The second stage of Hong Kong's Building Energy Efficiency (Amendment) Ordinance 2025 took effect on 20 September 2026. The audited building list grew from 2 types to 11, the audit interval halved to five years, and Form EE-D now publishes two lighting numbers as a percentage of lighting area coverage: lamp type mix and automatic lighting demand control. This article sets out what to measure before the audit window opens.
The second stage of the Buildings Energy Efficiency (Amendment) Ordinance 2025 took effect on 20 September 2026. Five things changed for building owners on the same day. One of them makes lighting data public.
The second stage of the Buildings Energy Efficiency (Amendment) Ordinance 2025 came into force on 20 September 2026. Five things changed for building owners at once. Four of them reach the lighting installation directly, and one of them makes lighting data public.
The operational consequence is narrow and specific. The audit does not ask whether the lighting looks good. It asks three measurable questions: what lamp types cover the lit floor area, what share of that area has automatic lighting demand control, and what is the total lighting power in kW. Two of the three answers are area-weighted, not count-weighted. Before the cycle starts, check whether the existing luminaire schedule maps each zone to floor area and records fitting wattage including control gear. Where it does not, verify or rebuild that mapping before the audit.
What this changes for a lighting specification. To keep reporting cheap on a five-year cycle, an office lighting package should hand over three things: one luminaire register keyed to floor area, one wattage basis that includes drivers and control gear, one control narrative that says which zones carry automatic lighting demand control and how much power the control sheds. Whether a package meets the Ordinance is decided by the audit and the Registered Energy Assessor, not by the supplier. Without those three artefacts, the owner pays the reconstruction cost at every audit.
This section carries the numbers, the clause references and the worked examples. It also states the boundary of what a lighting supplier can and cannot decide on a building owner's behalf.
The Amendment Ordinance was published in the Gazette on 20 June 2025 and implemented in two stages. The second stage took effect on 20 September 2026. The official description of the second stage sets out five changes: bring data centres fully into the regulatory scope of the building energy efficiency standards; require more types of buildings to conduct energy audits regularly; shorten the energy audit interval; disclose technical information in the energy audit reports; and widen the qualification accepted for registration as a Registered Energy Assessor (REA).
Only one of those five mentions lighting hardware, and it is not the one that matters most in practice. The BEC 2024 tightening happened earlier and mostly without publicity: the Code of Practice for Energy Efficiency of Building Services Installation (Building Energy Code, BEC) 2024 and the Code of Practice for Building Energy Audit (Energy Audit Code, EAC) 2024 were fully implemented on 23 August 2025, and EMSD records that the revision "uplifted the energy efficiency standards by more than 20% as compared with the 2015 edition". A building owner who spent 2025 watching the Ordinance calendar and not the Code revisions would have missed the LPD and lighting control changes entirely.
The practical reading is this. The Ordinance change decides whether and when an audit happens. The Code change decides what numbers the audit will treat as compliant. Both apply to the same site, and the second one is the one that a lighting supplier can act on.
Before 20 September 2026, only two types of building required an energy audit: a commercial building, and the portion of a composite building that is for commercial use. The second stage added nine more:
Two consequences follow immediately for facility teams that were never audited before.
First, the duty follows the building category, and two exemption routes exist. The Energy Audit Code applies to the categories prescribed in Schedule 4 of the Ordinance and repeats that the duty applies "save for exclusion or exemption under the Ordinance" (clause 4.2). EMSD's 2026 pamphlet describes the first route: the amendment exempts the energy audit requirement for "buildings with gross floor area not exceeding 7,000 square meters", except a building occupied principally as a data centre and a data-centre portion of an industrial building. The second route is an application: under section 25 an owner may ask the Director for exemption from the section 22(4) duty where the circuit protective devices solely governing the central building services installation do not exceed 400A, 3-phase (EAC 2024 Addendum No. 1/2025, clause 4.4). The 400A figure is therefore an exemption threshold, not a scope test. A school campus, a clinic and a data hall each need checking against Schedule 4, the 7,000 m² gross-floor-area exemption, and any section 25 application that fits the building's own supply arrangement.
