Office Fit-Out Lighting, Controls and Sub-Metering in Singapore: What a Landlord Should Specify

A floor can be fitted out with efficient fittings, a new distribution board and a building management system, and still be unable to answer the simplest question an asset manager will ask about it five years later: how much of this floor’s electricity went on lighting? The reason is almost always decided during the fit-out, by people who were solving a different problem at the time.

The electrical installation in most office fit-outs is designed to serve the incoming tenant. That is a reasonable brief, and it is not the same brief as leaving behind an installation that can be measured. By the time anyone wants the measurement — a Green Mark assessment, a comparison between floors, an energy improvement notice — the lighting circuits have been altered, loads have been mixed across boards, and the meters that exist cannot separate lighting from supplementary cooling.

None of that is expensive to prevent and all of it is expensive to investigate. This article sets out what a landlord can reasonably specify at fit-out stage so the floor stays legible afterwards. It is written from the construction side: Rongda builds to what the electrical consultant specifies, and the coordination failures described here are the ones that show up on site. For the service itself, see our Green Mark and sustainable fit-out contracting.

Decide what the finished floor is supposed to be able to tell you

Before the electrical design is approved, somebody has to say which parts of the floor’s consumption need to stay separately identifiable. This gets skipped because it resembles a question that has already been answered. Has the tenancy got enough capacity? Yes. That answer says nothing about whether the installation can be read later.

The landlord and the electrical consultant set the measurement boundary together, then decide whether future reporting has to distinguish lighting, general power, supplementary cooling or anything else that matters in that building. What is appropriate depends on the infrastructure that already exists. A floor in a building with a mature metering strategy needs something different from a floor in a building that has never measured anything below the main intake.

It is worth being precise about the regulatory position here, because it is routinely overstated. BCA’s Mandatory Energy Improvement regime assesses existing buildings at building level, using Energy Use Intensity. Green Mark for Interiors is a separate certification route for eligible interior spaces, administered by the Singapore Green Building Council. Neither of them should be read as imposing one sub-metering specification on every office tenancy in Singapore, and we have found no provision that makes tenant-floor sub-metering a statutory duty. What the applicable assessment requires is for the appointed energy professional to determine.

Lighting power density is settled on a schedule, not on site

Lighting Power Density expresses installed lighting power against the area it serves. It lets the designer test an arrangement before anything is bought. It is emphatically not a consumption figure: what a floor actually uses depends on operating hours, occupancy and whether the controls survive contact with the occupants.

Under the Singapore Green Building Council’s Green Mark for Interiors scheme, the assessment compares the design’s LPD against the allowance in SS 530:2024. SGBC publishes the improvement each rating requires.

The practical consequence is about procurement discipline. The luminaire schedule should name the fitting, the rated input power, the driver, the mounting arrangement and the control compatibility. A tender line that asks for energy-efficient LED fittings preserves nothing. Substitution is where the design quietly dies: a contractor offers a visually identical fitting with a different driver, the light level is fine, and the calculated LPD or the control compatibility is no longer what was approved. Alternatives go back to the electrical consultant before purchase, and the revised documentation gets kept for the assessment and the handover file.

Control zones should follow the people, not the ceiling grid

The most common lighting-control failure in a commercial fit-out has nothing to do with the controls. It is that the circuits were arranged for the convenience of the installation while the partitions were arranged for the convenience of the occupier, and nobody reconciled the two.

The fix is unglamorous: set the zones from the functional layout, then make the drawings say which luminaires belong to which zone, how each zone is controlled and what it interacts with. Where a room needs individual control, the wiring has to allow that separation. A reflected ceiling plan that looks like separate rooms is not evidence that the circuits are separate.

On multi-tenanted floors there is a second requirement that is easy to forget at fit-out stage and expensive to add later: the next tenancy may be subdivided differently. Whether a control system can be reconfigured without opening ceilings depends on the original wiring, the spare controller capacity and whether anyone can physically reach the equipment. The controls consultant sets the architecture; the fit-out contractor coordinates the construction around it.

A sensor with no written sequence of operation will not survive its first year

Occupancy sensing stops lights running in empty rooms, when it is placed and programmed properly. A sensor behind a partition, or looking at a decorative ceiling feature instead of the room, does not detect what it was bought to detect. A time delay set too short produces a room that goes dark during a meeting, and an occupant who disables it.

Daylight response needs the same care and gets less of it. A perimeter office and an internal meeting room are different problems. Whether daylight sensing belongs in a given space, and how the artificial lighting should respond, is a design decision that has to account for glare, shading, task requirements and where the workstations actually end up — which is often not where the furniture layout said they would.

What makes the difference at handover is the sequence of operation: when lights come on, when they dim, when they switch off, how after-hours works, which manual overrides exist and what resets them. If the facilities team cannot work out which sensor serves which room, the system degrades one override at a time until it is doing nothing. Commissioning records should carry the approved settings and evidence that the installed system behaves the way the consultant specified.

Sub-metering: fewer meters that mean something

Sub-metering measures consumption below the main incoming supply. Its value is entirely determined by what each meter is actually measuring. Adding meters without first deciding what question they answer produces more readings and no more information, plus a maintenance obligation nobody costed.

Meter positions and the electrical arrangement have to be resolved before the distribution boards are ordered, because enclosure space, current-transformer arrangements, isolation and communication connections all have to fit inside equipment that is about to be manufactured. Retrofitting a meter into a board that was not designed to take one is a different job with a different price.

