Singapore: Green Mark Building Rating System

Green Mark Singapore

This guidance supports the Green Mark Singapore calculation scheme, for which the 'Whole Life Carbon Assessment, GLA / RICS, Green Mark' calculation tool is used.

Whole Life carbon (WLC) assessment guidance is consistent with BS EN 15978 and BS EN 15804 and to be read in conjunction with RICS Professional Statement (PS): Whole Life Carbon assessment for the built environment, with adaptation to the local context.

WLC assessment adopts the framework for appraising the environmental impacts of the built environment provided by BS EN 15978: 2011: (Sustainability of construction works — Assessment of environmental performance of buildings — Calculation method). It sets out the principles and calculation method for whole life assessment of the environmental impacts from built projects based on life-cycle assessment. The RICS PS serves as a guide to the practical implementation of the BS EN 15978 principles, which sets out technical details and calculation requirements, with adaptation to the local context in this document.

What is included in the scope?

Applicable to all new buildings (Non-Residential and Residential) and Existing Buildings with Addition and Alteration (A&A) works involving additional gross floor area (GFA) with new construction, and the addition of floors with independent substructures.

The assessment should cover the development’s carbon emissions over its lifetime, accounting for:

• Embodied carbon emissions It reports A1-A3, A4 and A5 phase emissions
• Operational carbon emissions It reports B1, B2, B3, B4-5, B6a/B6b and B7 emissions. (B6 regulated and unregulated)
• Any future potential carbon emissions ‘benefits’, post ‘end of life’, including benefits from reuse and recycling of building structure and materials. It reports C1, C2, C3, and C4 (C1 with a scenario) and D phase emissions.

Follow these steps to complete an assessment for Green Mark Singapore

Create a project and select the right calculation tool

Create a building project and select the Green mark tool as the chosen calculation tool.

Create your first design and set up the LCA Parameters

1. Default Service Life

• As Specified by Green Mark

2. Default transportation modes and distance

• Transport carbon emissions can be calculated using the BCA Carbon Calculator or One Click LCA

3. Material Manufacturing Localization Target

• Singapore Electricity Profile - IEA 2019 (or latest available)

Allowable carbon conversion factors

• Carbon dioxide equivalence (CO2e) emissions from electricity use, grid emission factor (Scope 2 emissions) can be assumed as 0.4085 kg CO2/kWh. (refer to EMA’s website on energy transformation for more information)
• Diesel CO2 emission factor can be assumed as 3186.3 kg CO2/tonne or 741.1 kg CO2/GJ (refer to NEA website on Greenhouse Gas Emission Measurement and Reporting Guide for more information)

5. End-of-life Scenario

• Market scenarios (This provides the required C1-C4 breakdown) For the purpose of the WLC assessment, this EoL stage is assumed to occur at the end of the reference study period (RSP). EoL stage is considered complete within the WLC assessment scope when the site is levelled to the ground and is ready for further use.

6. End-of-life energy recovery (module D)

• To calculate figures for module D, the figures should be reported as potential savings under module D, reported in kgCO2e/m2

Check the mandatory scope

Reference Study Period (RSP) 

WLC assessment is carried out based on the building life cycle within the reference study period (RSP). The default value of the reference study period shall be the required service life of the building.

Residential Building -> 50 years

Non-Residential Building -> 50 years

Fill in the building area

For WLC assessment, floor areas shall be taken from the BIM model, BoQ or cost plan, or architectural plans. The unit of measurement for floor area should be Gross Floor Area (GFA) to represent the entirety of the built asset.

Spatial Boundaries

The assessment should cover all building components and works relating to the proposed building and its intended use, including its foundations, and external works within the site. The site boundary shall be clearly demarcated in the building plan.

Floor area measurement

For WLC assessment, floor areas shall be taken from BIM model, BoQ or cost plan, or architectural plans. The unit of measurement for floor area should be Gross Floor Area (GFA) to represent the entirety of the built asset.

Quantity of measurement

For WLC assessment, material/ product quantities shall be taken from materials delivery orders, BIM model, BoQ/ Cost plan or estimation from architectural plans.

