Wave 3 delivery has shifted the goalposts. Sustainability teams are now expected to deliver verified decarbonisation, EPC C uplift, fuel poverty impact, and improved indoor environmental quality — while staying inside strict spend profiles and operating under increased scrutiny from the Regulator of Social Housing and the Housing Ombudsman.

That combination creates one unavoidable reality:

Retrofit isn’t “install measures” anymore. It’s “prove outcomes”.

And the organisations that will move fastest (and defend results most confidently) are standardising a baseline-first approach.

The retrofit evidence gap nobody can fix later

Most programmes think about evidence at handover. But the most defensible evidence starts before the first measure is installed.

Wave 3 delivery windows are fixed — and if monitoring begins after the Retrofit Assessment, you’re already behind:

• your Retrofit Assessor has no pre-retrofit baseline to work from
• your funder has no M&V foundation to audit against

The most important line to remember:

Pre-retrofit baseline data cannot be recreated retrospectively.

Every week you delay is baseline data you can’t recover.

What “baseline-first” really means in Wave 3 terms

Baseline-first is a delivery discipline: you establish a pre-measure baseline, then use that baseline to generate a before/after evidence trail that your Retrofit Coordinator can sign off — and your funder can audit.

Vericon describes this as the Wave 3 Compliance Assurance Layer: Monitoring & Verification (M&V) infrastructure that proves “Least Regrets” measures work in the real world.

The approach integrates three proof streams into one evidence trail:

• Heating performance (BCM)
• Environmental quality (MultiDot)
• Electrical consumption (PowerSense)

The simplest way to think about “proof” at scale: 3 baselines

Heating baseline (carbon + EPC uplift proof)

Heating is the largest driver of housing emissions — and it’s also where “deemed savings” regularly fall apart in the real world. BCM provides visibility into heating performance and resident behaviour without needing property visits.

It’s positioned to deliver 10–18% verified reductions in heating-related gas consumption by optimising boiler flow temperatures (load compensation alignment), preventing dry-cycling, and identifying high-usage behaviours.

Just as importantly, it validates whether Wave 3-funded fabric measures are actually reducing demand post-install.

IEQ baseline (damp/mould risk + wellbeing evidence)

Healthy homes outcomes can’t be asserted — they need evidence.

MultiDot continuously monitors conditions that drive comfort, wellbeing, mould risk and fuel poverty indicators.

It’s positioned to provide early detection of damp and mould risk, and to verify ventilation performance following retrofit as part of the PAS 2035:2023 evaluation requirement.

The document also frames MultiDot outputs as ESG-ready and useful for Tenant Satisfaction Measures, Ombudsman defence (timestamped audit trail), retrofit evaluation reporting, and Awaab’s Law readiness.

Electrical baseline (heat pumps, PV, and CoP verification)

Decarbonisation requires proof. PowerSense monitors circuit-level electrical consumption to validate low-carbon heating and renewables performance.

It’s positioned to verify real-world heat pump CoP against MCS design specifications, plus PV/battery utilisation and baseline electricity consumption for planning and funding applications.

“But where does this sit in Wave 3 budgets?”

One of the strongest points in the document is how it reframes monitoring:

Instead of treating it as an operational add-on, Vericon positions POE/M&V as a capitalised project assurance tool that can be eligible within the Wave 3 “Administration & Ancillary” allocation (up to 15% of total project cost, per Scheme Guidance referenced in the doc).

It also provides indicative cost guidance for a “Sustainability pack” (BCM + 2 MultiDots + PowerSense + portal/reporting/data) at an average cost of £523.83 with 3 years’ data.

What to standardise (and what to leave “by exception”)

If you’re trying to prove outcomes across hundreds or thousands of homes, the win is not “collect more data”. The win is standardising the evidence method so it becomes repeatable and auditable:

• baseline starts before measures
• outputs map cleanly to the PAS 2035 delivery chain (RA at assessment/targeting, RC at evaluation/sign-off)
• evidence supports TrustMark / MCS workflows and compliance documentation
• data integrates into your asset/BI stack (data sovereignty, no silos)

The detailed “how” — what to baseline, how to structure evidence packs, and what your RC will actually receive — is exactly what the downloadable document is for.

Download the document: the full baseline-first evidence model (Wave 3)

If you’re mobilising a Wave 3 programme (or preparing a bid), you don’t need another retrofit overview. You need a clear evidence pathway that your funder and Retrofit Coordinator can stand behind.

Inside the PDF you’ll get:

• the Wave 3 Compliance Assurance Layer model (BCM + MultiDot + PowerSense)
• how to position M&V spend inside Admin & Ancillary headroom (15%)
• what outputs your Retrofit Coordinator receives, mapped to POE/Evaluation
• indicative pack contents and cost guidance

Optional next step: the doc also offers a free 30-minute Wave 3 Portfolio Scoping Session to map stock eligibility, model Admin & Ancillary headroom, and walk through live outputs (including joining a call with your Retrofit Coordinator).