. Bring anything you are given to the surveyor.
Compare survey levels2.Find any repair certification
Licensed repair schemes generate paperwork. Missing paperwork is itself a finding.
Level 3 in detail3.Take the facts to your broker before you commit
Lending policy on construction type is decided by the lender, not by the survey.
What surveys cost
When to bring in a specialist
- Movement requiring calculations, monitoring design or remedial design: instruct a structural engineer.
- Suspected asbestos-containing materials: instruct a competent asbestos surveyor before any disturbance or removal.
- Electrical installations, gas, drainage and fire safety: instruct the relevant competent professional for testing and certification.
- Lease terms, title, tax and financing: your conveyancer or adviser, not your surveyor.
Common questions
Limitations and sources
- Any survey is limited to what the surveyor can see and safely reach on the day. Areas behind finishes, under floors or beneath stored belongings are not opened up.
- Identification of a system from a visual inspection is not always possible and the report will say when it is not.
- Lending and insurance decisions rest with the lender or insurer.
- Nothing on this page is a professional opinion about a specific property. KJ Surveyors has not inspected your building, and general guidance cannot replace an inspection and report.
Source: RICS · checked August 2026
Source: UK Government · checked August 2026
Source: HSE · checked August 2026
Last reviewed 31 August 2026.
Where to go next
- Level 3 — the level almost every non-standard property needs.
- period property surveys — for traditionally built, pre-war homes.
- the surveys hub — compare the three levels before instructing.
Not sure what the walls are made of?
Describe the property to KJ — age, appearance, panel lines, roof shape. KJ will suggest what to check and what the survey should confirm.
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KJ gives general guidance only and has not inspected your property. A professional opinion follows an inspection by a surveyor.