The operating system for ESOS Phase 4
One platform to run ESOS Phase 4 from start to finish: energy data, site audits, Lead Assessor sign-off, MESOS notification, and the action plan and progress updates that follow. Built for the consultancies and Lead Assessors who deliver ESOS, and for the organisations that have to comply.
Live demo — open the steps marked Try › to edit the assessment, define AoSECs, allocate energy and record sign-off.
ESOS · Phase 4
Harbourgate Group — Phase 4 ESOS
1 Jan 2026 – 31 Dec 2026
Assessment Stage Report
Site Audit Reports
Complete (1)
Awaiting audit (2)
Site audits open in the full platform.
Assessment Stage Report
§1 Overview
Project identity and reference period. The reference period must cover a continuous 12 months that includes the ESOS qualification date for this phase.
Project
Phase 4 · Qualification 31 Dec 2026 · Deadline 5 Dec 2027
Reference period
31 Dec 2026
Phase 4 qualification date
5 Dec 2027
Notification deadline, via MESOS
95%+
Of energy use audited
7
Phase 4 documents, one workspace
For consultancies and partners
Run the whole platform under your own brand
Climatise is fully white-label. Your logo, your colours, client-safe read-only views. The assessor workflow, the generated reports and the evidence pack all carry your identity, not ours.
Delivered by Climatise, presented as yours.
The platform
Purpose-built software for ESOS Phase 4
Climatise replaces the per-client spreadsheet with a structured workspace. Energy data, audits, opportunities and sign-offs sit in one place, and every figure traces back to its source.
The demo above is the real interface. Open the interactive steps to edit the assessment, define AoSECs, allocate energy and record sign-off, just as an assessor would.
Data inheritance
Fill the assessment once. The audit inherits it.
The figures from the Assessment Stage Report carry straight into each Site Audit Report. Enter a number once and it stays consistent across the whole engagement.
- ✓Assessment data flows into every site audit automatically
- ✓One set of figures, consistent across every document
- ✓Assessors review and refine instead of re-typing
Energy data in any format
Upload bills, half-hourly data and fleet records. Climatise maps them to sites, fuels and your reference period.
AoSEC and 95% coverage
Define your areas of significant energy consumption and confirm you have audited at least 95% of total energy use.
Costed opportunities
Every recommendation carries its annual kWh and cost saving, and links back to the audit that identified it.
Extrapolation across the estate
Project audited findings across comparable sites to support the Audit Summary Report.
Role-based sign-off
Lead Assessors edit, clients review, directors confirm. Every approval is recorded against the engagement.
Evidence pack and MESOS exports
Compliance documents grouped the way the Environment Agency expects, exported as a single ZIP.
One workspace, the full lifecycle
Every Phase 4 document, in sequence
ESOS is a sequence of dependent documents. Historically each one lived in a separate spreadsheet. Climatise runs them as a single engagement, so the status, deadline and sign-off of every report stays visible.
- 1
Assessment Stage Report (ASR)
Qualification, responsible undertaking, group structure, and the route to compliance.
- 2
Site Audit Reports (SARs)
One per audited site and area of significant energy consumption, with opportunities and evidence.
- 3
Audit Summary Report (ASuR)
Consolidates findings, extrapolates across the estate, and carries the sign-off block.
- 4
Notification of Compliance (NOC)
Submitted to the Environment Agency through MESOS by 5 December 2027.
- 5
Action Plan
The energy-saving measures you commit to, signed off by a board-level director.
- 6
Progress Update 1
First annual report on delivery against the action plan, in the year after compliance.
- 7
Progress Update 2
Second annual progress report. DESNZ confirms the exact Phase 4 dates in updated guidance.
climatise
Assessment Stage Report
ESOS
Energy Savings Opportunity Scheme · Phase 4
Harbourgate Group Holdings Ltd
1 January 2026 – 31 December 2026
Total energy
11.6 GWh
Sites
7
AoSECs
5
Sign-off
2/2
Prepared for
Harbourgate Group Holdings Ltd
Issued by
Climatise Ltd
Group assessment
Assessment Stage Report
climatise
Site Audit Report
ESOS
Energy Savings Opportunity Scheme · Phase 4
Phase 4 compliance deadline · 5 December 2027Seacliff Leisure — Brighton Seafront Hotel
24 Marine Parade, Brighton, BN2 1TN
1 Jan 2026 – 31 Dec 2026
Total energy
1.50 GWh
Intensity
313 kWh/m²
Opportunities
5
Saving
128,000 kWh/yr
Prepared for
Seacliff Leisure — Brighton Seafront Hotel
Issued by
Climatise
BS EN 16247 site audit
Site Audit Report
Generated from the workspace as branded PDFs. Shown with fictional demo data.
Audit-ready by default
The reports you submit, and the evidence behind them
Phase 4 ends in finished reports: the group Assessment Stage Report and a Site Audit Report for each audited site. Climatise generates both from your workspace, then collects every supporting document into one evidence pack, grouped the way the Environment Agency expects and exported as a single file.
Governance and sign-off
ASR, SARs and ASuR with Lead Assessor and director written confirmations.
Energy consumption records
Reference-period data by site, fuel and AoSEC, with estimation and exclusion notes.