Second, data centres get no soft landing. EMSD's summary of the second stage lists "把數據中心全面納入建築物能源效益標準的規管範圍": data centres are brought fully within the scope of the building energy efficiency standards. A small data hall inside an industrial building is therefore a space to check rather than to assume out of scope. The lighting inside a data hall is a hard case: it runs continuously, it is rarely switched at the luminaire, and its control strategy is usually tied to the IT load rather than to occupancy.
There is one Code relief worth knowing here. Clause 5.5.5 of BEC 2024 provides that "For any space, other than carpark, with lighting installation designed for 24 hours a day and 7 days a week operation, the requirements in clause 5.5.1 should not be applicable." A data hall designed for continuous operation therefore escapes the 250 m² control-point cap. It does not escape the disclosure. Form EE-D section 3.3.2 still asks what share of the lighting area carries automatic lighting demand control, and a data hall with no automatic control of any kind reports a true zero. Zero is a legitimate answer; an unexplained zero in a 24/7 space is the kind of entry that invites the next question.
For a lighting team, this means the interesting 2026 conversations are no longer only in Grade A offices. They are in libraries, indoor games halls, clinics, station concourses and data halls — spaces with long operating hours and poor as-built lighting records.
The interval shortened from "no longer than 10 years" to 5 years. That is a cadence change, not a one-off filing. An owner who audits in 2027 should expect the next audit to fall due inside five years, and should plan the lighting works schedule around that rhythm rather than around a building refurbishment cycle.
The owner does not need to guess the deadline. Form EE-5, the Energy Audit Form, carries a field titled "Commencement of next energy audit by". The REA who issues the form sets that date, and the Ordinance requires the REA to send a copy of the form and the audit report to the Director "within 30 days after issuing an Energy Audit Form" under section 22(5). The date therefore arrives in the owner's file as a by-product of the previous audit.
Two duties sit on the owner rather than on the REA. Form EE-5 note 10 states that "The owner of building should properly maintain and keep the original copy of the Energy Audit Form and all relevant supporting documents (including energy audit report)". The form also notes that the data in it may be disclosed to the public on application. So the record the owner keeps is not a private working file; it is the raw material of a public disclosure that can be re-checked against the next audit.
Practical consequence: the five-year clock turns a one-off audit into a repeating data obligation. Every artefact that the REA needs must survive five years of fit-out churn, tenancy changes and lamp replacements. A luminaire schedule issued at handover is not that artefact unless it is maintained.
This is the part of the second stage that most owners have not read carefully. The disclosure instrument is the Data Disclosure Form, Form EE-D, launched with BEEO Technical Circular No. 5/2025 on 19 December 2025. Its own wording describes the content as technical information of the central building services installations of the building, extracted from the energy audit report.
EMSD's own leaflet on the disclosure states the statutory list in plain terms: the Data Disclosure Form publishes the energy efficiency coefficient, the year of service, the control system and the energy saving potential of the major building services installations, and all buildings that have completed energy audits must submit the Data Disclosure Form to the EMSD. The leaflet also restates the display duty that predates the amendment: the owner exhibits the energy audit form at the main entrance of the building "to acknowledge that the building had carried out an energy audit".
Applied to lighting, the four disclosed fields map onto four numbers that a lighting schedule rarely carries in one place: the efficacy the audit derives from the installation, the year the installation was commissioned, the control description, and the saving the audit projects for that installation. A specification sheet cannot supply any of them on its own. They depend on what is installed, and on when.
Form EE-D is organised by installation. Air-conditioning is section 3.2. Lighting is section 3.3, and it has exactly two lines:
| Form EE-D field | What is recorded | Unit |
|---|---|---|
| 3.3.1 Use of Interior Luminaire | LED lamp, T5 fluorescent lamp, T8 fluorescent lamp, Compact fluorescent lamp, Other lamp type | % of lighting area coverage |
| 3.3.2 Energy Saving Control | Automatic lighting demand control | % of lighting area coverage |
That is the whole lighting disclosure. Two percentages. No luminaire count, no wattage, no brand, no model number.
