The Optimised Retrofit Programme (ORP) is the Welsh Government’s flagship initiative to decarbonise the nation’s social housing stock. Moving away from “blanket” single-measure approaches, ORP takes a data-driven, home-by-home strategy to find the most cost-effective and logical pathway to net zero for each property.
Whether you’re planning your next round of funding or trying to de-risk your installation pipeline, this guide covers how the ORP framework actually operates, how the key legal standards overlap, and how social landlords bridge the gap between theoretical energy models and real-world performance.
In this blog you’ll learn:
- Why ORP mandates complex, multi-measure, fabric-first strategies over quick single-measure fixes
- How PAS 2035, WHQS 2023 and Awaab’s Law overlap – and why a compliance lodgement isn’t the same thing as a long-term strategy
- The repeatable annual delivery cycle that sits behind every ORP funding round, regardless of the specific dates in play that year
What is the Optimised Retrofit Programme?
ORP is a whole-house, pragmatic approach to decarbonising existing homes, open to Registered Social Landlords (RSLs) and local authorities across Wales. Rather than treating insulation, heating and energy supply as separate problems, it assesses each property as one system – the fabric it’s built from, how it’s heated and stores energy, and how energy actually reaches the home – to find the specific route to net zero that fits.
The programme takes a “test and learn” approach, with a risk appetite that matches the innovative, entrepreneurial activity decarbonisation at this scale actually requires. It’s also intended to do more than fix individual homes: ORP is designed to support the wider infrastructure needed for retrofit at scale – skills development, procurement, finance models and material selection – and underpins the Welsh Government’s ongoing retrofit policy across all housing sectors, drawing on the principles set out in the Better Homes, Better Wales, Better World report.
Since its inception in 2020, the programme has invested hundreds of millions of pounds, transforming tens of thousands of homes across Wales through continuous, multi-year government funding rounds. The current phase, ORP 3, covers financial years 2026 to 2027 and continues to centre on two themes: affordable warmth and decarbonisation, alongside identifying the best pathway to better energy efficiency for each home and its residents. It’s also intended to support the Welsh Housing Quality Standard 2023 as it’s established as the new benchmark.
Source: Welsh Government, Optimised RetroFit Programme guidance, last updated 10 July 2026.
What Makes ORP Different?
Traditional grant schemes often incentivise single, isolated measures – installing solar PV or a heat pump without addressing the building’s thermal envelope. ORP rejects that approach in favour of:
- Fabric-first principles: Insulation, draught-proofing and ventilation are prioritised to reduce energy demand before complex renewable heating systems go in.
- Pragmatic sequencing: Upgrades are applied incrementally, based on what makes sense for the specific property type and tenant context.
- Local economic value: Funding criteria explicitly favour local supply chain development, job creation and upskilling within Welsh communities.
- Mandatory environmental monitoring: Performance data is collected post-installation to verify that predicted energy savings match real-world outcomes.
The Compliance Framework: PAS 2035, WHQS 2023 & Awaab’s Law
For Welsh social landlords, a compliant retrofit means managing two distinct roadmaps in tandem: a strategic goal (the Target Energy Pathway, under WHQS 2023) setting out where each property needs to end up, and an operational standard (PAS 2035:2023) translating that goal into a safely sequenced physical roadmap.
1. The Target Energy Pathway (TEP) – The Strategic Goal
Mandated under WHQS 2023, the TEP is a whole-stock modelling exercise. It establishes a property-specific route to achieving a low-carbon heating system and optimal energy performance by 2034.
- Strategic goal: The TEP is the destination, not a single grant-funded package – it’s what keeps the housing stock compliant with WHQS long-term.
Surveying every property individually to build a TEP isn’t always realistic at portfolio scale – archetyping is often the more defensible route.
Portfolio-wide PAS 2035 archetyping and costed improvement modelling, underpinning a 30-year Target Energy Pathway for 1,600 properties.
2. The Medium Term Improvement Plan (MTIP) – The Rulebook
Required under the updated PAS 2035:2023 framework, the MTIP is a 20-to-30-year operational roadmap. It translates the strategic TEP goals into safely sequenced physical stages, which are officially logged via TrustMark.
- Awaab’s Law & moisture integration: Expert damp, mould and ventilation diagnostics are mandatory under PAS 2035. Ventilation must be designed and installed before or alongside airtightness measures, to prevent trapped moisture and protect tenant health.
- Operational goal: Provides the documentation needed for TrustMark lodgement and grant drawdown.
Key takeaway: Don’t confuse a lodgement with a long-term strategy. An MTIP clears the bar for immediate funding and safe sequencing; the Target Energy Pathway is the strategic goal it’s working towards, keeping your stock legally compliant through to 2034.
Case Study: Scaled Delivery with Codi Group
As an award-winning PAS 2035 supply chain partner, we work alongside leading housing providers – including Codi Group (formerly Pobl), the largest social landlord in Wales – to deliver end-to-end Retrofit Assessment, Coordination and Design packages across complex urban and rural housing stock.
Key operational challenges addressed:
- Heterogeneous housing stock: Integrating multi-measure retrofits across a mixed portfolio – from 1950s-60s concrete flats to pre-1900 “hard-to-treat” solid stone terraces in Newport and Swansea.
- BS 40104-compliant diagnostics: Using moisture diagnostics and airtightness testing to eliminate damp and mould risks before specifying insulation measures.
- Contractor and grant governance: Managing multi-contractor compliance strictly within ORP grant limits, so every installation meets both theoretical energy performance and real-world quality control.
The Standard Annual Lifecycle of ORP Delivery
Specific application dates shift between financial cycles, but successful ORP delivery follows a repeatable annual workflow:
- Q1 (Spring) – Cycle launch & grant allocation: New ORP grant rounds are allocated; property selection begins, based on stock-wide TEP data.
- Q2 (Summer) – Assessment & moisture design: BS 40104 retrofit assessments, airtightness testing and PAS 2035 Retrofit Designs (prioritising ventilation).
- Q3 (Autumn) – Procurement & installation: Multi-measure installation on site; contractor compliance monitored against PAS 2035 standards.
- Q4 (Winter) – Lodgement & verification: Environmental sensor deployment, TrustMark Data Warehouse lodgements and annual compliance reporting to Welsh Government.
What’s Next?
Whichever stage of the annual cycle your landlord is at, the same principle holds: a PAS 2035 lodgement gets you through the funding door, but only a properly mapped Target Energy Pathway keeps your stock compliant through to 2034. We provide the evidence base behind both – independent Retrofit Coordination, moisture-safe Retrofit Design, and portfolio archetyping and modelling to underpin your Target Energy Pathway – as the bridge between securing funding and delivering it safely on the ground.
Applying for a funding round itself goes through the Welsh Government’s ORP guidance directly. Portfolio modelling and archetyping can start well before that funding is secured, though – often the evidence base a landlord needs to make the case for funding in the first place.
Get in touch with our team to discuss Retrofit Assessment, Coordination and Design for your next ORP round.
Keep Informed
Get practical insights on retrofit, decarbonisation and compliance, delivered straight to your inbox.
"*" indicates required fields