For manufacturers, fabricators, installers, and principal contractors working in Scotland, the Windows & Doors (WD3) opportunity is an early signal worth acting on. Engaging now can help you to shape requirements rather than just react to them.
LHC Procurement Group (for the Scottish Procurement Alliance) has published a prior information notice (PIN) for pre-market engagement on WD3, a proposed framework carrying forward the existing WD2 concept but with enhanced specifications, regulatory requirements and competency criteria. The estimated total value is £60m (ex VAT) across Scotland.
What’s being proposed
WD3 is currently set out as three lots:
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Lot 1: PVC-U windows and doors
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Lot 2: Timber windows and doors
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Lot 3: Aluminium-clad timber windows and doors
It is framed as a works contract (installation of doors and windows) and the engagement will seek input on scope, lotting, technical/performance requirements, competency/accreditation standards, compliance with regulatory requirements, delivery models, and opportunities for innovation.
The estimated contract notice publication date is 15 April 2026.
Delivery model expectations
A key practical point appears in each lot description: bidders must offer both design, manufacture and supply only and a complete design, manufacture, supply and installation service. Installation can be delivered through directly employed teams or supply chain members assessed and approved by the bidder. However, the appointed framework suppliers remain responsible for the full supply and installation service.
That has two implications:
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If you’re a manufacturer/fabricator, your approach to installer approval, competency assurance, and performance management will likely be scrutinised.
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If you’re an installer/contractor, your ability to demonstrate system compliance, consistent workmanship, and robust QA processes becomes central, especially where you’re partnering with manufacturers.
What “enhanced specs and competency criteria” can mean in practice
The PIN explicitly flags enhanced specs and “current and emerging regulatory requirements”. Even before the ITT is published, you can safely assume evaluators will be looking for clarity in areas such as:
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performance requirements (thermal, acoustic, durability, security) and how you prove compliance
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competence management (training records, supervision, inspection regimes, escalation)
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product traceability and change control (what happens if a component changes, or a supplier changes)
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installation QA (inspection/testing, defect management, aftercare)
It also mentions exploring innovation and potential additional workstreams such as high-performance and enhanced-security products, heritage-compliant designs, advanced glazing, emerging materials, and potentially inspection and maintenance services (noting maintenance is covered elsewhere). If any of those are part of your offer, market engagement is your chance to explain what is practical, scalable, and verifiable, without turning the framework into something only the largest suppliers can deliver.
How to make pre-market engagement work for you
This engagement is being run via written questions and optional virtual sessions, with parties invited to review and comment on draft proposals. No commercial or pricing information will be requested or evaluated as part of the exercise.
That’s helpful: it means your best contribution is how the framework should be structured and assessed so buyers get reliable delivery and suppliers can compete fairly.
A strong response typically focuses on:
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scope clarity: what should be in/out of each lot so call-offs run smoothly
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competency realism: what accreditation/competency requirements are proportionate and auditable
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delivery risk controls: what evidence genuinely predicts good outcomes (not paperwork for its own sake)
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innovation with proof: which emerging options can be specified in a way that is testable and consistent
Tender prep: a practical checklist before April
If you want to be ready when the contract notice is published, start building a “bid pack” now:
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Lot fit statement: which lot(s) you’re going after and why (capability + geography + capacity)
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Delivery model narrative: how supply-only and supply+install are resourced, governed, and quality assured
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Competency evidence: training, accreditations, installer approval processes, supervision, audit schedule
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Compliance mapping: how you evidence performance requirements and regulatory alignment (with traceable documentation)
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Case studies: a small set matched to each lot, with measurable outcomes (programme, defects, resident satisfaction, callbacks)
This is also where many suppliers benefit from a clear grasp of how call-offs work once you’re appointed. Building your approach around the realities of framework agreements can help you avoid treating award as the finish line.
How Thornton & Lowe can help suppliers compete (and win call-offs)
Construction and building works frameworks can be unforgiving: a strong operational business can still lose marks if the submission doesn’t make compliance, competence and QA easy to verify.
Thornton & Lowe helps suppliers turn technical delivery models into evaluator-friendly responses. We can support by sharpening win themes, aligning evidence to scoring, and applying robust quality assurance so the bid is clear, compliant and persuasive. Support through our bid writing services is particularly valuable where competency criteria, governance and evidence structure drive the final score.
Next steps for suppliers
Start by reading the Windows & Doors (WD3) notice on Find a Tender and deciding which lot(s) genuinely match your product and delivery model. It helps to plan out how you will approach lot strategy, evidence gaps, and how to present competency and QA in a scoreable way. If you want a second pair of eyes, Thornton & Lowe can help you move faster and bid with more confidence before the ITT lands.