Read that as a specification requirement and it is deceptively demanding. The disclosure does not describe the lighting installation; it describes the floor area served by each lamp type. A building with 300 luminaires, of which 260 are LED, cannot file "86.7% LED" unless the 260 LED luminaires actually cover 86.7% of the lit area. In a real mixed installation those two figures diverge, because lamp types are not distributed evenly across zones: back-of-house corridors in a 2015 office are usually the last area to be relamped, and they are also the area with the largest share of ceiling area per luminaire.
The second line carries the same trap. "Automatic lighting demand control" here is an area coverage figure, not a count of sensors. A floor with 40 presence detectors that cover the open plan but leave the meeting-room core on manual switching cannot claim the whole floor.
Note the wording boundary: the disclosure asks about the control's area coverage, while BEC 2024 clause 5.6.1.1 imposes a performance duty — the control "should be able to shut off or reduce the general lighting power by at least 50% automatically of the lighting zone being controlled". The two are related but not interchangeable. A scheme that dims a zone to 60% of full power satisfies neither reading: it reduces power by 40%, and it leaves the area technically "under control" while failing the Code's reduction test. Sensors that dim rather than switch must be checked against the 50% figure zone by zone.
Form EE-D is a summary extracted from the audit report. The audit report template, the Energy Audit Report for EAC 2024, asks section 4.2 for more:
| Audit report field | Content | Unit |
|---|---|---|
| 4.2.1 Use of interior luminaire | LED, T5, T8, T12, CFL, tungsten, discharge, other | approximate coverage, % |
| 4.2.2 Lighting control system | Computerized lighting control system, automatic time scheduling control, automatic demand control (e.g. sensor), other | approximate coverage in terms of lighting area, % |
| 4.2.3 Lighting power wattage | Total lighting power (based on luminaire wattage) | kW |
| 4.2.4 Supplementary information | Observations left by the REA | text |
Compare the two lists and the information architecture becomes obvious. The audit report splits control into four categories; the public form compresses them into one line, "Automatic lighting demand control". A building that runs automatic time scheduling but no occupancy sensing would report a healthy control percentage to the REA and zero on the public line. That gap is worth understanding before the site visit, not after.
The audit report also asks for total lighting power in kW based on luminaire wattage. This is the number that becomes LPD once divided by floor area, and it is the number that decides how a lighting upgrade is judged in the audit's energy management opportunity analysis.
There is a detail here that catches owners who read only the Code. The report-content duty in the Energy Audit Code is lighter than the template that carries it out. Clause 7.6.2(c)(ii) asks for "general descriptions, types and control systems of lighting installation" — no quantities, no wattage, no area coverage. The Energy Audit Report template asks for all three. Both documents are in play: the Code sets the statutory floor, and the template sets what the REA will actually hand over and what Form EE-D will be extracted from. Owners should plan to the template.
The practical test is simple. Before the REA's site visit, the property team should be able to answer four questions without leaving the room: how many luminaires of each lamp type serve each zone; what floor area each zone covers; what circuit wattage each fitting draws at full output including its driver; and which zones carry automatic control that sheds at least half of the general lighting power. If any of the four answers requires a site walk, the survey is starting late.
The Energy Audit Code defines lighting power density (LPD) operationally, and the definition is strict: the total power consumed by the lighting installation when all luminaires are energised at full output, including the consumption of the associated control gears, divided by the internal floor area of the space concerned.
Three consequences follow, and each one has bitten a real project.
Control gear is inside the number. A downlight specified as "20 W" and driven by a driver measured at 22 W at the terminals is a 22 W luminaire for LPD purposes. Multiplied across 300 fittings on a 1,500 m² floor, the difference between 20 W and 22 W is 600 W, or 0.4 W/m² — enough to move a marginal design across the allowance.
Full output is the basis. Dimming capability does not reduce the LPD calculation. An installation designed for 70% average output still reports at full output.
Floor area is the internal floor area of the space. Not the ceiling area, not the net usable area after furniture. This is why the "percentage of lighting area coverage" figures in §D.4 and §D.5 have to be built on the same area basis the LPD calculation uses. If the register maps luminaires to net lettable area while the LPD uses internal floor area, the two documents disagree, and the disagreement surfaces in the audit.