Units of measurement

WLC assessment results shall be reported in the following units: kg CO2 equivalent (kgCO2e), or multiples thereof appropriate, e.g. tCO2e.

Minimum Scope Requirement of WLC Assessment

Building Elements to be included

• Substructure
• Superstructure (main, external and internal)

Life-Cycle Stages to be included

• Product Stage (A1-A3)
• Construction Stage (A4-A5)
• Maintenance Stage (B2) - Facade
• Replacement Stage (B4) - ACMV
• Operational Energy Use (B6)

Full Scope Requirements of WLC Assessment

A complete WLC assessment should include, in addition to the minimum scope of WLC assessment, the remaining life cycle stages (including D to be reported separately) and cover all items listed in the project’s bill of quantities (BoQ), or design information identified in drawings, specifications, etc.

Carbon Data Sources

The following are acceptable sources of carbon data for materials and products, in order of preference:

• Type III environmental declarations (EPDs and equivalent) and datasets in accordance with EN 15804
• Type III environmental declarations (EPDs and equivalent) and datasets in accordance with ISO 21930
• Type III environmental declarations (EPDs and equivalent) and datasets in accordance with ISO 14067
• EPDs and datasets in accordance with ISO 14025, ISO 14040 and 14044
• Type III environmental declarations (EPDs and equivalent) and datasets in accordance with PAS 2050

Carbon data for modules [A1–A3], [B1], [B2], [B3], [C1],[C3], [C4] and [D] should be retrieved from the allowable carbon data sources specified and used in line with the project-specific scenarios developed at building level.

Carbon figures for the remaining life stages [A4], [A5], [B4– B7], [C2] should be calculated on a project-specific basis, considering the project location, likely procurement routes, anticipated operation and maintenance schedules and EoL scenarios. Where EPD data is used for these modules, the carbon values should be adjusted accordingly to fit the project-specific scenarios.

Steps for comparing the results with the benchmark.

1. Create a copy of the design and remove anything that is not glass, concrete and steel and then compare these results with the Green mark benchmarks.
2. This could also be done by classifying the relevant materials as "In scope" so we get the results automatically generated in the classifications graph.

Embodied carbon reference values of different building typologies

The embodied carbon reference values of different building typologies based on life cycle modules [A1] to [A4] for superstructure only in are adopted as baselines in the computation of embodied carbon reduction for Concrete, Glass and Steel for the development.

Input required material data

Modules A1-A5: Product Stage

Fill in your project information in One Click LCA by entering the design either manually or by import your data (see different import options here; guidance for data import can be found here). If you need help finding the right datasets for your building materials, check our guidance pages here and here.

Modules A1-A3: Product Stage

• Product stage accounts for carbon emissions arising from the cradle to gate processes; raw material supply, transport and manufacturing.
• Carbon emissions of materials from the product stage [A1–A3] can be calculated by assigning suitable emission factors derived from acceptable data sources, such as EPDs provided by the manufacturer to the given elemental material quantities .

Modules A4-A5: Construction Process Stage

• Modules [A4] and [A5] respectively capture the emissions associated with the transportation of the materials and components from the factory gate to the project site and their assembly into a building.
• [A4] Transport emissions must include all stages of the journey of the products following their departure from the final manufacturing plant to the project site, taking into account any interim stops at storage depots and/or distribution centres.
• [A5] The construction – installation process emissions arising from any on- or off-site construction-related activities must be included. This includes any energy consumption for site accommodation, plant use and the impacts associated with any waste generated through the construction process, its treatment and disposal.

Modules B1-B7: Use Stage

The Use Stage emissions include operational energy and water use and any embodied carbon impacts associated with maintenance, repair, replacement and refurbishment of building components over its entire life cycle, from practical completion to the end of its service life. (Note: [B7] is excluded from WLC assessment) Reasonable Use scenarios should be developed for maintenance, repair, replacement, refurbishment, and operation of the building based on project-specific information and consultation with the project team.

Module B1: In-Use Emissions

To account for emissions released from building elements arising from the normal conditions of use and the impact of potential carbon absorption to be included. For example, emissions arising from refrigerants, insulation blowing agents, paints, etc. over the life cycle of the building.

