Green Mark explained: the rating sits on the building
A lease says the building holds Green Mark certification, and the warm meeting room upstairs starts to read as a broken promise. Both things can be true at once. The rating was awarded to a project, and that room was never inside what got assessed.
By Team Snowflake | Updated 8 Aug 2026
What Green Mark is, and who awards it
Green Mark is Singapore's green building rating system. It is run by the Building and Construction Authority, which launched the scheme in January 2005. Its purpose is to evaluate a building's environmental impact and performance, and to return a rating for the result.
The scheme is voluntary. BCA publishes a listing of Green Mark buildings, and that listing is drawn from voluntary certification. Legislated projects sit outside it, and so do owners who opted out of public disclosure. A building absent from the list has therefore failed nothing, and reading absence as a verdict gets the logic backwards.
A rating and a code of practice do different work, and the two get named interchangeably. A code prescribes method, and the ACMV code of practice is the one covering cooling and ventilation on commercial premises. A rating scores a submitted project against criteria and returns a tier. Doing well on one settles nothing about the other.
The current scheme, Green Mark 2021, applies to new and existing buildings across commercial, industrial, institutional and residential types. Its criteria fall into six groups: energy efficiency, whole life carbon, resilience, intelligence, health and wellbeing, and maintainability. Nothing in that list grades a brand of equipment. The scoring looks at a development, and equipment appears only as part of how the development performs.
Green Mark is also a family, not a single certificate. BCA runs a separate scheme for data centres with IMDA, another for transit stations, another for districts, and another for interiors. So the words green mark certified, given alone, leave the reader without the one detail that decides what was examined. The scheme name is the detail.
What got assessed, and at which point
A certificate names a project and a date, and both matter. Green Mark 2021 carries a route for new work assessed around design and construction, and a separate In Operation route that measures a building after people have moved in. Those two answer different questions. One reports what was designed and built. The other reports how the building behaved once occupied.
That split explains a lot of the confusion an occupier runs into. A rating earned on the design route describes intent, specification and installed systems. It was settled before anybody occupied the space. A rating earned on the operating route describes measured performance across the whole building, averaged over everything inside it.
Certificates also expire. BCA's own listing records the rating, the certificate date and the expiry date for each entry. A rating awarded some years ago described the building as it stood then. Since then plant gets replaced, tenancies get subdivided, headcount rises, and a floor once fitted as open-plan office gets carved into meeting rooms.
Assessment runs at project level, so no part of it grades one tenancy. The criteria groups reach across a whole development. There is no line anywhere in them reporting the temperature in a particular room on a particular afternoon, and no mechanism by which one would appear.
What sits above a given tenancy is a separate question again. Whether the space is fed by an air handling unit or by fan coils decides where its outdoor air comes from, which the AHU vs FCU comparison works through. Where outdoor air gets conditioned before it arrives, a PAU does that job upstream. Neither fact is recoverable from a certificate.
Where does a Green Mark requirement come from?
Certification being voluntary does not mean nothing is compulsory. The legal floor under new buildings sits in a separate instrument. That instrument is the Building Control (Environmental Sustainability) Regulations, made under the Building Control Act. They set a minimum environmental sustainability standard. It covers new buildings, and older ones under major retrofit. The rule took effect in April 2008.
Read the shape of that obligation closely, because it is the part most often misdescribed. It asks for a standard to be met. It does not ask for a certificate to be obtained. A building can satisfy the regulation in full and never appear on any published list of rated projects, which is one reason BCA excludes legislated projects from its voluntary listing.
The duty falls on the design team. BCA states that the qualified person submitting the building plan, together with the other appropriate practitioners, is jointly responsible for ensuring the building works meet the minimum standard. A declaration and submission form go in with the building plan, and an as-built version goes in before the application for temporary occupation permit. A tenant appears nowhere in that chain.
Floor area decides whether the regulation bites at all. From 1 December 2021 the trigger is a gross floor area of 2,000 square metres or more, and extensions adding that much floor area count too. Between April 2008 and November 2021 the figure was 5,000 square metres. Smaller projects fall outside the requirement entirely.
Where a Green Mark rating itself is compulsory, a contract usually put it there. BCA requires buildings on Government Land Sales sites sold from 30 June 2022 to reach Green Mark Platinum Super Low Energy with the Maintainability Badge, and that condition travels in the tender documents handed to the successful developer. Jurong Lake District and Marina South carry further badge conditions on top. A developer bound this way is bound by the terms of a land sale.
| Where the requirement is written | Who it binds | What an occupier owes under it |
|---|---|---|
| Where the requirement is writtenBuilding Control (Environmental Sustainability) Regulations | Who it bindsThe qualified person and practitioners on the submission | What an occupier owes under itNothing. It closed before the lease existed |
| Where the requirement is writtenPart IIIB duties on a large existing building | Who it bindsThe building owner | What an occupier owes under itNothing directly, though the owner may ask for access |
| Where the requirement is writtenA Government Land Sales tender condition | Who it bindsThe developer who bought the site | What an occupier owes under itNothing. It was answered at completion |
| Where the requirement is writtenA lease clause or a fit-out manual | Who it bindsThe tenant who signed the lease | What an occupier owes under itWhatever the clause says, in full |
| Where the requirement is writtenGreen Mark for Interiors, once applied for | Who it bindsWhoever chose to apply | What an occupier owes under itOnly what that application commits to |
The duties that sit with the owner of an existing building
Existing buildings carry obligations of their own, and they land on the owner. Part IIIB of the Building Control Act reaches buildings with a gross floor area above 5,000 square metres that install or replace a cooling system. Industrial buildings, data centres, places of worship, transport facilities and residential buildings sit outside it, with serviced apartments treated as an exception.
