SSIP, CHAS and Constructionline: what contractor schemes prove

Updated 23 October 2026 · SEO Dons Editorial

These schemes answer a narrow question: has this company shown, on paper, that it manages health and safety and, at higher tiers, that its insurance and corporate records are in order? That is a useful filter. It is not a reference for roofing workmanship, and the scheme owners say as much. This guide covers what each scheme checks, what it leaves out and how to verify a certificate. Schemes are one part of vetting a commercial flat roofing contractor.

How do SSIP, CHAS and Constructionline relate?

SSIP (Safety Schemes in Procurement) is an umbrella body. It says it does not carry out assessments directly: its members do. CHAS describes itself as a founder member of SSIP, and Constructionline says its SSIP certificates come through Once For All Health & Safety, which is a member. Every member scheme assesses against the same SSIP core criteria, which SSIP says makes the assessments equal.

Mutual recognition, which SSIP calls Deem to Satisfy, lets a contractor assessed by one member scheme use that certificate to meet another scheme's requirement without a full second assessment. For a client the useful result is that data from all completed assessments is visible on the SSIP Portal, so one search by company name shows what a firm holds.

What do SSIP assessments actually check?

The core criteria are the threshold standard. The scheme reviews what the contractor submits against each area:

Area	What the scheme looks at
Policy	A suitable health and safety policy, with a statement of intent signed by the managing director or equivalent and dated within the previous 12 months.
Competent advice	An appointed adviser with sufficient training, experience and knowledge; for construction, specific knowledge of CDM 2015.
Training	Records showing training is in date, appropriate and proportionate to the risk of the work.
Accident and enforcement history	RIDDOR statistics, a breakdown of HSE prosecutions or enforcement over the previous 5 years, and a check against the HSE register of convictions and enforcement notices.
Sub-contracting	Whether and how the firm appoints sub-contractors and consultants, and how it monitors them.
Safe systems of work	Documented risk assessment and method statement procedures; a principal contractor or sole contractor on site must supply an example construction phase plan.

What do CHAS's levels add?

CHAS says it offers three membership levels. Standard is a health and safety assessment that meets SSIP, Advanced adds the former PAS 91 questionnaire, and Elite covers the Common Assessment Standard, which CHAS says spans 13 areas of risk management.

Two details matter when you read a CHAS record. CHAS describes a full desktop assessment as an assessor's review done remotely, without any site visits, and a separate CHAS Assured on-site audit that samples live documents on site; ask which one the contractor holds. It also describes the insurance module in CHAS Standard as self-certified, so ask for the insurance certificate itself. CHAS says assessments are carried out once a year.

What does Constructionline add?

Constructionline describes four membership levels. Bronze lets a supplier manage insurance and SSIP data through a simplified question set. Silver shares compliance and SSIP data with buyers. Gold adds the Common Assessment Standard, and Platinum adds a one day premises audit. Constructionline also says it conducts verification checks for all the suppliers on its platform. Because the evidence differs by level, check which level a firm holds and what was verified.

The descriptions in this section and the last concern safety, insurance, finances and corporate standing. None of them mentions workmanship on a particular roof system.

What happened to PAS 91?

PAS 91 was a standard prequalification questionnaire for construction. Constructionline says BSI withdrew it in 2023, and BSI's own record for PAS 91:2013+A1:2017 shows it as withdrawn on 21 April 2023. CHAS now calls it the former PAS 91 and describes the Common Assessment Standard, backed by Build UK and the Civil Engineering Contractors Association, as the construction industry's benchmark for prequalification, while noting that some clients still recognise PAS 91 and may ask for it.

What do these schemes not prove about roof work?

Safety only, for SSIP. The SSIP Forum notes that mutual recognition arrangements relate only to health and safety.
Building Regulations competence. SSIP's own criteria page says additional standards are required to demonstrate competence and compliance with the Building Safety Act and secondary legislation, that is the Building Regulations.
Project-specific capability. The SSIP Forum reproduces HSE's message that a member certificate cannot on its own be taken as sufficient assessment of organisational capability to start work on site, and that clients should carry out project-specific scrutiny of skills, track record and capability.
A legal requirement. The same page states that legislation does not require a third party prequalification assessment.

Pair scheme records with the trade and insurance checks in how to choose a commercial flat roofing contractor. The roofing trade schemes are explained on the accreditations page, and the system certificate is covered in how to check a BBA certificate.

How do you verify a scheme certificate?

Ask for the exact legal name and the certificate or membership number, and confirm they match the company that will sign the contract.
Search the SSIP Portal by company name to see which member scheme holds the assessment.
Check the SSIP category or CDM dutyholder role assessed, because SSIP says an assessment must cover the category relevant to the business, and check the expiry date.
For CHAS or Constructionline, confirm the level and whether the audit was desktop or on site.
Ask for the live documents behind the record: current insurance certificate, the risk assessment and method statement for this roof, and a draft construction phase plan.
Make the project-specific check that HSE's message to clients describes, then move to the contract terms in JCT contracts, retentions and defects periods.

Sources

SSIP core criteria, SSIP (checked 22 October 2026).
View from the Health and Safety Executive, SSIP (checked 22 October 2026).
Frequently asked questions, SSIP (checked 22 October 2026).
Do you need a certificate?, SSIP (checked 22 October 2026).
Deem to Satisfy, SSIP (checked 22 October 2026).
Clients, SSIP (checked 22 October 2026).
CHAS home page, CHAS (checked 22 October 2026).
Health and safety assessment (CHAS Standard), CHAS (checked 22 October 2026).
Common Assessment Standard, CHAS (checked 22 October 2026).
PAS 91, CHAS (checked 22 October 2026).
About Constructionline, Constructionline (checked 22 October 2026).
Sub-contractor memberships, Constructionline (checked 22 October 2026).
SSIP with Once For All Health & Safety, Constructionline (checked 22 October 2026).
PAS 91 pre-qualification questionnaire, Constructionline (checked 22 October 2026).
PAS 91:2013+A1:2017 Construction prequalification questionnaires (withdrawn), BSI (checked 22 October 2026).
CDM Regulations 2015, regulation 8, legislation.gov.uk (checked 22 October 2026).

Common questions

Is SSIP accreditation a legal requirement for a roofer?

No. The SSIP Forum reproduces HSE's message that legislation does not require a third party prequalification assessment, and calls it one way of meeting prequalification standards. CDM 2015 still requires a client to take reasonable steps to satisfy themselves of a contractor's competence.

Are CHAS and SSIP the same thing?

No. SSIP is the umbrella body and does not assess contractors itself. CHAS is a member scheme that also sells higher assessments, such as the Common Assessment Standard, which go beyond the health and safety remit of SSIP.

How often is a scheme assessment repeated?

CHAS says assessments are carried out once a year and that members must update time-critical documents, such as insurance certificates, when they expire. Check the dates on the record rather than assuming a badge is current.

Does a higher Constructionline or CHAS level show a better roofer?

It shows more of the same kind of evidence, such as the Common Assessment Standard or a premises audit. These cover safety, insurance, finances and policies, so they do not replace a check of the roof system, installer approval and comparable work.