A Level 3 Survey (often referred to as a Building Survey) is the most detailed type of RICS home survey. It’s designed for situations where you need deeper technical insight into the structure and fabric of the building—especially where the risk of expensive surprises is higher.
RICS’ own guidance suggests Level 3 when you’re dealing with a large, older or run-down property, a building that is unusual or altered, or if you’re planning major works.
If that sounds like the property you’re buying (or the way you intend to use it), Level 3 is often the most sensible choice.
Why buyers choose Level 3
Most buyers don’t choose Level 3 because they want a longer report—they choose it because they want:
- More detail on how the property is built, and what that means for performance and maintenance
- Stronger guidance on defects, likely causes, and repair implications
- A clearer view of risk, including the risk of issues in areas that couldn’t be inspected
- Help planning renovation or major works with fewer nasty surprises
RICS describes Level 3 as giving detailed information about the structure and fabric of the property and being more extensive than Level 2.
When Level 3 is usually the right choice
1) The property is older, large, or in poor condition
If the property is visibly tired, has long-standing maintenance issues, or is simply older with “layers” of historic repairs, Level 3 is often a better fit. RICS explicitly links Level 3 to large, older or run-down properties.
Typical signs that push you toward Level 3:
- roof coverings nearing end of life, staining, or patch repairs
- widespread damp indicators (mould, blown plaster, repeated redecorating)
- uneven floors, sticking doors, pronounced cracking
- obvious DIY or inconsistent refurbishment
- poor external maintenance (guttering, pointing, render)
2) The building is unusual or non-standard
If the property isn’t a straightforward “typical” construction, a deeper survey is usually wise. RICS guidance flags Level 3 for buildings that are unusual.
This might include:
- uncommon wall/roof construction for the area
- complex roof shapes, large areas of flat roof, or awkward junctions
- basements/cellars, significant retaining walls, or substantial level changes in the plot
3) The property has been significantly altered
Alterations can be perfectly fine—if done well—but they also create unknowns. RICS points Level 3 at buildings that are altered.
Examples where Level 3 often makes sense:
- open-plan knock-throughs or removed internal walls
- major extensions (especially where new and old structures meet)
- loft conversions (structural changes, insulation/ventilation complexity)
- “developer refurb” where finishes can hide defects
4) You’re planning major works after purchase
If you’re intending to extend, reconfigure layouts, or undertake major refurbishment, Level 3 is designed for that situation. RICS explicitly includes “planning major works” as a reason to choose Level 3.
This is one of the most overlooked points: even if a property looks acceptable today, your planned works may expose issues you’d rather understand before you commit.
What Level 3 gives you that Level 2 doesn’t
Both Level 2 and Level 3 are visual surveys (not destructive investigations), but Level 3 goes further in detail, interpretation, and repair guidance.
Deeper description of construction and materials
RICS states that Level 3 reports describe the form of construction and materials used for different parts of the property.
That matters because it helps you understand how the building should behave (and be maintained), rather than just listing defects.
More on defects: cause, repair scope, and consequences
RICS guidance says a Level 3 report should:
- describe the identifiable risk of potential or hidden defects in areas not inspected
- propose the most probable cause(s) of defects based on the inspection
- outline the likely scope of remedial work and explain consequences of non-repair
- make general recommendations on priority and timescales for necessary work
That “so what?” piece is where Level 3 often earns its keep for higher-risk properties.
A more extensive inspection approach (within safe limits)
RICS notes that Level 3 includes a detailed visual inspection and is “more extensive than Level 2.”
It also confirms that concealed areas normally opened/used by occupiers may be inspected where safe (roof spaces, basements, cellars).
Services observed in normal operation (but not tested)
With Level 3, services aren’t technically tested, but they are observed in normal operation—i.e., operated where safe and where permission is given.
Possible cost indications (if agreed)
RICS also notes a Level 3 surveyor may provide an estimate of costs for identified repairs if agreed with you in advance.
When Level 3 may be more than you need
If the property is conventional, simple in layout, and in reasonable condition, a Level 2 Survey is often the better value choice. RICS describes Level 2 as most suitable for conventional properties in reasonable condition and simple form/layout (e.g., not multiple alterations/extensions).
RICS also states Level 2 is aimed at reporting on the condition of the main elements and it will not contain detailed advice on repairs.
So if your property is a fairly standard build with no obvious red flags and no big renovation plans, Level 2 can provide the reassurance you need without paying for extra depth you may not use.
A quick self-check: do you need Level 3?
If you tick two or more, Level 3 is usually the safer choice:
- The property is older or clearly “character/period”
- It looks run-down, neglected, or has patch-repair history
- It has been altered (extensions/loft conversion/open-plan changes)
- It’s unusual in design or construction
- You’ve noticed damp, cracking/movement, roof concerns, or recurring repairs
- You’re planning major works soon after purchase
The sensible middle ground if you’re unsure
If you’re on the fence, the best approach is to decide based on risk and consequence:
- If you’d be financially or emotionally stressed by a surprise £10k–£30k repair, choose Level 3 to reduce uncertainty.
- If you’re comfortable with standard maintenance risk and the property is conventional and tidy, Level 2 is often enough.
Want a clear recommendation for your purchase?
Email mail@howorth.uk or call 07794 400 212 and tell us the property type/age, whether it’s been extended or altered, and any concerns you noticed on viewings (damp, cracking, roof condition). We’ll guide you on whether a Level 3 Survey is the sensible choice—or whether a Level 2 will do the job.