Structure
What does non-standard construction mean in a home survey?
RICS aims Level 1 and Level 2 at conventional homes built from common materials. Level 3 is the survey they describe for older, altered or unusual construction. Non-standard is not one defect, and it is not automatically a reason a lender must refuse. Lenders set their own criteria. This page does not invent them.
Last reviewed 24 October 2026. Written for buyers in England and Wales unless a source says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.
What does RICS mean by a conventional home?
The consumer guide points Level 1 and Level 2 at houses, flats and bungalows built in a common way, from materials a surveyor sees every week, and not full of alterations. That is a scope decision. It is not a moral judgment on any other way of building. If the walls, the frame or the floors are not that ordinary construction, the inspection Level 2 assumes can be the wrong tool.
Level 3 is where RICS says the surveyor describes how that particular building was put together. You want that description in writing: solid brick, cavity, timber frame, concrete panels, or “could not tell because of the lining”. “Non-standard” on its own is a label, not a specification.
What can a visual survey actually identify?
The surveyor looks at what is exposed: wall thickness, lintels, roof structure if they can enter the void, and the way junctions are finished. Linings, render and later insulation hide the original system. A Level 1 does not open the fabric. Neither does Level 2 or 3 as standard. If the report says the construction could not be confirmed, that uncertainty is the finding.
- Ask which elements they could see and which they inferred.
- Ask whether the roof void, the eaves and a lifted hatch changed the conclusion.
- Ask what further opening-up, if any, they want before you commit.
Does unusual construction mean you cannot get a mortgage?
No. Some lenders are comfortable with some systems and not with others, and they change their minds. That is their credit policy, not a sentence in the Home Survey Standard. Do not let an agent tell you a label is fatal, and do not let a forum tell you it is always fine. Ask the lender you intend to use, and give them the surveyor’s description of the construction, not a nickname.
What should you do when the report uses this phrase?
Get the construction named. If the surveyor recommends Level 3 and you only have Level 1, that is a scope problem, not a reason to panic-buy a specialist you do not understand. If they recommend a specialist report on a named system, ask what question that report is meant to answer. Repairs, if any, follow the defect, not the category.
Common questions
Is a concrete house always non-standard?
Concrete was used in many different systems, some ordinary and some not. The survey should say what it could see. A label from a listing is not an identification. Do not assume a repair scheme or a lender’s historic list still applies until someone competent has named the system.
Is modern timber frame a problem?
Modern timber frame, built as such, is a known method. The survey still has to see whether the frame, the cladding and the cavity are doing what they should, including keeping water out. “Timber frame” is not, by itself, a defect or a compliment.
Should unusual construction always be a Level 3?
RICS describes Level 3 for unusual construction. That is the starting point for the instruction. A surveyor who has already seen the building may still explain why a different level was enough. Ask them to write that reason down.
Does non-standard construction mean asbestos?
No. Asbestos can be in ordinary houses built or refurbished before 2000, and it can be in system-built ones. The questions are separate. Do not drill either to find out.
Will insurance be refused?
This page does not know. Insurers set their own acceptance. Tell them the construction the survey names, not a vague phrase. A refusal from one insurer is not a survey finding.
Does the survey value a non-standard house?
Only if you instructed a valuation. Level 3 is not automatically a valuation. A lender’s valuation is a third document. None of them is a quote for repairs.
Should you open the wall before exchange?
Only if the surveyor has said the unseen part matters to the decision, and the seller agrees. Opening up is damage. It is sometimes the only way to stop guessing. It is not a ritual for every unusual house.
The agent says it is standard brick. Who is right?
The person who inspected the fabric, if they say what they saw. An agent’s description in the particulars is not an inspection. If they disagree, ask the surveyor which detail convinced them.
Sources
Key facts
- Level 1 and 2
- Described by RICS for conventional homes of common materials, in good or reasonable condition.
- Level 3
- The level RICS describes for older, run-down, unusual or heavily altered buildings, or if you plan major work.
- Not one system
- Timber frame, steel frame, concrete panel and other systems are different. The survey should name what it could see.
- Lending
- A lender’s rules are theirs. This page does not list systems as unmortgageable.