The allowance itself tightened in BEC 2024. For office space with internal floor area above 200 m² the maximum LPD moved from 7.8 W/m² to 7.2 W/m². Smaller office spaces moved too: at or below 15 m² from 9.5 to 9.0 W/m², and above 15 m² up to 200 m² from 8.9 to 8.5 W/m². Corridors moved from 7.0 to 6.0 W/m², car parks from 4.0 to 3.0 W/m², staircases from 6.0 to 5.6 W/m², and retail from 13.4 to 11.1 W/m². The direction is uniform: every space type in the summary tightened.
Take a 1,200 m² office floor that was partly relamped in three campaigns. The luminaire register lists 100 fittings: 80 LED, 15 T8, 5 compact fluorescent. A count-based reading gives an LED share of 80.0%.
Now map the same fittings to floor area. The 80 LED fittings sit in the open plan and serve 900 m². The 15 T8 fittings sit over 100 m² of back-of-house corridor. The 5 compact fluorescent fittings sit in a 200 m² canteen area with high ceilings and wide spacing.
| Lamp type | Fittings | Share by count | Area served (m²) | Share by area |
|---|---|---|---|---|
| LED | 80 | 80.0% | 900 | 75.0% |
| T8 | 15 | 15.0% | 100 | 8.3% |
| CFL | 5 | 5.0% | 200 | 16.7% |
| Total | 100 | 100% | 1,200 | 100% |
The same installation reports two different LED shares depending on the unit of account. Form EE-D asks for the second column. The count-based figure overstates the LED share by five percentage points, and it understates the compact fluorescent share by more than a factor of three.
This is the whole difficulty of the 2026 disclosure, compressed into one table. The data is not expensive to collect once. It is expensive to reconstruct after the fact, because the mapping requires either a reflected ceiling plan with area attribution, or a site walk with a laser measure and a zone schedule. Check the operations file for either document before assuming the mapping is already there.
BEC 2024 also changed the switch granularity, and the change is larger than most design teams expect.
Clause 5.5.1 caps the area served by a single lighting control point in any space that is not classified as an office at 250 m², down from 500 m², "unless the total electrical power consumed by the complete fixed lighting installations in the space does not exceed 70W". For office space the minimum number of control points comes from Table 5.5, which scales with area: 15 m² per point up to 10 points, 30 m² per point from 10 to 20 points, and 50 m² per point above 20 points.
Run the table on a 1,500 m² floor of the same building, with 300 luminaires rated 22 W each including driver. The applicable band is the top one, where 50 × (N − 12) < A ≤ 50 × (N − 11). For A = 1,500 m², the minimum is N = 41 control points, or roughly one per 36.6 m² of office area.
Clause 5.5.2 gives relief for efficient lighting: "In an office space with actual lighting power density value lower than the corresponding value in Table 5.4, fewer no. of control points can be provided, the percentage reduction of which should not be more than the ratio given by the difference between allowable LPD and actual LPD to the allowable LPD."
An installation at 4.4 W/m² against the 7.2 W/m² allowance has a difference of 2.8 W/m², which is 38.9% of the allowance. Applying that ratio to 41 control points gives a reduction of 15.9 points, so the minimum falls to about 25 points.
| Quantity | Value | Basis |
|---|---|---|
| Office floor area | 1,500 m² | assumed |
| Full-load lighting power | 6,600 W | 300 luminaires × 22 W including driver |
| Actual LPD | 4.4 W/m² | 6,600 ÷ 1,500 |
| Allowance, office above 200 m² | 7.2 W/m² | BEC 2024 Table 5.4 |
| Control points at allowance | 41 | Table 5.5 |
| LPD margin | 38.9% | (7.2 − 4.4) ÷ 7.2 |
| Control points after clause 5.5.2 relief | about 25 | 41 × (1 − 0.389) |
The same arithmetic cuts the other way, which is the part design teams miss. Moving from 4.4 W/m² to 4.8 W/m² raises the LPD, shrinks the margin from 38.9% to 33.3%, and lifts the minimum from about 25 points to about 27 points. Relief is a function of the margin, so it decays continuously: the closer a design sits to the allowance, the more control points it must provide. A retrofit at 7.0 W/m² leaves a 2.8% margin and therefore almost no relief at all. Treat the margin as a budget line, not as a rounding difference.
