A Level 3 Survey (often called a Building Survey) is the most in-depth pre-purchase survey you can commission for a residential property. During the inspection, your surveyor will carry out a methodical, top-to-bottom assessment of the building’s structure and condition, looking for defects, signs of deterioration, and risks that could affect your decision to buy—or the cost and complexity of owning the property.
Unlike a quick walk-round, a Level 3 Survey is about understanding how the building is put together, how it’s performing, and what problems may be developing (including risks that can’t be fully confirmed without specialist testing or opening up).
Below is what your surveyor typically does, in the order it tends to happen on the day.
1) Prepare before arriving on site
Before the visit, your surveyor will usually:
- Review basic details: property type, approximate age, construction style, location context
- Consider likely “risk hotspots” for that building type (for example: roof junctions, damp pathways, movement history, floor types, alterations)
- Note any specific concerns you’ve raised (damp smells, cracking, recent refurb, planned works)
- Plan access requirements (loft hatch, outbuildings, meter cupboards, parking, keys)
This prep matters because Level 3 inspections are risk-led: the surveyor spends more time where the building is most likely to hide expensive issues.
2) Arrive, orientate, and check access/safety
On arrival, your surveyor will typically:
- Walk the perimeter to get an initial understanding of the building form and plot
- Identify safe access routes and hazards (fragile roofs, steep ground, unsafe voids, loose masonry)
- Confirm what they can and can’t access that day (locked rooms, blocked loft hatch, heavy storage)
A good surveyor will be transparent about limitations early, because access heavily influences what can be verified.
3) Inspect the exterior first (because the outside causes many inside problems)
A large part of a Level 3 Survey is the external envelope—because water ingress and weathering drive many of the most costly defects.
Roof coverings and roof junctions (from safe vantage points)
Your surveyor will look for:
- slipped/broken tiles or slates, patch repairs, uneven roof lines
- failing ridge/verge details, deteriorated mortar or fixings
- defects at junctions (valleys, abutments, dormers, parapets)
- signs that water may be getting in (staining patterns, moss/vegetation growth in problem areas)
Chimneys and high-level masonry
They’ll check:
- stability, leaning, cracking, open joints
- pointing condition, spalled brickwork, weathering
- flashings and chimney junction details
Rainwater goods and drainage discharge
Expect close attention to:
- blocked or leaking gutters, cracked downpipes
- poor discharge arrangements that saturate walls/ground
- staining on walls consistent with long-term overflow
External walls and openings
Your surveyor will assess:
- brickwork/render condition and cracking patterns
- pointing quality and erosion
- damp pathways such as bridged damp-proof courses, high ground levels, defective seals around openings
- window/door condition externally, including decay risk in timber elements
Grounds, boundaries and outbuildings
A Level 3 Survey doesn’t ignore the plot. Your surveyor may look at:
- retaining walls, steps, paths and patios for movement or drainage clues
- external ground levels and drainage falls (do they push water toward the building?)
- boundary walls/fences (especially if leaning/cracking)
- garages, sheds and permanent outbuildings (construction, roof condition, damp risk)
4) Move inside and inspect the structure room-by-room
Inside the property, the surveyor will systematically check the building fabric and look for patterns—because patterns often reveal cause.
Walls, ceilings and partitions
They’ll look for:
- cracking, bulging, distortion or separation at junctions
- staining or “tide marks” indicating leaks/damp
- mould/condensation risk indicators
- poor workmanship or concealed issues suggested by patch repairs
Floors and stairs
Without ripping anything up, they’ll assess:
- unevenness, slope, bounce and deflection
- localised soft spots or movement (where observable)
- signs of damp-related deterioration at low level (skirtings, wall-floor junctions)
Joinery and openings (doors/windows)
They’ll check:
- doors/windows sticking or misaligning (movement indicator)
- condensation on glazing and ventilation adequacy
- visible timber decay risk and defective seals
Kitchens and bathrooms (high-risk moisture zones)
Expect attention to:
- visible leaks/staining around fittings
- poor extraction/ventilation
- defective finishes that can hide moisture damage
- past “make-good” repairs that suggest recurring leaks
5) Inspect the roof space (loft) if accessible
If the loft is safe and accessible, this is often one of the highest value parts of a Level 3 Survey. Your surveyor will typically check:
- roof structure: timbers, bracing, distortion, alteration clues
- evidence of active or historic leaks
- condensation risk and ventilation
- insulation provision (as visible) and any adverse impacts (blocked vents, compressed insulation)
- party walls/fire breaks (where visible and relevant)
In many properties, the loft tells the “true story” of the roof, even when ceilings below look fine.
