PAS 2035 · Level 5 Retrofit Coordination · London & South East

Funded, compliant, clawback-proof retrofit programmes.

Nanox Energy helps housing providers, local authorities and contractors deliver PAS 2035-compliant retrofit, from the first energy audit and funding bid through to TrustMark lodgement. Engineer-led coordination means your board gets certainty, your residents get warmer homes, and your funders get full compliance.

Book a free 30-minute scoping call See our project results
7
Projects & studies delivered
276+
Buildings assessed
Up to 100%
On-site fossil fuel elimination
2,600+
Lifetime tCO₂e savings identified
What we do

Six services. One point of accountability.

From the first heat-loss calculation to final lodgement, we cover the full retrofit lifecycle, so nothing falls between consultants, and nothing puts your funding at risk.

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Retrofit Coordination

End-to-end coordination of domestic retrofit in line with PAS 2035: risk pathways, whole-dwelling assessment, improvement plans, design coordination and TrustMark lodgement.

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PAS 2035 Support

Gap analysis, audit-readiness reviews, specification checks and defect investigation for contractors, housing associations and installers who need PAS 2035:2023 confidence.

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Energy Audits

Investment-grade energy surveys: metered consumption analysis, U-value and heat-loss calculation, and a costed, ranked table of measures ready for board approval.

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Decarbonisation Plans

Site and portfolio roadmaps that sequence fabric, heating and renewables correctly: heat pumps sized against the improved fabric, phased pathways to net zero.

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Funding Support

We turn technical plans into fundable applications, structured around the metrics funders score: £/tCO₂e, payback, deliverability and co-benefits.

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Programme Delivery

Client-side programme management at scale: procurement support, quality-assurance regimes, site inspections, resident liaison and progress reporting.

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Featured case study

PAS 2035 quality review: 270 traditional homes, North Wales

External wall insulation on solid-wall housing in Exposure Zone 4 (very severe) is one of the highest-risk retrofit measures in the UK. Across a 270-property scheme, recurring defects were putting performance, durability and compliance at risk: render discolouration, thermal bridging, cold spots around openings, and water-ingress pathways at sills and flashings.

We carried out a systematic defect review across the portfolio, benchmarked every failure class against INCA best practice and the system designer's installation requirements, and traced consequences through to resident impact: heat loss, condensation risk and mould.

The value: on a 270-home scheme, preventing even a small percentage of installations from needing remedial work saves multiples of the coordination fee, and protects the guarantee, the funding compliance and the residents.

Read the full case study

From our good-practice playbook

  • 40 mm minimum sill overhangs with drip details
  • Starter track at DPC, 150 mm above ground
  • L-shaped boards at openings, no edge under 150 mm
  • Mineral-wool slithers in all board gaps
  • 100 mm minimum mesh laps in the basecoat
  • Correct two-coat silicone finish application
Proven results

Decarbonisation pathways we've delivered

Six site decarbonisation surveys completed under the LASER Zero Carbon Fund programme for the London Borough of Hammersmith & Fulham (2024–2025), schools, theatres, sports pavilions and community buildings.

Primary school
75% CO₂e cut

Melcombe Primary School

Whole-site plan combining fabric-first measures with heat-pump conversion and solar PV, 97 tCO₂e and 538,700 kWh saved per year.

Fabric firstHeat pumpSolar PV
Community school
68% CO₂e cut

Normand Croft Community School

1,512 m² of internal wall insulation, glazing that cut glazed-surface heat loss by 28%, LED lighting, heat pump and district-heating assessment.

IWIGlazingDistrict heating
Community building
1.9-yr payback

22 Exhibition Close

A tightly-scoped, high-value intervention: air-to-air heat pump saving 12,000 kWh/yr, proof that decarbonisation doesn't always need major capital works.

Heat pump39% CO₂e cut
How we work

The PAS 2035 pathway, disciplined, standards-based, every time

For domestic retrofit this maps directly onto PAS 2035; for non-domestic sites we apply the same rigour through the survey-to-delivery methodology proven on the LASER ZCF programme.

1

Intended outcomes & risk assessment

Clear objectives, risk pathway and scope. Funding fit confirmed early.

2

Whole-building assessment

Condition, occupancy, ventilation and heritage constraints captured; metered data analysed.

3

Heat-loss modelling & options appraisal

Costed, ranked measures with kWh, £, tCO₂e, payback and £/tCO₂e.

4

Medium-term improvement plan

Correctly sequenced fabric-first roadmap: no lock-in, no unintended consequences.

5

Design coordination & specification

Details benchmarked against system-designer and INCA guidance.

6

Installation oversight

Site inspections, toolbox talks, mid-install checks, defect prevention.

7

Handover, monitoring & lodgement

TrustMark lodgement, monitoring plan, resident guidance and evaluation.

About

Engineer-led coordination, grounded in what we've seen built

Nanox Energy is led by Abd Alrahman, a Level 5 Retrofit Coordinator with a mechanical engineering background and energy & decarbonisation auditing expertise.

Every measure we recommend is grounded in what we have surveyed, calculated, specified and seen built, from investment-grade decarbonisation reports for a London borough to portfolio-scale defect analysis in one of the UK's most demanding exposure zones.

Level 5 Diploma in Retrofit Coordination and Risk Management, the qualification required to act as named Coordinator on funded schemes.
Energy Surveyor on local-authority decarbonisation programmes, co-author of investment-grade site reports under the LASER Zero Carbon Fund.
Portfolio-scale PAS 2035 quality review: 270 external wall insulation installations analysed against INCA best practice.
Whole-building expertise: traditional and heritage construction, low-carbon heating design, solar PV feasibility, fabric upgrade specification.
Funding landscape

We know what funders score, and how to win

Warm Homes: Social Housing Fund Whole-house plans, PAS 2035 compliance and fleet prioritisation for the SHDF successor.
ECO4 / GBIS Measure eligibility, scoring and installer compliance.
Public Sector Decarbonisation Scheme Heat-decarbonisation plans in the format Salix expects, as delivered across the LASER ZCF programme.
Local & devolved net-zero funds Borough climate funds, Welsh Government ORP-style programmes and community-building grants.

Planning a retrofit programme, a funding bid, or worried about compliance?

A typical first step is a free 30-minute scoping call, followed by a fixed-fee pilot survey or compliance review, so you can judge the quality of our work before committing to a programme.

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