Automatic lighting control also tightened. Clause 5.6.1.1 requires automatic control in the spaces listed in Table 5.4 unless the complete fixed lighting installation in the space does not exceed 150 W, and the control must "shut off or reduce the general lighting power by at least 50% automatically of the lighting zone being controlled". Clause 5.6.1.3(a) caps the area served by one automatic lighting control zone at 250 m², down from 2,000 m², and clause 5.6.1.4 caps the area served by a manual override at 250 m², down from 500 m². Sports arenas moved from "No" to "Yes" in the Table 5.4 automatic control column. A single automatic control zone covering 2,000 m² of open plan — a common 2016 design — now needs at least eight zones at the 250 m² limit.
An energy audit under the EAC is not a compliance checklist. It produces an energy management opportunity (EMO) analysis, and the section on lighting generates EMOs from the same 4.2 data. Two properties of that analysis matter to a lighting supplier.
The EMO list is technical, not commercial. Lighting measures are generated from the installation description: lamp types, control systems, total power. An installation whose controls cover 58% of the lighting area generates different EMOs than one described as "manual switching throughout", even if the two installations consume the same energy.
The cost-benefit test has fixed inputs. The EAC requires the analysis of each EMO to consider the cost of implementation, the cost savings, the payback period, the service life of the proposed measure, and the degradation of savings over that life. Those inputs are auditable. A supplier claim about "up to 80% savings" that cannot be tied to a service life and a degradation assumption does not survive the analysis. This is the practical reason to quote measured wattage and a stated life, not a headline percentage.
The disclosure duty then closes the loop. The energy utilisation index in the Energy Audit Form is available for public inspection, and after the second stage the lighting mix behind that index is disclosed on Form EE-D. The next audit compares against the previous one. An owner who discloses a 75% LED mix in 2027 and a 75% LED mix in 2032 has to explain five years of no progress, whether or not the law demands an explanation.
The deliverable that survives the five-year cycle is a luminaire register with area attribution. The sequence below is written for a building whose next audit is due inside twelve months. It is a delivery plan, and every step produces a file.
| Month | Step | Output artefact | Owner |
|---|---|---|---|
| 0 | Confirm scope: building type, internal floor area, prior audit date, next audit date from Form EE-5 | Scope note | Property owner |
| 1 | Collect as-built lighting drawings, luminaire schedules, fit-out records, tenancy changes | Document set index | Property manager |
| 1–2 | Site walk: zone by zone, record lamp type, fitting count, circuit wattage including driver, and area served | Zone survey sheets | Lighting supplier plus property manager |
| 2 | Reconcile survey against drawings; flag deviations and unrecorded fit-outs | Deviation list | Lighting supplier |
| 3 | Build the register: one row per zone, with area, lamp type, fitting count, measured circuit wattage | Luminaire register v1 | Lighting supplier |
| 4 | Calculate LPD per space against BEC 2024 Table 5.4; identify spaces outside the allowance | LPD statement | Lighting supplier |
| 4 | Map control systems: which zones carry automatic demand control, what the control reduces power to, and the area covered | Control coverage map | Lighting supplier plus controls contractor |
| 5 | Confirm with the REA: area basis, measurement basis, treatment of partial-zone coverage | Written confirmation | REA and owner |
| 6–9 | Execute the lighting works that the audit will recommend | Commissioning records | Contractor |
| 10 | Restate the register post-works; recalculate LPD and control coverage | Luminaire register v2 | Lighting supplier |
| 11 | Hand the register, meter readings and commissioning records to the REA | Audit data pack | Owner to REA |
| 12 | File: keep Form EE-5, the audit report, the register, and the evidence of the register's maintenance | Five-year file | Owner |
Three details in that table carry most of the risk.
Month 5 is the step that gets skipped. The area basis must be agreed with the REA in writing before the survey is frozen, because the REA signs the audit report. An owner who builds a register on net lettable area and then meets an REA working on internal floor area has to redo the survey, and the redo lands inside the audit window.
Month 6–9 must not create a new discrepancy. A relamping campaign that changes lamp types in half a zone produces a register that no longer matches the installation. Either relamp by zone and restate the register, or state the mixed-zone share honestly. Mixed zones are the normal case in occupied buildings; they are also the reason a register needs a revision history.
