Energy & carbon
Commercial Energy Audits
Building-level energy audits with investment-grade financial appraisal — every measure carries capex, NPV, payback and carbon savings, so recommendations are decision-ready.
What it is
Detailed, building-level energy audits that identify cost-effective energy and carbon reduction measures across fabric, services and controls.
Every measure is presented with an investment-grade financial appraisal — capex, annual saving, simple payback, 15-year NPV and carbon impact — so recommendations are decision-ready rather than generic.
Audits are designed to be usable both as a technical work-list for facilities teams and as a board-grade business case for capital approval.
When you need it
- You want to reduce energy cost and carbon across a building or estate and need to know where to spend first.
- You need ESOS-grade audits that meet Lead Assessor expectations for evidence and rigour.
- You are building a business case for capital spend on energy measures and need defensible payback and NPV figures.
- You're planning major plant replacement (heating, cooling, lighting) and want a properly appraised options assessment.
- You operate a multi-site estate and need a consistent audit approach to compare and prioritise across assets.
Our approach
- 1
Consumption and tariff review
Analyse 12+ months of energy consumption and tariff data by meter and fuel to baseline performance and identify anomalies.
- 2
Site survey
On-site survey covering building fabric, HVAC, controls, lighting, small power and any process loads — including BMS interrogation where available.
- 3
Identification of measures
Identify a full slate of measures across fabric (insulation, glazing), services (heat pumps, LED, VSDs, solar PV) and controls (BMS, sub-metering, remote monitoring).
- 4
Investment-grade financial appraisal
Appraise each measure using HM Treasury Green Book methodology — 3.5% discount rate, HMT energy price escalation, 15-year horizon — to produce defensible NPV and payback.
- 5
Carbon savings quantification
Quantify carbon savings using current DEFRA GHG conversion factors, so reported tCO2e align with your wider SECR, GHG Protocol and investor reporting.
- 6
Prioritisation and reporting
Rank measures by payback, NPV and carbon impact and produce a report written for both technical teams and board-level decision-makers.
What you receive
Prioritised schedule of measures
A ranked schedule of energy and carbon reduction measures, ready to feed straight into a capital plan.
Capital cost and annual saving
Indicative capex, annual energy saving (kWh) and annual cost saving (£) for every measure.
Payback and 15-year NPV
Simple payback plus 15-year NPV under HM Treasury Green Book assumptions, so finance teams can compare measures on a like-for-like basis.
Carbon savings
Annual and lifetime carbon savings (tCO2e) using current DEFRA factors — usable in SECR, GHG Protocol and investor reporting.
Decision-ready report
A single report written for both technical teams and board-level decision-makers — no separate "exec summary" needed.
Why NZC Consultants
- Accredited ESOS Lead Assessor
- Sterling Accreditation registered
- Energy Institute member
- Independent — no software resale, no kit sales
Frequently asked questions
Speak to an NZC Consultants assessor
Tell us about your building or estate and we'll scope an audit package that fits — we'll respond within one working day.