Group structure
Participating undertakings and the MESOS organisation-structure export.
Compliance-route evidence
Energy audit or ISO 50001 routes, with supporting certificates.
MESOS submissions
Notification of compliance and the action plan, captured against the engagement.
Site audit evidence
Extrapolation workings and site photo evidence, gathered as audits complete.
One dataset, three frameworks
Collect the energy data once. Report it three ways.
ESOS Phase 4, SECR and UK SRS draw on 70 to 80% of the same energy data. Climatise keeps one defensible dataset and produces each framework from it.
Streamlined Energy and Carbon Reporting
Annual energy and carbon disclosure in the Directors’ Report.
ESOSEnergy Savings Opportunity Scheme
Four-yearly energy audit, action plan and progress updates.
UK SRSUK Sustainability Reporting Standards
Emerging ISSB-aligned disclosure framework for UK companies.
More than a compliance workspace
ESOS is one workflow in a year-round carbon platform
Phase 4 doesn’t end at notification. The same audited energy dataset powers continuous tracking and a reduction module, so the savings you identify actually get delivered and measured every month, not every four years.
Take the full platform tour →Analytics and dashboards
Track energy, cost and carbon across the estate all year, using the same audited figures that sit behind your ESOS reports.
See reporting →
Reduction module
Model scenarios, set targets and track delivery against the cost-effective opportunities your audits surface.
See reductions →
Built for both sides of an ESOS engagement
Consultancies deliver Phase 4 for their clients. In-scope organisations have to comply. Both run on the same platform.
Energy consultancies and Lead Assessors
Deliver Phase 4 across every client
Run each engagement as a structured workflow instead of a bespoke spreadsheet. Climatise is the platform behind your assessors.
- ✓Serve more clients without adding headcount. One workflow per engagement.
- ✓White-label presentation: your brand, with client-safe read-only views.
- ✓Roles built in: Lead Assessor edits, client and director sign off.
- ✓An assessor-ready evidence pack, assembled for the Environment Agency.
In-scope organisations
Get Phase 4 done, and keep the value
If you employ 250 or more people, or exceed £44m turnover and £38m balance sheet, you are in scope. Climatise takes you from energy data to a signed-off assessment.
- ✓Confirm whether you qualify on the 31 December 2026 qualification date.
- ✓Audit at least 95% of energy use across buildings, transport and processes.
- ✓Lead Assessor sign-off and MESOS notification by 5 December 2027.
- ✓Action plan and annual progress updates tracked in one place.
Who qualifies for Phase 4?
Status is assessed on the 31 December 2026 qualification date. Either the employee threshold or both financial thresholds put you in scope.
250 or more employees
Any UK undertaking employing 250 or more people on the qualification date.
£44m+ turnover and £38m+ balance sheet
A smaller headcount, but exceeding both financial thresholds.
Corporate groups
If the highest UK parent qualifies, the whole UK group is in scope.
What Phase 4 requires
The core deliverables every participant must complete to be compliant.
An energy audit covering at least 95% of total energy consumption (your AoSEC)
12 months of energy data that includes the 31 December 2026 qualification date
Identification of cost-effective energy saving opportunities
Sign-off by an approved ESOS Lead Assessor
Notification of compliance through MESOS by 5 December 2027
An action plan with director sign-off, followed by two annual progress updates
ESOS Phase 4: frequently asked questions
The Phase 4 qualification date is 31 December 2026 and the notification of compliance deadline is 5 December 2027. The assessment must be signed off by an approved ESOS Lead Assessor and submitted via the MESOS reporting system by that date. An action plan and two annual progress updates follow notification; DESNZ is expected to confirm the exact Phase 4 progress-update dates in updated guidance.
Large UK undertakings qualify: any organisation with 250+ employees, or with annual turnover exceeding £44m AND a balance sheet exceeding £38m, measured on the 31 December 2026 qualification date. If the highest UK parent company qualifies, all UK group companies are in scope.
An ESOS Lead Assessor is a member of an approved professional register who reviews and signs off your ESOS assessment. Their sign-off, alongside a board-level director confirmation, is required before you notify compliance to the Environment Agency via MESOS.
From Phase 3 onwards, ESOS participants must submit an action plan setting out the energy-saving measures they intend to implement, signed off by a board-level director and submitted via MESOS. It is followed by two annual progress updates reporting actual delivery, so ESOS is now an ongoing cycle rather than a one-off audit.
The evidence pack is the set of documents the Environment Agency expects you to keep: the reports and sign-offs, the energy data used in calculations, group structure, compliance-route evidence, and MESOS submissions. Climatise assembles this automatically as each document is finalised, so it can be downloaded as a single ZIP on request.
Yes. Climatise is designed for partner-led delivery. Energy consultancies and Lead Assessors run engagements under their own brand, give clients safe read-only access and sign-off, and reuse one workflow across many clients without growing headcount in step with demand.
ESOS Phase 4, SECR and the emerging UK SRS draw on roughly 70 to 80% of the same underlying energy data. Climatise keeps one defensible dataset and produces each framework’s output from it, so collecting the data once serves all three.
See ESOS Phase 4 on screen
Book a demo and we will take you through a live Phase 4 engagement, from energy data to the assessor-ready evidence pack.
Book a demo