EPC · asset rating
Modelled performance of the fabric and services; for commercial buildings a carbon-based Environmental Impact Rating.
What MEES tests; valid for MEES if lodged no more than 10 years before it is relied on.Software · building energy, cited
Building energy software: EPCs, DECs and MEES data
Building energy software holds a building’s meter, sub-meter and BMS data and the certificates built from it.
In England and Wales that data meets four legal duties at building level — MEES, DECs, EPCs and air-conditioning inspections — and feeds the company’s SECR and ESOS figures. This page sets them out and computes which apply to your building.
What it holds
What does building energy software hold?
It holds the building-level evidence that a company-level platform rarely keeps.
A carbon platform needs a building’s annual kWh; a building energy tool needs the lodgement date of its EPC, the nominated date of its DEC and the date of its last air-conditioning inspection.
The same meter history serves both, because a DEC is built from 12 months of measured use under regulation 15 of the Energy Performance of Buildings Regulations 2012.
The test of a tool is whether one reading can feed the certificate, the landlord’s evidence and the company report without being keyed three times.
- 1
Meters and sub-meters
kWh by building, floor or system; the measured basis of a DEC.
- 2
BMS data
Set points, run hours and alarms that explain why the meter moved.
- 3
Certificates
EPCs with lodgement dates, DECs, recommendation and inspection reports.
- 4
Improvements
Measures, costs and payback evidence for a let building.
- 5
Company reports
The building’s kWh in SECR and its place in the ESOS buildings purpose.
Your building
Which duties apply to this building?
Four duties attach to the building rather than the company, and each has its own trigger.
MEES follows the letting, DECs follow public occupation, air-conditioning inspections follow the plant, and Scotland runs a separate regime under SSI 2016/146.
The tool beside this takes the nation, floor area, letting, occupier and air-conditioning output, and lists the duties with their provisions.
It is a first sort: exemptions, listed buildings and part-building lets all change the answer.
Which building energy duties apply
| Duty | What it asks | Status |
|---|---|---|
| Minimum energy efficiency standard (MEES) | A let non-domestic property that needs an EPC must not be let below band E on a valid EPC (lodged no more than 10 years before it is relied on), unless a registered exemption applies. SI 2015/962 regs 22, 27 | In force |
| EPC B from 2031 (proposal) | Proposed for private rented buildings over 1,000 m², “where cost effective”, only after secondary legislation passes. Not law today. DESNZ interim response, 18 June 2026 | Proposed |
| Air-conditioning inspection | Accessible parts inspected by an energy assessor at intervals not exceeding five years; keep the latest report. SI 2012/3118 regs 18, 20 | In force |
A first sort, not legal advice: exemptions, part-building lets and listed buildings change the answer.
Nothing is stored or sent.
EPC or DEC
Is an EPC or a DEC the better measure of a building?
They answer different questions, and a tool should keep both.
An EPC says how the building should perform; MEES relies on it, and an EPC is “valid” for MEES only if it was lodged no more than 10 years before it is relied on, under reg 22(c).
A DEC says how the building did perform, from twelve months of metered use, with the ratings of the previous two years beside it, under reg 15.
The government has decided to keep the carbon-based Environmental Impact Rating as the headline of reformed non-domestic EPCs, according to its partial response on EPC reform, which has slipped to the second half of 2027.
One
building
building
DEC · operational rating
Measured energy over 12 months ending no earlier than three months before the nominated date.
Shows the last two years’ ratings beside this one.MEES
What does MEES ask of a let commercial building?
A landlord must not continue to let a non-domestic property below band E on a valid EPC, unless a registered exemption applies, under the 2015 Regulations.
The improvements a landlord must make are limited by the seven-year simple payback test in regulation 28, which compares seven years of bill savings with cost, excluding VAT, times an interest factor.
So the evidence a tool must keep is the EPC with its lodgement date, the candidate improvements with their costs and modelled savings, and any registered exemption with its expiry.
Read what changed in June 2026
DESNZ’s interim response dropped the proposed 2027 EPC C milestone and proposed EPC B from 2031 for private rented buildings over 1,000 m², “where cost effective”, only after secondary legislation passes.
Buildings below 1,000 m² are intended to stay at band E, and the payback test and exemptions remain.
The MEES-specific tooling is on MEES software, and the regime on MEES.
MEES, non-domesticExplore
MEES, non-domestic
Valid EPC
Lodged no more than 10 years before it is relied on, with none lodged since.
MEES, non-domestic
Seven-year payback
An improvement is required only if seven years of savings cover cost times an interest factor.
MEES, non-domestic
Penalties
Up to £50,000, or £150,000 for a breach of three months or more, by rateable value.
MEES, non-domestic
EPC B 2031
Proposed over 1,000 m², where cost effective, after secondary legislation.
Public buildings and plant
What do DECs and air-conditioning inspections require?