One detail carries more weight than it looks: the label. A meter label should describe the load it actually serves, not repeat the board number it sits in. If lighting and general power were combined downstream during construction, the records must not imply they are separately measured. Someone will rely on that label years after everyone involved in the fit-out has moved on.

A reading nobody can retrieve is not a measurement

A meter can be accurate and useless at the same time. In a large property, sending somebody round the electrical rooms to write down numbers does not survive as a routine, which means the data exists in principle and not in practice.

Decide how the readings will be collected before specifying the meters, not after. Local reading, scheduled export, an energy management platform, integration with the building management system — each implies different hardware. Where remote communication is required, the specification has to name the interface, the data points, the naming convention and who is responsible for integration. A communication-capable meter is not the same thing as a building whose software can collect and interpret its data.

The handover package should say where each reading comes from, what it represents and how to investigate a gap in the data. It should also give the facilities team somewhere to record meter replacements and circuit changes. Without that, a step in the numbers looks like a change in building performance when it is really a change in the measurement system — and that mistake can send an entire retrofit investigation in the wrong direction.

Draw the landlord and tenant boundary on the drawings, not in the lease alone

Lighting is only part of what an office consumes. Workstations, comms rooms, pantry appliances and supplementary cooling all contribute, and their relative weight depends on what the tenant actually does. A trading floor and a back-office tenancy of the same area are not comparable.

The distinction that matters operationally is which equipment the base building serves and which the tenant installed and controls. Central cooling may come from the landlord’s system while the tenant runs its own unit for a specialist room. How those are supplied, controlled and measured is for the electrical and mechanical consultants to establish — but it has to end up on the fit-out drawings and the equipment schedules, because that is what the next team will read.

A board schedule that says only general power can hide a significant supplementary cooling load. The reverse error is just as common: making a tenant responsible for equipment that stays under the landlord’s operational control. The aim is not a meter per appliance. It is that someone reviewing this floor later can see where the consumption sits without opening panels.

The partition layout can quietly undo the electrical design

Interior changes affect electrical systems even when the floor area does not move. A meeting-room partition shifts two metres and the control zone no longer matches the room. A full-height feature wall blocks a sensor. A revised ceiling design leaves a driver, controller or communication device behind a sealed surface.

These are coordination items, not finishing items, and they belong in shop drawing review. The architect, electrical consultant and controls specialist confirm the relationship between the partition layout, the reflected ceiling plan, the lighting circuits and equipment access. The fit-out contractor’s job is to raise the discrepancy before fabrication rather than discover it after the ceiling is closed, when resolving it means reopening finishes, modifying wiring and repeating tests. The practical trade-offs between partition systems are covered in our comparison of glass and drywall office partitions.

Tenant fit-out guidelines are what protect this five years later

A landlord can commission a well-documented installation and watch it come apart at the next fit-out. Circuits get combined, controls get bypassed, loads move between boards. If none of that is recorded, the measurement system degrades without anyone deciding to degrade it.

Fit-out guidelines should say what may be altered and what has to be submitted when it is: updated single-line diagrams, circuit schedules, lighting control layouts, equipment schedules and the relevant test records. The requirement should be proportionate to the work — demanding a full set for a single added socket guarantees that nobody complies with anything.

Access deserves a decision rather than a default. A meter inside a tenant-controlled room may be effectively unreachable for the landlord afterwards. Either the monitoring equipment sits somewhere the landlord can reach, or the access provision is agreed and written down. Where the work happens in an occupied building, the shutdown and access constraints are a programme problem in their own right; we set those out in our guide to A&A works permitted hours and access windows.

Commissioning has to prove what the floor does, not that the lights come on

Accepting a lighting installation because every fitting illuminates tests almost nothing. Commissioning should demonstrate that the control zones, sensors, schedules and overrides behave the way the approved design says they do, and that each meter corresponds to the load it claims.

Testing responsibilities are worth agreeing before completion rather than during it. Typically the electrical contractor handles installation testing, the controls specialist verifies programming and communication, the consultant sets the acceptance criteria and reviews the evidence, and the fit-out contractor coordinates access, ceiling completion and making good around all of it.

These are the documents an asset manager starts from when the building is later assessed or improved. Without them, the first phase of any retrofit study is paying somebody to rediscover the electrical installation. Where several floors are involved, this documentation belongs in the overall office renovation programme rather than being left to the end. The wider assessment context is covered in our article on Green Mark Version 7 and what changes for interiors.

What Rongda does here, and what it does not

Rongda Pacific Pte Ltd carries out commercial interior fit-out, A&A works, custom carpentry, metal fabrication and the associated builder’s works. Where a landlord or consultant has specified lighting, controls or metering requirements, we coordinate the interior construction around them with the appointed electrical and controls contractors: ceiling alterations, partition coordination, access provisions for equipment, supports, joinery modifications, making good and the interfaces between all of those. We provide shop drawings, inspection records and as-built information for our own scope.

Rongda is not a Green Mark consultant, a registered energy auditor or an electrical design certifier. The appointed professionals set the performance requirements and the assessment criteria; we build to them and supply the construction records needed for coordination and handover. If you are planning a floor and want the construction interfaces considered early, that is the conversation to have before the ceiling design is frozen — see our Green Mark fit-out contracting service or our wider commercial fit-out contracting scope.