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Compartmentation Survey

Compartmentation Surveys — Type 2 and Type 4 intrusive inspections with photographic, location-referenced reports

We carry out compartmentation surveys for higher-risk buildings, residential blocks, schools, care homes and commercial premises across Bedfordshire, Hertfordshire and London. Every survey is referenced against the building's fire strategy drawings, recorded with photographic and location-specific evidence, and structured to support the golden thread of information required under the Building Safety Act 2022.

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SSAIB Certified
Fast Response Times
15+ Years Experience
500+ Commercial Clients

Who is this for?

For responsible persons, accountable persons, building safety managers, principal designers, managing agents, freeholders and main contractors who need to evidence the integrity of compartmentation in their buildings.

  • Higher-risk buildings (HRBs) over 18 m or 7 storeys under the Building Safety Act 2022
  • Residential blocks, purpose-built flats and HMOs needing Type 4 intrusive fire risk assessments
  • Schools, academies and colleges — particularly in roof voids, risers and ceiling voids
  • Care homes, hospitals and NHS estates with progressive horizontal evacuation strategies
  • Commercial offices, multi-tenant buildings and shopping centres
  • Hotels, student accommodation (PBSA) and serviced apartments
  • New-build handover surveys and Regulation 38 compliance packs for principal contractors
  • Refurbishment, fit-out and post-works compartmentation verification

Common compartmentation failures we identify

  • Unsealed service penetrations — cables, pipes, ducts and trays passing through fire-rated walls and floors with no certified firestopping system in place
  • Breached compartment lines in roof voids, ceiling voids and risers that allow fire and smoke to bypass the building's fire strategy entirely
  • No fire strategy drawings, no firestopping register and no record of who installed what — leaving the responsible person unable to evidence the golden thread under the Building Safety Act
  • Recent works — IT cabling, M&E upgrades, partition changes — that have created new penetrations without the original firestopping being reinstated
  • Cavity barriers missing or incorrectly fitted in timber-frame, SIPS and modular buildings, allowing concealed fire spread within the structure
  • Fire damper failures or missing dampers at duct penetrations through compartment lines
  • Risers, lift shafts and stairwells with breaches at floor-by-floor compartment interfaces

What's included in our compartmentation survey

Pre-Survey Document Review

We review your fire strategy, architect's drawings, Regulation 38 information, O&M manuals and any previous compartmentation reports before we attend site, so we arrive with the expected compartment lines marked up.

Type 2 or Type 4 Inspection

Type 2 surveys are non-intrusive inspections of common areas and accessible compartment lines. Type 4 surveys are intrusive — opening ceiling tiles, lifting access panels, inspecting risers and roof voids, and sampling flat or room interiors. We scope to whichever the building's risk profile requires.

Service Penetration Audit

Every penetration through a fire-rated element is logged, measured and assessed against tested third-party systems (FIRAS, IFC, BM TRADA). We identify which are compliant, which need remedial work, and which are missing entirely.

Compartment Line Verification

We trace and verify each compartment wall and floor against the fire strategy — including stairwells, lift shafts, risers, plant rooms and flat entrance lines — and flag any breaches in the line of fire resistance.

Cavity Barrier & Void Inspection

Concealed spaces — ceiling voids, floor voids, raised access floors, roof voids, external cavities — are inspected for cavity barriers and continuity of fire and smoke separation.

Photographic & Location-Referenced Report

Every finding is photographed, given a unique reference number, plotted on a floor plan and risk-rated. The report drops straight into your golden thread of building safety information — not a generic PDF you have to interpret.

Scope of works

Our qualified engineers carry out the following as standard:

Review of fire strategy and Regulation 38 design information
Visual inspection of all accessible fire-rated walls, floors and ceilings
Intrusive inspection of ceiling voids, risers and roof spaces (Type 4)
Audit of every service penetration through a compartment line
Verification of cavity barriers in concealed spaces
Inspection of fire-resisting ductwork, dampers and shaft linings
Review of flat entrance and cross-corridor doors as compartment elements
Cross-reference of installed firestopping against tested third-party systems
Risk rating of each defect (immediate / short / medium term)
Marked-up floor plans showing every defect location
Photographic register with unique IDs for every finding
Schedule of remedial works with indicative quantities for pricing

Need to evidence compartmentation for your insurer or the Building Safety Regulator? Book a survey today.

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Optional services

Certified Remedial Fire Stopping

We carry out the remedial works ourselves using third-party tested and certified systems, with installer certification issued on completion — no need to coordinate a separate contractor.

Firestopping Register & Asset Tagging

We can install a labelling and asset-tag system at every penetration, linked to a digital register, so future maintenance teams know exactly what is installed and how to reinstate it correctly.

