Introduction and background to Singapore's Green Mark certification

The Building and Construction Authority (BCA) is the government agency overseeing safety, quality, inclusiveness, sustainability and productivity of the built environment sector in Singapore. Tasked by the government to champion the green building environment,¹ the BCA introduced the Green Mark certification scheme in 2005. This rating system promotes the adoption of green building designs and technologies that improve energy efficiency and reduce buildings' impact on the environment.²

Collaborating with the building industry and other relevant stakeholders, the BCA launched the first Green Building Masterplan in 2006 to increase industry efforts in environmental sustainability, with the focus on "greening" new buildings.³

In 2009, the BCA launched the second Green Building Masterplan, emphasizing the greening of existing buildings for which a major energy-use change has been proposed or that have undergone a major energy-use change. For the purposes of the Building Control Act 1989 and the Building Control (Environmental Sustainability Measures for Existing Buildings) Regulations 2013 ("2013 Regulations"), a "major energy-use change"⁴ in relation to an existing building means either of the following:

• The installation, substantial alteration or replacement of a prescribed cooling system (water-cooled chiller or air-cooled chiller⁵) of the building
• Any other change to the energy requirements of the building that may be prescribed

The latest Green Mark: 2021 certification,⁶ and the Code on Periodic Energy Audit of Building Cooling System also apply to existing buildings undergoing "major retrofitting works" involving the provision, extension or substantial alteration of the building envelope⁷ and building services in or in connection with an existing building⁸:

• Addition or replacement of chiller(s)
• Addition or replacement of 50% or more of all air-conditioning condenser units or, if adding or replacing air-conditioning condenser units, 50% or more of the currently installed capacity
• Additional gross floor area (GFA) of 5,000 square meters (m2) or more
• Projects subject to environmental sustainability regulations⁹

Developers and owners of new and existing buildings, districts, parks, infrastructure, and building interiors are assessed on the following five key criteria:¹⁰

• Energy efficiency
• Water efficiency
• Environmental protection
• Indoor environmental quality
• Other green and innovative features that contribute to better building performance

The process for applying for Green Mark certification involves several stages and an on-site inspection.

• At application: When paying a fee, applicants must provide detailed information on the design and construction of the project, including engineering calculations and material/equipment specifications.
• For verification: Applicants must supply other information, such as purchase/delivery orders.
• At assessment: The BCA assessors will visit the site for a detailed assessment.¹¹

When first introduced, the Green Mark assessment — based on scoring, performance levels and evidence collection — determined the Green Mark rating series:

All new builds and existing buildings with major retrofitting are now assessed under the refreshed standards and technical guides of the Green Mark: 2021 second edition. The BCA describes this latest certification framework¹² as follows:

• Simple: Many prerequisites of the first edition standards and technical guides have been removed, and the criteria have been restructured into two broad categories:
  • Energy efficiency (the only prerequisite)
  • Sustainability sections covering intelligence, health and well-being, whole-life carbon, maintainability and resilience

• Sustainable:
  • Criteria are mapped to the United Nations Sustainable Development Goals and contextualized for implementation within the built environment in Singapore and the urban tropics to push the energy efficiency envelope so as to mainstream Super Low Energy (SLE) buildings.
  • This recognizes future requirements from various sustainable finance taxonomies.

• Smart: This recognizes digitalization efforts to facilitate easy, seamless and secure certification processes.
• Owner-friendly: This recognizes building developers' and owners' needs for sustainable operations and environmental, social and governance reporting and demonstrating their leadership.
• Cost-effective: This increases sustainability with a value-driven approach, including environmental value, social value and economic value based on a life-cycle cost approach.
• User-friendly: This is a robust yet flexible framework that brings all buildings into the same ecosystem of Green Mark: 2021.

Green Mark: 2021 aims to raise standards in energy performance and place greater emphasis on other sustainability outcomes:

• Designing for maintainability
• Reducing embodied carbon across a building's life cycle
• Using smart technologies
• Enhancing a building's resilience to climate change
• Creating healthier environments for building users¹³

For previously Green Mark certified buildings not undergoing a retrofit, building owners can apply for a streamlined certification process "Green Mark: 2021 In Operation" to maintain the previous Green Mark rating or upgrade the rating based on the energy efficiency performance.

Under the Green Mark: 2021 assessment, which introduces a new Green Mark rating series, project teams have the option to pursue either or both of the following series:

• Green Mark Gold^PLUS or Platinum certification, which are comprehensive certifications that cover various aspects of sustainability
• Green Mark SLE certification, which is focused solely on energy efficiency

Each subsequent iteration of the Green Building Masterplan (the latest edition summarized below) increases and progresses certification standards. Compliance with the Green Mark: 2021 certification is voluntary. It recognizes performance that is above mandatory, regulated standards, and includes robust levels of energy efficiency, indoor air quality, greenery provision, active mobility considerations, materials and waste management, and water efficiency.