DEC trigger
Over 250 m²Occupied by a public authority, frequently visited by the publicDEC validity
12 monthsOver 1,000 m²; 10 years for smaller buildingsAir-con inspection
≤ 5 yearsSystems over 12 kW effective rated outputDEC for ESOS
RemovedNot a compliance route since 22 July 2026Every occupier of a building over 250 m² that a public authority occupies and the public frequently visits must display a valid DEC at all times and hold a valid recommendation report, under regulation 14.
A DEC lasts 12 months where the floor area is over 1,000 m², and 10 years for any other building.
Separately, the relevant person for an air-conditioning system over 12 kW must have its accessible parts inspected by an energy assessor at intervals not exceeding five years and keep the latest report, under regulation 18.
A building energy tool earns its keep here as a register of dates: a DEC that lapses every year is easy to miss across a large public estate.
DECs are no longer an ESOS compliance route, after SI 2026/701, though their data can still feed an ESOS report.
Into the company report
How does building data reach SECR and ESOS?
A building’s meters are where most of a company’s SECR energy figure comes from.
SECR asks for annual energy in kWh under ¶15(3A) of Schedule 7 for quoted companies and ¶20D(3) for unquoted companies, and building electricity is converted on the DESNZ factor for the year the energy was used.
ESOS treats buildings as one of four organisational purposes, each needing its own energy intensity ratio under reg 25C.
For property portfolios, SASB’s Real Estate metric IF-RE-130a.4 asks for the share of eligible floor area with an energy rating, and GRESB’s BC2 scores energy ratings on floor-area coverage.
Portfolio emissions are covered on real estate carbon accounting software.
From building to reportExplore
From building to report
SECR kWh
Building gas and electricity in the company’s annual energy figure.
From building to report
SECR emissions
Purchased electricity on the DESNZ factor for the activity year.
From building to report
ESOS buildings purpose
One of four organisational purposes, each with an intensity ratio.
Scotland and Northern Ireland
Do the same rules apply across the UK?
| Nation | Let commercial buildings | Source |
|---|---|---|
| England and Wales | MEES: band E minimum on a valid EPC; payback test; registered exemptions. | SI 2015/962 |
| Scotland | No EPC-band letting ban. Buildings over 1,000 m² on sale or lease need an action plan, then the improvements within 42 months or annual DECs. | SSI 2016/146 |
| Northern Ireland | No private rented minimum energy efficiency instrument was found; treat as unconfirmed. | Energy Act 2011 s.42 for the E&W extent |
A UK estate needs a tool that knows which nation a building sits in, because the trigger, the metric and the deadline all change at the border.
An order of work
Where should a property team start?
- 01 / Register01
- 02 / Certificates02
Load the certificates
EPC lodgement dates, DEC nominated dates, inspection reports. - 03 / Meters03
- 04 / Let stock04
Test the let stock
Band against E; improvements against the payback test; exemptions registered. - 05 / Report05
Ratings beyond the lawExplore
Ratings beyond the law
NABERS UK
Measured in-use office ratings, one to six stars; voluntary.
Ratings beyond the law
SASB IF-RE-130a.4
Share of eligible portfolio with an energy rating.
Ratings beyond the law
UK SRS S2
Industry-based guidance an entity may refer to and consider.
In short
What should a board take from this?
Every building carries its own duties, and the meter data behind them is the same data the company reports.
| What is true | What it means for a tool |
|---|---|
| MEES is band E today, in England and Wales only. | Track each let building’s band, EPC lodgement date and exemptions. |
| A DEC lasts 12 months over 1,000 m². | Hold nominated dates and renewals for every public building. |
| Air conditioning over 12 kW is inspected at least every five years. | Keep plant ratings and the latest report per system. |
| EPC B from 2031 is a proposal, not law. | Model it for buildings over 1,000 m² without treating it as a deadline. |
| Building kWh feeds SECR and ESOS. | One reading, used once, flows to every report. |
Next, see how measures are proved on energy efficiency software.
This site has tested no products
Nothing on this page is a rating, ranking or recommendation of any product.
Frequently asked
Building energy software, answered
What is building energy software?
Software that holds a building’s energy data — meters, sub-meters, the building management system and its certificates — and turns it into the ratings and reports the law and investors ask for.
In the UK that means EPCs, DECs, MEES evidence and air-conditioning inspection records, plus the building’s share of SECR and ESOS figures.
What is the difference between an EPC and a DEC?
An EPC is an asset rating: it models how the building should perform.
A DEC shows the operational rating, calculated from 12 months of actual energy use ending no earlier than three months before the nominated date, alongside the ratings shown in the previous two years (SI 2012/3118 reg 15).
Which buildings need a display energy certificate?
In England and Wales, buildings over 250 m² occupied by a public authority and frequently visited by the public.
The occupier must display a valid DEC at all times and hold a valid recommendation report.
A DEC lasts 12 months over 1,000 m² and 10 years otherwise (SI 2012/3118 reg 14).