Pre-Handover Regulation 38 Survey

For new build and major refurbishment, we survey the building before handover, identify any non-compliances and produce the Regulation 38 fire safety information pack required at completion.

Re-Inspection & Sign-Off

After remedial works are complete — by us or by others — we return to verify, photograph and sign off that the compartmentation has been restored to the original fire strategy.

Fire Door Surveys (BS 8214)

Compartmentation surveys are commonly bundled with fire door surveys as flat entrance and cross-corridor doors form part of the compartment line. We can deliver both in one mobilisation.

Fire Risk Assessment (PAS 79:2020)

Where the compartmentation survey forms part of a wider Type 3 or Type 4 fire risk assessment, we can deliver the full PAS 79:2020 assessment alongside it.

Typical project timeframes

Small commercial / single block (up to 1,500 m²)1–2 days on site
Mid-size building (1,500–5,000 m²)3–5 days on site
Large estate or HRB (5,000 m²+)1–3 weeks on site
Report turnaround10 working days from final visit
Remedial works mobilisationFrom 2 weeks subject to access

Key benefits

Aligned with the Building Safety Act 2022 and the golden thread of information
Type 4 intrusive surveys — the level of inspection most insurers and fire authorities now expect
Photographic evidence and unique reference IDs for every finding
Marked-up floor plans, not just a list of locations
Risk-rated defect schedule (immediate / short / medium term) ready to price
Compatible with FIRAS / IFC remedial frameworks for any installer
Single provider option — survey + remediation in one accountable contract
Reports formatted to feed directly into your building safety case

Ongoing support & maintenance

Annual Re-Inspection

We return on an agreed cycle to re-survey high-risk areas — typically risers, plant rooms and recently-accessed voids — and update your firestopping register.

Reactive Reinstatement

When other trades break a compartment line during M&E or fit-out works, we attend, reinstate the firestopping with a tested system and update the register so the golden thread stays intact.

Single Point of Accountability

Survey, remedial works, certification and re-inspection from one company — so there's no gap between the contractor who identified the breach and the contractor who closed it.

Toolbox Talks for Site Teams

We deliver short on-site toolbox talks for principal contractors and FM teams so the people drilling holes understand why and how compartmentation must be reinstated.

How it works

01

Scoping Call

We talk through the building, the trigger for the survey (insurer, BSR, fire authority, refurb, sale) and confirm whether a Type 2 or Type 4 inspection is appropriate.

02

Document Review

We review the fire strategy, architect's drawings, Regulation 38 information and any previous compartmentation reports before attending site.

03

On-Site Survey

Our surveyors carry out the inspection — opening ceiling tiles, accessing risers and voids where authorised, photographing and recording every finding against the floor plan.

04

Reporting

We compile the executive summary, technical report, photographic register and remedial schedule. Reports are delivered within 10 working days of the final site visit.

05

Optional Remedials & Sign-Off

Where instructed, we mobilise our installation teams, complete the remedials using certified systems, and re-inspect to confirm compartmentation has been restored.

Case study
Case Study

Type 4 intrusive compartmentation survey across a 6-storey residential block

Residential block — managing agent, North London

Scale48 flats, 6 storeys
DurationSurvey 2 weeks, report 10 working days
OutcomeInsurer evidence pack accepted first time
Challenge: Following a building insurance review, the managing agent was required to evidence the integrity of compartmentation in a 1990s purpose-built block of 48 flats. There was no firestopping register, drawings were incomplete and previous M&E works in the risers had not been signed off.
Solution: We carried out a Type 4 intrusive survey across all common areas, risers, roof voids and a sample of flat entrance interfaces. Every penetration was photographed, given a unique ID and plotted on marked-up floor plans. We then issued a fully priced remedial schedule covering 134 non-compliant penetrations.
Insurer evidence pack accepted first time
134 non-compliant penetrations identified
Marked-up floor plans for every level
Building safety case updated with golden thread evidence