However, developers and owners of prescribed new buildings or existing buildings undertaking major energy use change or undergoing major retrofitting works that meet the building size requirements (or are projects on government land sale (GLS) sites) currently must comply with the minimum standards set out in the codes for new and existing buildings with a major energy use change or under retrofit, including achieving the minimum Green Mark score¹⁴, that are mandated by statute and regulations, as summarized below.

Owners of existing buildings which will be classified as "energy-intensive" under recent amendments to the Building Control Act 1989 should also be aware of the forthcoming statutory requirements and the Mandatory Energy Improvement (MEI) regime.

New buildings

For developers of new buildings, the Building Control (Environmental Sustainability) Regulations in 2008 ("2008 Regulations") require new builds of all building types¹⁵ with a GFA of 5,000 m2 or more¹⁶ to achieve a minimum Green Mark certification.¹⁷ The 2008 Regulations require these new builds¹⁸ to achieve a minimum score of points as set out in the Code for Environmental Sustainability of Buildings, which establishes environmentally friendly practices in planning, design and construction to mitigate the environmental impact of such structures. All new buildings must be 50% more energy efficient than the 2005 baseline.

Existing buildings undertaking major energy use change or undergoing major retrofitting works

The types of buildings initially subject to achieving a minimum Green Mark certification were large hotels, retail buildings, and office buildings with a minimum GFA of 15,000 m2.¹⁹ The 2013 Regulations were amended in 2017²⁰ with the latest prescribed buildings²¹ extended to include all single-use and mixed-use buildings with a GFA of 5,000 m2 ²² that install or replace their building cooling system.

Part 3B of the Building Control Act 1989 on environmental sustainability measures for existing buildings requires owners of existing buildings (except for types A and B) to do the following:

• Comply with the minimum Green Mark environmental sustainability standard
• Submit periodic energy efficiency audits of the building's cooling systems
• Submit information in respect of energy consumption and other related information as required by the Commissioner of Building Control (CBC)

The buildings exempt from the requirements of Part 3B of the Building Control Act 1989 are classified as either of the following:

• Type A buildings used as the following:
  • Data center²³
  • Religious building
  • Residential building (other than serviced apartments)
  • Utility building

• Type B buildings used as follows:
  • As an industrial building, an industrial retail building, a light industrial building or a special industrial building²⁴
  • As railway premises
  • To provide airport services and facilities²⁵
  • To provide port services and facilities²⁶

The 2013 Regulations also require all prescribed buildings to achieve a minimum score of points set out in the Code on Environmental Sustainability Measures for Existing Buildings, which establishes environmentally friendly practices in the operation and retrofitting of existing buildings. The building energy performance must be optimized to meet the minimum energy improvements of 40% over the 2005 baseline when retrofitted.

Existing buildings classified as "energy-intensive"

As of 2024, only existing buildings undertaking major energy use change or undergoing major retrofitting works are required to meet minimum energy performance requirements and meet prevailing sustainability standards after such upgrades.

Noting that, if such works are not carried out, there is no requirement for building owners to improve their building’s energy performance, the BCA has proposed amendments²⁷ to the Building Control Act 1989, to introduce the new MEI regime²⁸.

The BCA recognizes the need to accelerate energy efficiency improvements in existing buildings, which account for over 20% of Singapore’s carbon emissions, in order for Singapore to shift towards a low-carbon built environment and to achieve net-zero emissions by 2050.

This new MEI regime, expected to be implemented in the third quarter of 2025 ²⁹, will require owners of energy-intensive buildings to appoint a qualified professional mechanical engineer or energy auditor registered with the BCA to carry out an energy audit and develop an Energy Efficiency Improvement Plan (EEIP) to reduce the building’s energy use intensity³⁰ (EUI) by at least 10% from pre-audit levels.

The BCA uses EUI as the benchmarking metric to measure building energy efficiency. EUI is calculated by dividing a building's total annual electricity consumption (in kWh) by its GFA (in m²) and allows for the comparison of a building's energy performance against similar building types³¹.

