Compartmentation surveys
A compartmentation survey checks whether the walls, floors and shafts that are meant to hold a fire in one part of a building still do. A surveyor goes into risers, ceiling voids, loft spaces and plant rooms, records every gap, unsealed pipe and missing barrier with a photo and a location, and gives you a schedule of remedial work.
Fire risk assessors often recommend one when they cannot see above ceilings or into risers. Published public contracts for a survey alone range from about £14,600 for one NHS site to £82,692 for one hospital wing.
- Sheet
- PF-01
- Subject
- Compartmentation surveys
- Scope
- England, Scotland, Wales
- Prices read
- November 2026
PF-01.1
When a survey is the right first step
- Your fire risk assessment says compartmentation could not be inspected, or recommends an intrusive survey.
- Cables, pipes or ducts have been added over the years by different trades.
- You are responsible for a block of flats that relies on stay put, so each flat must hold fire in.
- The building is higher-risk under the Building Safety Act and you need evidence for the safety case.
- You are buying, selling, refinancing or insuring a building and are asked for evidence.
- You are about to refurbish and want to know what is already broken.
PF-01.2
What compartmentation surveys cost
| Item | Published figure |
|---|---|
| Survey, one NHS site Gloucestershire Health and Care NHS Foundation Trust, May 2025, contract value as published | £14,600 |
| Intrusive surveys of two blocks, then fire stopping City of London (Barbican Estate), September 2023, contract value as published | £68,370 |
| Survey of compartment walls, one hospital wing NHS trust, Warrington Hospital, February 2025, contract value as published | £82,692 |
| Small block or single floor Usually a day rate plus a report, set once the plans have been seen | Day rate plus report |
Where these figures come from
Public contract values are the published figure on each award notice, excluding VAT where the notice says so. They show the scale of real jobs, not a rate for yours. Notices: Gloucestershire Health and Care NHS Foundation Trust, City of London (Barbican Estate), NHS trust, Warrington Hospital. As a rule of thumb, a single-block survey is priced by the day plus a reporting fee once the surveyor has seen the plans; the passive fire protection cost guide sets out what drives the price.
PF-01.3
What a thorough compartmentation survey covers
The parts of the job that decide whether it holds up in a fire.
Agreed compartment lines
A marked-up plan of which walls and floors are meant to be fire-resisting, taken from the fire strategy or worked out by the surveyor if none exists.
Access above and below
Ceiling voids, risers, loft and roof spaces, basements and plant rooms. A survey that only looks at corridors misses most breaches.
Intrusive where it matters
Lifting tiles, opening boxing and access panels, agreed in advance. Non-intrusive surveys are cheaper but will state what they could not see.
One record per defect
A reference, photo, location on the plan, the fire rating required and a recommended fix for every item, ideally with a rough cost for each.
A risk rating
Each defect ranked so the worst are fixed first, which helps when the budget does not cover everything at once.
Independence
Ask whether the surveyor will also quote for the remedial works. Many do; some clients prefer a separate firm to check the work afterwards.
Need risers, voids or a whole block surveyed? Describe the building and get a surveyor booked.
Find a contractorPF-01.4
How a compartmentation survey runs
Brief
Share the fire risk assessment, the fire strategy if there is one, floor plans and any earlier survey. Say what prompted the work and any deadline.
Plan the access
Agree which flats, offices or plant rooms need entering, how much can be opened up, and asbestos information for anything that will be disturbed.
Survey
A competent surveyor inspects the walls, floors, voids and doors in scope, opening up where needed, and records each defect with a photo and location.
Report
A defect schedule with photos and plans, ranked by risk, that a contractor can price against.
PF-01.5
Questions people ask
What is a compartmentation survey?
An inspection of the fire-resisting walls, floors and shafts that divide a building into compartments, to find gaps, unsealed service penetrations and missing barriers. The result is a schedule of defects with photographs, locations and recommended fixes.
Is a compartmentation survey a legal requirement?
No law names it, but the Regulatory Reform (Fire Safety) Order 2005 requires the responsible person to keep fire precautions in good repair, and the risk assessment must be suitable and sufficient. If the assessor could not check compartmentation, a survey is how you close that gap.
How is it different from a type 4 fire risk assessment?
A type 4 fire risk assessment is an intrusive assessment of the whole building, covering both common parts and flats. A compartmentation survey looks only at the fire-resisting structure and produces a detailed defect schedule. They are often done together. See our bulletin on type 4 assessments.
How long does a survey take?
It depends on access more than size. Risers and voids in a small block can take a day; a hospital wing or a large estate can take weeks, mostly spent arranging access to occupied rooms.
Will the surveyor open up walls and ceilings?
Only if you agree it. Intrusive surveys lift ceiling tiles and open boxing and access panels; anything more is agreed in advance and made good. Asbestos information must be checked first.
What happens after the survey?
You get the defect schedule and use it to get quotes for remedial fire stopping and compartmentation repairs. Keep the report: the next fire risk assessor will ask for it.
Find a compartmentation surveyor
Three short steps: where the building is, what the job is, and how to reach you. It takes about two minutes.
This is a free matching service, not a passive fire protection contractor. We find one who covers your area and name them to you first. Nobody contacts you until you say yes.
Thanks, your enquiry is in.
- Within one working day we will email or call to tell you which passive fire protection contractor covers your area.
- Your details reach that firm only if you say yes.
- They look at the site and give you a fixed price. No marketing from us, ever.