Frequently asked questions

What is the difference between a Type 2 and a Type 4 compartmentation survey?
A Type 2 survey is a non-intrusive visual inspection of common areas and accessible compartment lines. A Type 4 survey is intrusive — ceiling tiles are lifted, access panels are opened, risers and voids are inspected and a sample of flat or room interiors is included. Since the Building Safety Act 2022 and the post-Grenfell rebalancing of fire risk assessment guidance, Type 4 surveys have become the expected standard for higher-risk residential buildings and any premises where the integrity of hidden compartmentation cannot otherwise be evidenced.
What does the Building Safety Act 2022 require for compartmentation?
For higher-risk buildings (broadly, residential buildings 18 m or 7 storeys and above), the Accountable Person must build and maintain a 'golden thread' of building safety information, including evidence that compartmentation and fire stopping perform as the fire strategy intends. In practice this means an accurate firestopping register, photographic evidence of compliant installations, a record of who installed what to which tested system, and a re-inspection regime when the building changes. By 2026 the transitional periods have ended and these requirements are fully enforceable by the Building Safety Regulator.
How is a compartmentation survey priced?
Pricing depends on the building's size, complexity, the level of intrusion required (Type 2 vs Type 4) and access constraints. As a guide, a non-intrusive Type 2 survey of a standard 2,000 m² office is typically in the £1,200–£2,500 range. Larger or more complex buildings — hospitals, residential blocks, multi-tenant estates — are priced on a per-day or per-square-metre basis after a brief scoping call. Remedial fire stopping works are priced separately and depend on the number, size and substrate of the penetrations identified.
Will the survey disrupt occupants of the building?
We plan surveys around occupancy. In residential blocks we work in common areas, risers and a pre-agreed sample of flats with prior notification. In schools we work during holidays or out of hours where possible. In offices and hospitals we phase the inspection around clinical and operational priorities. All openings are made good after inspection unless remedial works are immediately authorised.
Do you produce marked-up drawings or just a written report?
Both. Every finding is photographed, given a unique reference number, plotted on a floor plan provided by the client (or generated from a site sketch where drawings are unavailable), and risk-rated. The combination of marked-up drawings, photographic register and risk-rated schedule is what most insurers, fire authorities and the Building Safety Regulator now expect.
Can you carry out the remedial fire stopping works as well as the survey?
Yes — and most clients prefer this. A single contract from survey through to remediation and sign-off removes the gap between the firm that found the defect and the firm that closes it. Our schedule of works is structured so you can also tender the remedials separately to any FIRAS or IFC contractor — we are happy to support either route.
How does this work alongside a fire risk assessment?
A compartmentation survey is often the technical evidence that underpins a Type 3 or Type 4 fire risk assessment. The fire risk assessment under the Regulatory Reform (Fire Safety) Order 2005 considers fire safety holistically — escape routes, alarms, management — while the compartmentation survey gives the assessor the hard evidence that the passive fire protection still works. We can deliver both as a combined package, or feed our compartmentation report into a fire risk assessment your existing assessor is producing.
What about cavity barriers in timber-frame and modular buildings?
Concealed-space cavity barriers are a significant risk area — particularly in timber-frame, SIPS, modular and refurbished buildings. Our Type 4 survey explicitly inspects roof voids, ceiling voids, floor voids, external cavities and party wall interfaces for cavity barrier presence and continuity. Where barriers are missing or incorrect we record the location and substrate so the remedial system can be selected against the construction type.
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24-hour response
SSAIB certified
500+ commercial clients

What happens after you contact us

1

We review your enquiry

A member of our team reviews your requirements and gets back to you within 24 hours.

2

We arrange a site survey

We schedule a convenient time to visit your site and assess your needs in person.

3

We prepare a quotation

You receive a clear, detailed quote with no hidden costs or obligations.

4

We schedule the work

Once approved, we agree a start date that works around your operations.

5

We provide documentation & support

On completion, you receive all certificates, reports, and ongoing support details.

Commercial Clients

Trusted by schools, care homes, warehouses, and construction sites

We work with commercial and public sector clients across Bedfordshire, Hertfordshire, Buckinghamshire, and London.

Schools & Academies

Primary schools, secondary schools, multi-academy trusts, and nurseries

Construction Sites

Active building sites, developments, and temporary site compounds

Warehouses & Industrial

Warehouses, distribution centres, factories, and industrial units

Care Homes & Healthcare

Care homes, nursing facilities, clinics, and GP surgeries

Car Garages & Workshops

MOT centres, car dealerships, vehicle workshops, and body shops

Commercial Offices

Offices, business parks, co-working spaces, and corporate HQs

Public Sector

Local authority buildings, NHS facilities, and community centres

Retail & Hospitality

Shops, restaurants, pubs, hotels, and leisure venues

Areas we cover

LutonBedfordSt AlbansWatfordStevenageMilton KeynesHemel HempsteadHitchinDunstableBarnetLondon

Related services

Fire Stopping Fire Risk Assessments Fire Door Inspections Fire Door Remedials Compliance Packages School Fire Compliance

Book a compartmentation survey

Evidence the integrity of your compartmentation, build out your golden thread of building safety information, and get a priced remedial schedule ready to issue. Contact us for a scoping call and a fixed-price proposal.

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24-hour response
SSAIB certified
500+ commercial clients