6) Consider subfloor risk and ventilation (especially in older homes)
Where the property has suspended floors or known moisture risks, your surveyor will pay attention to:
- air bricks and ventilation pathways (blocked vents are a common issue)
- moisture indicators at low level and around external walls
- whether ground levels or paving might be bridging ventilation zones
- floor behaviour consistent with decay risk (without dismantling floors)
If access to underfloor voids exists and is safe, they may be able to observe more—otherwise, they’ll assess risk based on visible evidence and construction type.
7) Review building services (observational, not specialist testing)
Your Level 3 Surveyor is not there to certify electrics/gas/plumbing, but they will:
- visually assess what can be seen (consumer unit location, visible wiring condition, pipework, visible leaks)
- comment on the apparent age and condition of systems
- operate basic controls where safe/possible (for example, running taps, checking extract fans, observing heating operation if the occupier can demonstrate)
Where services appear dated, altered, or questionable, the survey will typically recommend targeted specialist checks (EICR, Gas Safe inspection, drainage CCTV, etc.) before you commit.
8) Identify alterations, workmanship risks, and “unknowns”
A Level 3 Survey is especially good at spotting issues linked to refurbishment and structural changes. Your surveyor will look for clues of:
- removed walls / open-plan alterations
- loft conversions and extension junction issues
- inconsistent construction methods and patch repairs
- cosmetic finishes that may conceal defects (fresh plaster, isolated redecorations, boxed-in areas)
They won’t make assumptions without evidence, but they will highlight where the risk profile is higher and what to do next.
9) Flats: what changes during a Level 3 Survey?
A Level 3 Survey can still be very valuable for flats, but your surveyor’s ability to inspect the wider building may depend on access and responsibility.
During a flat inspection, the surveyor will typically:
- inspect the flat internally in full detail (as above)
- observe communal/access areas where available (stair cores, hallways, visible shared elements)
- comment on the general external condition where visible from accessible viewpoints
- highlight where building-wide information or specialist checks are needed (because many risks sit with the wider block)
This is why flats are often a “survey + solicitor enquiries” pairing: the survey addresses condition; your conveyancer confirms lease, service charge exposure, major works plans, and responsibilities.
10) Make clear what can’t be inspected (limitations)
Even a Level 3 Survey is non-intrusive. Your surveyor will not typically:
- lift fitted carpets/flooring or floorboards
- move heavy furniture or clear stored items
- dismantle services, remove fixed panels, or cut inspection holes
- test electrical, gas or drainage systems like a specialist contractor would
A good surveyor will clearly state what was not inspected and what that means for risk—so you’re not blindsided later.
11) After the inspection: what happens next?
Once the visit is complete, your surveyor will usually:
- review notes and photographs
- cross-check how observed defects relate to construction type and likely failure modes
- prioritise issues (urgent vs medium-term vs maintenance)
- set out recommended next steps (repairs, further investigations, monitoring, specialist input)
- produce a structured report that helps you decide whether to proceed and how to plan for ownership
12) How to get the best possible Level 3 Survey
If you want to maximise the value of the inspection:
- Make sure the loft hatch is accessible
- Provide keys/access to outbuildings, meter cupboards and garages
- Keep areas reasonably clear around known risk points (external walls, loft hatch, boiler)
- Tell the surveyor what you noticed on viewings (damp odour, cracks, previous leaks, recent works)
- If you’re planning works, share that too—because it changes what matters most
Want a Level 3 Survey that’s clear, thorough, and genuinely useful?
Email mail@howorth.uk or call 07794 400 212. Tell us the property type/age and any concerns (damp, cracking, roof condition, alterations), and we’ll advise on the right survey approach and what you should expect from the inspection and report.