Scotland construction tenders: the SPD and CAS are different

A Scottish public construction tender may require a Single Procurement Document (SPD) selection response. A supplier may also hold certification against Build UK's Common Assessment Standard (CAS). Both concern prequalification evidence, but they are not interchangeable forms. The authority's published tender documents determine the selection response and what supporting evidence is accepted.

The Scottish Government's statutory guidance on selection says the SPD must be used for procurements under the Public Contracts (Scotland) Regulations 2015. Its Construction Procurement Handbook explains selection as a test of the economic operator's suitability and capacity, separately from evaluation of its project-specific tender proposal. Build UK's CAS overview describes a construction-industry organisational assessment offered by recognised bodies. A CAS certificate may support a relevant question, but it does not silently answer every exclusion, selection or contract-specific SPD field.

Start with the tender's procurement route

Read the contract notice and instructions: authority, contract scope, legal entity, procedure, selection criteria, deadlines and submission portal. Scottish public procurement is governed by its own rules. Do not import a Welsh WPPN 001 requirement or assume that a general UK industry-standard summary overrides the Scottish tender. The Scottish Procurement Journey SPD page describes the current electronic SPD modules in Public Contracts Scotland and PCS-T.

For an open procedure, selection and tender material may be submitted together but assessed separately. In a restricted procedure, selection normally precedes an invitation to tender for shortlisted candidates. The Scottish construction handbook makes that distinction. The supplier should plan evidence and deadlines according to the actual procedure, not a generic PQQ checklist.

Map CAS evidence to questions rather than attaching a badge

Create a small mapping with each SPD selection question, required answer, responsible person, evidence source and any clarification needed. A current CAS assessment may help demonstrate organisational arrangements such as health and safety management, but check the assessment body, product, level, applicant entity and currency. If the buyer asks about a particular contract role or comparable experience, answer that question on its own terms.

Never treat certification as proof that named workers, equipment or methods are right for this site. HSE's conformity-assessment guidance makes clear that third-party assessment is only one prequalification route and does not prove project-specific risk management. Our CAS buyer-verification guide covers that second-stage check.

If the authority permits equivalent evidence or asks for a self-declaration, follow its stated process. Ask a written clarification when the tender simply says “CAS required” without defining the accepted level, alternative evidence or submission route. Keep the authority's answer with the bid file. Do not buy or upgrade a provider product solely on an assumption that it replaces the SPD.

Keep an auditable bid record

Save the submitted SPD response, entity details, criterion mapping, referenced current documents, clarification answers, reviewer and submission receipt. Record any facts likely to change before award, such as insurance expiry, ownership or nominated personnel. A bid team should be able to explain which evidence supported which answer; a folder of undifferentiated PDFs is weak if an assessor needs to verify one criterion quickly.

For general industry background, use our CAS explainer. The Welsh public-works guide addresses a different devolved policy. If assessing contractor prequalification software, ask the vendor to demonstrate entity-specific evidence, criteria mapping and bid-version records. This article makes no claim that Complys submits an SPD, certifies CAS or determines eligibility for a Scottish contract.

Primary sources and integration gate

• Scottish Government — statutory selection guidance and Construction Procurement Handbook, chapter 7: Scottish selection and tender distinction.
• Scottish Procurement Journey — SPD: current electronic module route.
• Build UK — CAS and HSE — conformity assessment schemes: scope and limits of industry certification.

Before integration: Recheck the latest Scottish Procurement Journey and compare the whole live CAS and tendering owners. If either already answers the Scotland-specific SPD-versus-CAS bidder task, merge this content into that owner. Do not publish with a UK-wide claim about Scottish procurement law.