A Level 3 Survey (often called a Building Survey) is the most detailed pre-purchase survey option for residential property. You can expect it to give you a thorough, practical understanding of the building, with clear explanations of defects, their likely causes (where evidence supports this), the consequences of leaving issues unresolved, and what you should do next.
It’s designed to help you make a reasoned and informed decision—particularly where the property is older, altered, unusual, or you want the highest level of reassurance before you commit.
Below is what you can expect, step-by-step, from booking through to using the report.
1) Before the inspection: preparation and background checks
A good Level 3 Survey starts with the surveyor getting the right context. You can typically expect:
- A review of basic information provided by the estate agent or seller (property type, age, visible alterations, access notes)
- A short discussion with you about your concerns and plans (e.g., damp worries, cracking, planned refurbishment)
- Practical guidance on access (loft hatch, meters, outbuildings, keys)
This matters because Level 3 is most valuable when the surveyor understands what you need from it—whether that’s purchase reassurance, renovation planning, or risk management.
2) During the inspection: a thorough “whole building” check (within safe limits)
A Level 3 Survey involves a detailed visual inspection of the property. You can expect the surveyor to spend time assessing:
Inside the property
- walls, ceilings and floors for cracking, distortion, damp staining, or workmanship concerns
- doors and windows for alignment (movement clues), condition and ventilation issues
- bathrooms and kitchens for moisture risk indicators and visible plumbing defects
- signs of structural alteration (open-plan changes, steelwork clues, altered load paths)
The roof and high-level elements (as visible and safe)
- roof coverings, junctions, flashings and chimney condition
- rainwater goods performance (gutters/downpipes) and overflow staining
- visible roofline deflection or patch repairs
Depending on safety and access, the surveyor may use binoculars/torch and safe vantage points rather than close access to every area.
The roof space (loft), if accessible
If safe and accessible, the surveyor will inspect:
- roof structure (timbers, bracing, distortion)
- evidence of leaks or condensation in the void
- ventilation and insulation observations
- signs of wood decay risk where moisture has been present
Floors and subfloor risk (where relevant)
Level 3 surveys often give more attention to floor behaviour and subfloor conditions—particularly in older houses with suspended timber floors. Even where the survey can’t open up the structure, a good report will discuss:
- ventilation clues (air bricks, moisture pathways)
- floor deflection/bounce observations
- risk areas based on construction type and visible symptoms
External walls, grounds and boundaries
Expect the surveyor to assess:
- pointing/render condition, cracking patterns, and weathering
- damp risk factors like raised ground levels or bridging
- retaining walls, paths, steps and external movement indicators
- outbuildings and boundary elements where access is possible
3) Services: what will (and won’t) be checked
A Level 3 Survey is not a specialist test of electrical, gas or heating systems. What you can expect is:
- visual observations of accessible parts
- limited operation/observation in normal use where permitted (e.g., running taps, turning on a sample of lights, asking occupier to operate heating)
But you should also expect clear wording that the survey doesn’t replace:
- an electrical test (EICR)
- a Gas Safe inspection
- a specialist drainage check
- a full damp/timber investigation
- a structural engineer’s design-level assessment
If there are warning signs, the survey should recommend targeted follow-up checks before you exchange contracts.
4) The report: what you should receive (and how it differs from Level 2)
A more detailed description of the building
A Level 3 report should explain:
- how the property is constructed (walls, roof, floors)
- what that means for performance and maintenance
- why certain defects are more likely in that type of building
This is especially useful for older/period properties and conversions.
Defects explained with context
Instead of just listing defects, a strong Level 3 report will typically:
- identify the defect and where it occurs
- explain why it matters
- describe likely causes (where evidence supports it)
- outline consequences if ignored
- recommend sensible next steps
This is the “decision support” value of Level 3.
Repair options and priorities
You can usually expect more guidance about:
- what repairs may involve in broad terms
- what should be prioritised first (e.g., water ingress prevention vs cosmetic improvements)
- sensible timescales (urgent / short term / longer term)
Some providers can also give budget guidance where agreed—though not every Level 3 includes costings as standard.
5) Clear limitations and “unknowns”
Even the most comprehensive pre-purchase survey is still a non-intrusive inspection. You should expect the report to state:
- what couldn’t be accessed or inspected
- what was concealed or unsafe to inspect
- what that means in terms of risk
- what further investigations are recommended
This is not a weakness—it’s responsible surveying. A report that claims certainty where none is possible is the one to be wary of.
6) What you can do with the results (the practical outcomes)
A Level 3 Survey typically enables you to:
Proceed with confidence
When issues are manageable and expected for the building type.
Renegotiate with evidence
When defects are significant and supported by:
- clear survey commentary
- contractor quotes or specialist reports
Plan works intelligently
Especially if you’re renovating:
- prioritise “stop deterioration” work first (roof, gutters, damp pathways)
- avoid spending money on finishes before moisture/structure issues are addressed
- shape your project plan around how the building actually performs
Walk away early if risk is disproportionate
Sometimes the “best decision” is not proceeding—Level 3 helps you reach that conclusion before you’re committed.
7) What’s the typical timeline?
While timescales vary by provider and market demand, you can generally expect:
- the inspection to take longer than a Level 2 (because it’s more thorough)
- the report to follow after the inspection (often within days rather than instantly)
- the option to discuss the findings with the surveyor afterwards (a key value-add)
How to get the best possible Level 3 Survey
If you want to maximise value:
- tell the surveyor your specific concerns before the visit
- ensure access is available (loft hatch, keys, meter cupboards, outbuildings)
- ask for a short post-report call to go through priorities
- don’t ignore recommended follow-up checks—do them before exchange
Want help arranging the right survey for your property?
Email mail@howorth.uk or call 07794 400 212 and tell us the property type/age, whether it’s been altered, and any concerns you noticed at viewings. We’ll advise whether a Level 3 Survey is the right choice and what you should expect from the inspection and report.