A private office has no DEC duty.
Can a DEC still be used for ESOS?
Not as a compliance route.
SI 2026/701 removed DECs and Green Deal Assessments as alternative routes from 22 July 2026.
The data behind a DEC can still feed an ESOS report.
What is the MEES minimum for commercial property?
Band E, in England and Wales.
A let non-domestic property that needs an EPC must not be let below band E on a valid EPC unless a registered exemption applies.
Non-domestic penalties can reach £50,000, or £150,000 where the breach lasts three months or more, depending on rateable value.
Is EPC B by 2030 law for commercial buildings?
No. DESNZ’s interim response of 18 June 2026 proposes EPC B from 2031 for private rented buildings over 1,000 m², where cost effective, only after secondary legislation passes.
Buildings under 1,000 m² stay at band E, and the 2027 EPC C milestone was dropped.
How often must air conditioning be inspected?
In England and Wales, the accessible parts of a system with an effective rated output over 12 kW must be inspected by an energy assessor at intervals not exceeding five years, and the latest report kept (SI 2012/3118 regs 18 and 20).
Does MEES apply in Scotland?
No. MEES is England and Wales only.
Scotland has its own non-domestic regime under SSI 2016/146: buildings over 1,000 m² need an action plan on sale or lease, followed by the improvements within 42 months or annual DECs.
What rating does a commercial EPC give?
Its headline is the carbon-based Environmental Impact Rating.
The government has decided to keep it as the single headline metric on reformed non-domestic EPCs, expressly to keep non-domestic MEES working; EPC reform has slipped to the second half of 2027.
Do investors ask for building energy ratings?
Some frameworks do.
SASB’s Real Estate metric IF-RE-130a.4 asks for the share of eligible portfolio with an energy rating, and GRESB’s 2026 Real Estate Assessment scores energy ratings on floor-area coverage.
Under UK SRS S2, an entity may refer to and consider the industry-based guidance.
Is NABERS UK required?
No. NABERS UK is a voluntary rating of measured in-use office energy on a one to six star scale, launched in the UK on 26 November 2020, with CIBSE as scheme administrator since April 2024.
Has this site tested any building energy software?
No. This page is built from the building regulations, MEES, the ESOS and SECR provisions and the frameworks named, each cited to its source. It names, ranks and prices no product.
Sources
Primary sources
Every duty on this page traces to the provision listed here.
Checked against 18 sources fromlegislation.gov.ukDepartment for Energy Security and Net ZeroMHCLG and DESNZIFRS FoundationGRESBNABERS
- legislation.gov.ukEnergy Efficiency (Private Rented Property) (England and Wales) Regulations 2015, Part 3
Band E minimum; a valid EPC is one lodged no more than 10 years before it is relied on.
- legislation.gov.ukSI 2015/962, regulation 28
The seven-year simple payback test.
- legislation.gov.ukSI 2015/962, Part 3 Chapter 6
Non-domestic penalties up to £50,000 or £150,000.
- Department for Energy Security and Net ZeroNon-domestic MEES: interim response (18 June 2026)
EPC B from 2031 proposed over 1,000 m²; 2027 milestone dropped.
- MHCLG and DESNZReforms to the Energy Performance of Buildings regime
The carbon-based Environmental Impact Rating stays the non-domestic headline.
- legislation.gov.ukEnergy Performance of Buildings (England and Wales) Regulations 2012, regulation 14
Display energy certificates for public authority buildings over 250 m².
- legislation.gov.ukSI 2012/3118, regulation 15
A DEC shows the measured operational rating over 12 months.
- legislation.gov.ukSI 2012/3118, regulation 18
Air-conditioning inspections at intervals not exceeding five years.
- legislation.gov.ukAssessment of Energy Performance of Non-domestic Buildings (Scotland) Regulations 2016 (SSI 2016/146)
Action plans for buildings over 1,000 m² on sale or lease.
- legislation.gov.ukEnergy Act 2011, section 42
MEES powers reach property in England and Wales.
- legislation.gov.ukESOS (Amendment) Regulations 2026 (SI 2026/701)
DECs removed as an ESOS compliance route.
- legislation.gov.ukESOS Regulations 2014, reg 25C
An energy intensity ratio for buildings, among the four purposes.
- legislation.gov.ukSI 2008/410, Schedule 7
SECR: building energy in the company’s kWh and emissions.
- Department for Energy Security and Net Zero2026 GHG conversion factors methodology paper, Table 9
UK electricity factors by year.
- IFRS FoundationSASB Standards: Real Estate, IF-RE-130a.4
Share of portfolio floor area with an energy rating.
- GRESB2026 Real Estate Assessment, BC2 Energy ratings
Energy ratings score on floor-area coverage.
- NABERSNABERS UK
Measured in-use office energy ratings, one to six stars.
- Department for Business and TradeUK SRS S2 Climate-related Disclosures
Industry-based guidance an entity may refer to and consider.