When implemented, the amended Building Control Act 1989 will expand the regime in Part 3B relating to environmental sustainability measures for existing buildings³² in each of the building typology or sub-typology used as follows:

• Retail
• Hotel
• Office
• Hospital
• Polyclinic/Private Clinic
• Nursing Home
• Education
• Civic, Community and Cultural
• Sports and Recreation centres

The CBC will apply the MEI regime to energy-intensive buildings with GFA of 5,000 m2. The EUI thresholds will be set out in subsidiary legislation for each building sub-typology, in recognition of the fact that different sub-typologies will have different energy use profiles.

A building will be considered energy-intensive if it exceeds a predetermined EUI threshold over a period of three years. For a start, the predetermined EUI threshold will be pegged at the 75^th percentile of the EUI range. The buildings subject to the MEI regime are those that are consistently in the top 25% of their building sub-typology in terms of energy consumption over three years. The EUI threshold will remain fixed for a period of five years before the next review.³³

The MEI regime will be outcome-based and neither the amended Building Control Act 1989 nor the CBC will stipulate the types of improvement measures that building owners need to undertake. Building owners have the autonomy to decide the measures to implement that are most appropriate for their buildings, as long as the required reduction is achieved. Depending on the building’s existing condition and energy performance, these measures can range from simple and low-cost such as the replacement of faulty parts and sensors, or the insulation of hot water systems, to more extensive retrofitting works such as the replacement of the building’s chiller systems or other behavioral changes such as increasing the building's air conditioning temperature by 1 degree Celsius.

Green Building Masterplans

The BCA has continuously updated its Green Building Masterplan since its inception in 2006, and the latest Singapore Green Building Masterplan 2021 (updated in July 2022) sets out the built environment sustainability standards to achieve the BCA's low-carbon target of 80-80-80 in 2030. These are also adopted in the Green Mark: 2021 scoring.

1. Accelerating the greening of 80% of buildings by 2030, which includes the following steps:

• Annually publishing energy performance data in the Building Energy Benchmarking Report,³⁴ which does the following:
  • Informs building owners and facilities managers on how well their buildings have performed
  • Spurs them to initiate and implement improvements in building energy efficiency³⁵
  • Shapes the market through information transparency of buildings' energy performance

• Raising the mandatory environmental sustainability standards (including raising the minimum energy performance requirements for new buildings and existing buildings that undergo a major retrofit, and introducing mandatory sustainable construction practices to lower the carbon footprint of our buildings)
• Updating the Green Mark: 2021 scheme, aligned with the United Nations' Sustainability Development Goals, to raise energy performance standards and place greater emphasis on other important sustainability outcomes such as designing for maintainability, reducing embodied carbon across a building's life cycle, and creating healthier environments for building users

2. Requiring 80% of new developments by GFA to be SLE³⁶ buildings from 2030 by mandating the following:

• New public sector buildings attain Green Mark certification, including Green Mark Platinum for new buildings with an air-conditioned area exceeding 5,000 m2
• Green Mark Platinum SLE standards or equivalent for all new and existing buildings (upon a major retrofit)
• Enhanced sustainability standards to further drive energy efficiency and carbon reduction for projects developed on land sold under the GLS from June 2022

3. Increasing energy efficiency for best-in-class green buildings to an 80% improvement by 2030 by codeveloping alternative cooling technologies, data-driven smart building solutions and next-generation building ventilation with building owners and developers and through industry partnerships

[1] See About the BCA.

[2] See About the BCA Green Mark Scheme.

[3] See Green Building Masterplans.

[4] Section 22FA of the Building Control Act 1989.

[5] Regulation 4 of the 2013 Regulations.

[6] The BCA Green Mark: 2021 Certification Standard (Second Edition).

[7] “building envelope” is defined under the Building Control Regulations 2003 to mean the elements of a building which enclose air-conditioned spaces through which thermal energy may be transferred from the exterior

[8] See Annex B: Factsheet on Mandatory Energy Improvement (MEI) Regime

[9] Including the environmental sustainability measures for existing buildings set out in Part 3B of the Building Control Act 1989 and Building Control (Environmental Sustainability) Regulations 2008 for new buildings where applicable

[10] See About the BCA Green Mark Scheme.

[11] See FIDIC Rating & Certification Tool: BCA Green Mark.

[12] The BCA Green Mark: 2021 Certification Standard (Second Edition).

[13] The BCA Green Mark: 2021 Certification Standard (Second Edition).

[14] Section 22FA of the amended Building Control Act 1989: when the amendments come into force in 2025, the definition of “environmental sustainability score” or “ES score” replaces the definition of “Green Mark score” as the numerical score to assess the environmental sustainability of buildings. The definition of “major energy‑use change” will be amended to “major energy use change” because the latter term is more commonly used in the built environment sector (even though there is no change in the meaning)

[15] All building types include industrial, institutional and commercial buildings (office, hotel, retail and mixed development), stations, port facilities, residential and residential landed buildings, and simple structures such as farms and bridges; see FAQ on Building Control (Environmental Sustainability) Regulations 2008.

