Green Mark Explained: The Rating Sits on the Building

Green Mark is Singapore's green building rating system, run by the Building and Construction Authority, which launched it in January 2005. It evaluates a building's environmental impact and performance, returning a rating for the result.

The scheme is voluntary. BCA's listing of Green Mark buildings draws on voluntary certification; legislated projects and owners who opted out of disclosure sit outside it. A building absent from the list has failed nothing, since absence is not a verdict.

A rating and a code of practice do different work, often named interchangeably. A code prescribes method, and the ACMV code of practice covers 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.

Green Mark 2021, the current scheme, applies to new and existing buildings across commercial, industrial, institutional and residential types. Its six criteria groups are energy efficiency, whole life carbon, resilience, intelligence, health and wellbeing, and maintainability. Nothing in that list grades a brand of equipment; scoring looks at a development, and equipment appears only as part of how it performs.

Green Mark is also a family, not a single certificate. BCA runs separate schemes for data centres with IMDA, transit stations, districts, and interiors. So the words green mark certified, alone, leave the reader without the detail that decides what was examined: the scheme name.

A certificate names a project and a date, and both matter. Green Mark 2021 carries a design and construction route for new work, plus an In Operation route that measures a building after people move in. Those answer different questions: one reports what was designed and built, the other how the building behaved once occupied.

That split explains much of the confusion an occupier meets. A rating on the design route describes intent, specification and installed systems, settled before anybody moved in. One on the operating route describes measured performance across the building, averaged over everything inside it.

Certificates also expire, and BCA's listing records the rating, certificate date and expiry date for each entry. A rating awarded years ago described the building as it stood then. Since then plant gets replaced, tenancies get subdivided, 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 span a whole development, and none reports the temperature in a particular room on a particular afternoon.

What sits above a given tenancy is a separate question. Whether the space is fed by an air handling unit or by fan coils decides where its outdoor air comes from, as the AHU vs FCU comparison works through. A PAU conditions that air upstream. Neither fact is recoverable from a certificate.

Certification is voluntary, but that does not mean nothing is compulsory. The legal floor sits in a separate law. It is the Building Control (Environmental Sustainability) Regulations, under the Building Control Act. Those rules set a minimum standard of environmental sustainability for new buildings and older ones under major retrofit. That standard has been effective since April 2008.

Read the shape of that obligation closely; it is the part most often misdescribed. It asks for a standard to be met, not a certificate obtained. A building can satisfy the regulation in full and never appear on any list of rated projects, which is one reason BCA excludes legislated projects from its listing.

The duty falls on the design team. BCA states that the qualified person submitting the building plan, with other appropriate practitioners, is jointly responsible for ensuring the works meet the minimum standard. A declaration and submission form go in with the plan, and an as-built version before the temporary occupation permit application. A tenant appears nowhere in that chain.

Floor area decides whether the regulation bites. From 1 December 2021 the trigger is a gross floor area of 2,000 square metres or more, and extensions adding that much count; between April 2008 and November 2021 the figure was 5,000. Smaller projects fall outside it.

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. The Maintainability Badge comes with that. That condition is carried in the tender documents to the developer. Jurong Lake District and Marina South add further badge conditions, so that developer is bound by a land sale.

A rating describes environmental performance across a development. Comfort in one room is a different measurement at a different scale. A tenancy running warm reports something local. Local causes are worth checking.

Start with what the space is asking for. Heat load is set by the room, by how many people are in it, by glazing, and by equipment inside it. A fit-out changes all four at once: an office converted into a demonstration kitchen has moved its heat load untouched, 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, voids get crowded with services added by successive tenants, and 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 axis. 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 is air changes per hour, 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 calibrated, or stop a drain silting up, and rated plant ages on the same schedule as the plant next door.

The trap is treating the rating as an answer and stopping there. A tenant told the building is certified tends to conclude the discomfort is theirs to absorb. Push back and ask which equipment serves this space, who owns it, and when it was last measured. A certificate answers none; the plant records answer all three.

Separate the building's paperwork from the equipment overhead, and most of the confusion drops out. One belongs to the owner or managing agent; the other to whoever signed for the tenancy and maintains what was installed. Ratings, codes and leases answer to three different people.

Fit-out is where a rating genuinely reaches an occupier, arriving through the lease. A landlord can write a condition into the lease or fit-out manual, and a tenant is then bound for the duration. BCA also runs Green Mark for Interiors, 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 remains a choice.

The design standard behind the cooling is a third instrument, travelling by another route. SS 553 sets the terms a mechanical design has to answer, landing on a project through whoever endorsed that design. A rating scores the project 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 afterwards. At handover the leverage is real and the drawings are still open, with the checks covered under office aircon fitout handover. Once the lease runs, the same questions cost goodwill.

• •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