Month 12 is a file, not a memory. Form EE-5 note 10 puts the maintenance duty on the owner: the original form and all supporting documents, including the audit report, are the owner's to keep. The register belongs in that file, because the next audit will not rebuild it.
One more artefact belongs in the file, and it is the one most owners forget: the wattage evidence. A register that states 22 W per fitting is a claim. A register backed by a driver datasheet, a measured input power at the circuit, or a commissioning record is evidence. When the next audit arrives five years later and the lighting contractor has changed twice, the evidence is what survives.
Four boundaries, stated plainly, because a compliance article that overstates its authority is worse than no article.
SUMLINK is a lighting supplier, not a Registered Energy Assessor and not a consultant of record. The audit, the audit report, the LPD determination that goes into it, and Form EE-D are the REA's professional outputs. This article describes the regulatory framework and the lighting data that the framework consumes. It does not substitute for the REA's judgement on any specific building.
Compliance is determined building by building. The building's category under Schedule 4, its gross floor area against the 7,000 m² exemption, the supply rating behind any section 25 application, its classification, and the treatment of a data hall inside a mixed-use building are all facts about a specific building. Two buildings on the same street can sit on opposite sides of the duty.
The 2025 stage-one provisions are out of scope here. This article covers the second-stage changes and the lighting-relevant Code changes. It does not analyse the REA registration qualification changes or the stage-one amendments.
The transitional treatment of buildings whose last audit predates 20 September 2026 is not settled in the public sources reviewed for this article. The interval is now 5 years, and Form EE-5 records the next audit date, but the sources captured here do not state how a building audited in, say, 2023 is scheduled. Owners in that position should read the date on their own Form EE-5 and confirm it with their REA. This is recorded as an open gap in §K rather than smoothed over.
Seven questions that come up before an audit window opens.
Does my building need an energy audit from 20 September 2026?
It depends on the building's category under Schedule 4 of the Ordinance and on the exemptions that apply to it. The 11 audited building categories are listed in §D.2. Buildings with gross floor area not exceeding 7,000 m² are exempt from the audit requirement, except data-centre buildings and data-centre portions of industrial buildings. Separately, an owner may apply under section 25 for exemption from the section 22(4) duty where the relevant circuit protective devices do not exceed 400A, 3-phase. Confirm the position for a specific building with the Ordinance, the Energy Audit Code, and a Registered Energy Assessor.
How often is the audit now required?
The statutory interval shortened from a maximum of 10 years to a maximum of 5 years on 20 September 2026. The next audit date is recorded on Form EE-5 under "Commencement of next energy audit by".
What exactly is published about my lighting?
Form EE-D section 3.3 publishes two percentages: the share of lighting area covered by each lamp type (LED, T5, T8, compact fluorescent, other), and the share of lighting area covered by automatic lighting demand control. Form EE-5 already makes the energy utilisation index available for public inspection.
Is "percentage of lighting area coverage" the same as the percentage of fittings?
No. The unit is floor area served, not fitting count. A building with 80% LED fittings can report a 75% LED area coverage, as the worked example in §D.7 shows.
Does dimming count as automatic lighting demand control?
It can, but the control must be able to shut off or reduce the general lighting power by at least 50% of the lighting zone being controlled, per BEC 2024 clause 5.6.1.1. A scheme that only trims output by 40% fails that test, however modern the sensors are.
Can an efficient lighting design reduce the number of required control points?
Yes, within limits. Clause 5.5.2 allows the control point count to drop by no more than the LPD margin expressed as a ratio of the allowance. At 4.4 W/m² against a 7.2 W/m² allowance, the margin is 38.9%, which takes a 41-point requirement to about 25 points.
Who signs the audit and the disclosure form?
The Registered Energy Assessor. The REA must, within 30 days after issuing the Energy Audit Form, send the form and the audit report to the Director under section 22(5). The owner keeps the originals and the supporting documents.
Deploy This Strategy — start with the luminaire register, not with the luminaire order. The Office lighting programme sets the scope, the area basis and the wattage basis in one pass and can help prepare a floor-area-based register; confirm the required Form EE-D fields with the Registered Energy Assessor before relying on it for filing: https://www.sumlink.hk/lighting-programs