[16] Regulation 3(1). Exempting projects involving a GFA of less than 5,000 m2 from the need to comply with the 2008 Regulations is based on the BCA's assessment of standards stipulated by the Energy Conservation Act 2012, which addresses inefficient building systems at the source and supply end, particularly for smaller projects; see BCA Circular: Amendments to The Building Control (Environmental Sustainability) Regulations 2008 and adoption of the Code For Environmental Sustainability of Buildings (edition 4.0) and Code on Environmental Sustainability Measures for Existing Buildings (edition 3.0); 1 September 2021.

[17] Regulation 6(1)(b).

[18] Projects with a planning permission submission date on or after 1 December 2021 must adopt the fourth edition of the Code for Environmental Sustainability of Buildings.

[19] Regulation 3(1), superseded.

[20] Building Control (Environmental Sustainability Measures for Existing Buildings) (Amendment) Regulations 2016.

[21] Section 22FA of the amended Building Control Act 1989: when the amendments come into force in 2025, the definition of “prescribed building” will be replaced with definitions of “Type 1 building” and “Type 2 building” to allow the Minister to prescribe different types of buildings for the existing regime and the new Mandatory Energy Improvement regime

[22] Regulation 3(1) of the 2013 Regulations.

[23] Data centers must nonetheless comply with SS 564-1:2020 Sustainable data centres - Part 1: Energy and environmental management systems and SS 564-2:2020 Sustainable data centres - Part 2: Guidance for energy and environmental management systems, developed and updated by the Infocomm Media Development Authority (IMDA) from time to time to reduce data centers' energy consumption and operating costs and enhance their competitiveness. The 2013 revisions are modeled after the ISO 50001 standard on energy management and specifically tailored to meet the needs of data centers in Singapore; see IMDA: Green Data Centre Standard.

[24] See the NEA: Industrial Sector Mandatory Energy Management Practices for Existing Industrial Facilities and note that, from 22 April 2013, a corporation:

• Has operational control over a business activity that has attained the energy use threshold of 54 terajoules of energy used per calendar year in at least two out of the three preceding calendar years
• Carries out the business activity at a single site and is attributable to one of the following sectors:
  • Manufacturing and manufacturing-related services
  • Supply of electricity, gas, steam, compressed air and chilled water for air-conditioning
  • Water supply and sewage and waste management
• Will be a registrable corporation under the Energy Conservation Act 2012 and subject to the stipulated energy management practices under the Energy Conservation Act 2012 and the Energy Conservation (Energy Management Practices) Regulations 2013.

[25] Changi Airport Group (Singapore) Pte Ltd, whose assets and operations under CAG's business control include four passenger terminal buildings, Changi Airfreight Complex and the aircraft operating areas of Changi Airport, maintains ISO 14001:2015 certification for Energy and Emissions Management; see Changi Airport Group Forging A Sustainable Changi Sustainability Report 2021 – 2022.

[26] The Maritime Singapore Green Initiative, introduced by the Maritime and Port Authority of Singapore in 2019 and extended to 31 December 2024, comprises four voluntary programs for ships, ports and green energy to promote decarbonization of shipping.

[27] The Building Control (Amendment) Bill, first introduced in Parliament on 6 August 2024, passed on 10 September 2024

[28] See the BCA media release: Changes to the Building Control Act to enhance Energy Efficiency measures in Existing Buildings for a Sustainable Future 10 September 2024

[29] See the BCA media release: Changes to the Building Control Act to enhance Energy Efficiency measures in Existing Buildings for a Sustainable Future 10 September 2024

[30]  EUI refers to the annual energy consumption of a building per unit of GFA (expressed in kilowatt hour per square metre per year)

[31] See BCA: Building Energy Benchmarking

[32] Explanatory statement to the Building Control (Amendment) Bill

[33] Opening Speech by Senior Minister of State Sim Ann on the second Reading of Building Control (Amendment) Bill; 10 September 2024

[34] See the BCA Building Energy Benchmarking Report (Statistics and Figures) 2021.

[35] From 2023, the BCA will also provide individual energy performance data for healthcare facilities, sports and recreation centers, and institutional buildings, and identify them by name. Buildings will be ranked by energy performance among other buildings of similar typology. The next edition of the report will be published on the BCA's website; see Budget 2023: speech by the senior minister of state for national development and communications & information; 2 March 2023.

[36] See the BCA's Super Low Energy program.