Three duties follow for a building inside that scope. The minimum environmental sustainability standard has to be met on a major energy-use change. Energy efficiency audits of the building's cooling system have to be run on a regular cycle. Energy use and related building information has to be submitted, feeding an annual benchmark based on energy use intensity. Buildings that come out energy-intensive face a further improvement regime.
For a tenant, the practical value of knowing this is narrow and real. It means the cooling plant serving a large air-conditioned building is already measured on a cycle by somebody. Asking the managing agent when the last cooling system audit ran is a fair request with a real answer behind it. That request and a question about the building's rating go to the same person and return different documents.
Why is a unit still warm in a Green Mark building?
A rating describes environmental performance across a development, and comfort in one room is a different measurement taken at a different scale. A tenancy running warm is reporting something local. Local causes are the ones worth working through, and all of them are checkable.
Start with what the space is asking for. Heat load is set by the room itself, by how many people are in it, by glazing, and by whatever equipment runs inside. A fit-out changes all four at once. An office converted into a demonstration kitchen has moved its heat load without anybody touching a single unit, and equipment correct for the previous use is undersized for this one.
Airflow is the second place to look, and fit-out works are where it usually goes wrong. Grilles get boxed in behind new partitions. Ceiling voids get crowded with services added by successive tenants. Dampers get left wherever the last occupier set them. A lease, a floor plate drawing and a lobby certificate all leave that invisible.
Fresh air is a third and separate axis, and it explains complaints that cooling alone never fixes. A room can hold temperature and still feel stale, because moving air across a coil and bringing outdoor air in are different jobs. The measure that tracks the second one is air changes per hour, and it is set by how the space is used.
Then there is the equipment, where a fault reads the same in a rated building as anywhere else. Certification does not keep a coil clean, hold a thermistor in calibration, or stop a drain silting up. The plant serving a rated building ages on the same schedule as the plant next door.
The trap worth naming is treating the rating as an answer and stopping there. A tenant told the building is certified tends to conclude the discomfort must be theirs to absorb. Push back and ask three things: which equipment serves this space, who owns it, and when it was last measured. A certificate answers zero of the three. Whoever holds the plant records answers all three.
What to settle before the rating enters the conversation
Separate the building's paperwork from the equipment overhead, and most of the confusion drops out. One belongs to the owner or the managing agent. The other belongs to whoever signed for the tenancy and whoever maintains what was installed in it. Ratings, codes and leases answer to three different people.
Fit-out is the point where a rating genuinely reaches an occupier, and it arrives through the lease. A landlord can write a condition into the lease or into the fit-out manual, and a tenant is then bound by contract for the duration. BCA also runs Green Mark for Interiors, a scheme built for interior fit-out projects and covering premises such as commercial offices, restaurants, retail units, supermarkets and laboratories. It took effect on 1 November 2025 and consolidated five earlier occupant-facing schemes. Applying for it remains a choice somebody makes.
The design standard behind the cooling is a third instrument, and it travels by yet another route. SS 553 sets the terms a mechanical design has to answer, and it lands on a project through whoever endorsed that design. A rating scores the project that was handed in. A code fixes what that project had to meet. Confusing the two produces an argument nobody wins, because the answers sit in different offices.
Getting these questions answered before signing is worth more than getting them answered afterwards. At handover the leverage is real and the drawings are still open, and the checks that belong there are covered under office aircon fitout handover. Once the lease runs, the same questions cost goodwill to ask.
- Which Green Mark scheme and which edition the building's certificate names
- Whether the certificate covers the base building only, or reaches into tenanted space
- Whether the units serving your tenancy are landlord plant or tenant-owned equipment
- What the fit-out manual requires, and whether the lease repeats or extends it
- Who holds the commissioning readings for the equipment above your ceiling
- When the building's cooling system was last audited, and who commissioned that audit
Where the criteria stop being fixed
Criteria move between editions, and BCA publishes the current version of every scheme it runs. What a rating asked for under one edition is not what it asks for now, so a certificate is only readable alongside the scheme and edition it was awarded under. Scoring, tiers and cost belong to BCA's published pages, which are revised on their own schedule.
Efficiency ratings on individual equipment run on a completely separate track, and they are worth keeping apart from any of this. What a single aircon model is permitted to be sold at is fixed by MEPS, and what its label has to disclose is fixed by MELS. A building rating and an equipment rating share a vocabulary and measure different objects.
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