Module B2: Maintenance Emissions

To account for emissions arising from the following building element categories – 

• Roof
• External walls
• Windows
• External Doors
• Finishes and Services (MEP)
• Additional items should be included as appropriate if specific information on their maintenance is provided. Emissions arising from activities relating to maintenance processes for the functional and technical performance of the building façade and building integrated technical systems, including cleaning, and products used are to be included.
• Minimum WLC Assessment scope on [B2] – Emissions from Façade maintenance to be included. The façade maintenance should minimally cover the cleaning and painting of the building. While the cleaning cycle may vary depending on many factors, where there is no specific qualifying data for items the following assumptions may be utilized.

Module B6 - Operational Energy Usage (Annual)

• Include emissions from energy use of building integrated systems as projected and/ or measured throughout the lifecycle of the project.
• Carbon emissions from non-building related systems e.g. ICT equipment, cooking appliances, specialist equipment, etc. should be included.
• All energy-generating units (renewable and non-renewable sources) located within the building site, regardless if they have other functions such as providing protection against rain and wind penetration to the roof, or façade, must be included in the assessment.
• Photovoltaic panels installed in the garden of the site, which do not form part of the building envelope but deliver energy for use in the building or as exported energy should be included in the assessment.

Module B7 - Operational Water Usage (Annual)

• Include all building-integrated water-consuming processes of a building under operation such as processes for drinking water, domestic hot water, irrigation of associated landscape areas, green roofs and green walls, water for heating, cooling, ventilation, and humidification, and other specific water use of building-integrated systems.
• Fountains, swimming pools, saunas. (Note: [B7] is excluded from the WLC assessment. Energy use associated with providing domestic hot water and other water-use-related systems is included in the module

Modules C1-C4: End-of-Life (EoL) Stage

The end-of-life stage of a building starts when the building is decommissioned and will no longer be used. The building is considered to have reached its end of life when all components and materials that were to be cleared from the site have been removed and the site is cleared for future re-use. The emissions arising from decommissioning, disassembly, deconstruction, and demolition works, including from transportation, processing, and disposal of materials at the end-of-life of the project must be accounted for. For the purpose of the WLC assessment, this EoL stage is assumed to occur at the end of the reference study period (RSP). EoL stage is considered complete within the WLC assessment scope when the site is levelled to the ground and is ready for further use.

Module C1 - Deconstruction and demolition emissions

Includes emissions arising from any onsite or offsite deconstruction and demolition activities. Energy consumption for site accommodation and plant use must be accounted for.

Module C2 - Transport emissions

Includes emissions arising from transportation of deconstruction and demolition to disposal and up to end of waste state. [C2] Transport carbon emissions for disposed waste items : [C2] = Mass of waste to be transported (a) x Transport emission factor (b) x Distance to disposal site [Note: Assume average heavy goods vehicle (HGV) with 50% load to account for vehicles coming to site empty and leaving with 100% load.]

Module C3 - Waste processing for reuse, recovery or recycling emissions

Includes emissions in treating and processing materials/ components intended to be recovered or recycled prior to reaching end of waste state. To develop EoL scenarios for each item. Data from relevant EPDs should be used, adjusted accordingly to suit the EoL scenario

Module C4 - Disposal emissions

Includes emissions of items not being recovered for reuse and/or recycling but intended for final disposal either in landfill or incineration. To develop EoL scenarios for each item. Data from relevant EPDs should be used, and adjusted accordingly to suit the EoL scenario.

Note: The majority of EPDs do not have EoL data as manufacturers are not required to report C1-C4 under the EN15804:A1 standard.

Module D - Reuse, recovery, and/or recycling potentials

• To calculate figures for module D, the figures should be reported as potential savings under module D, reported in kgCO2e/m2, and calculated
• For a particular component, (e.g. a steel beam), the figures for modules A1-A3 should be used plus an allowance for transport to the future site.
• For an entire structural frame that will remain on site for future reuse, the figures from both the product and construction stages should be used (modules A1-A5), plus an allowance against any avoided deconstruction, using the figures for modules C1, C2, and C4.

Factors and influences on the assessment

Carbon Sequestration

• Sequestered carbon can only be included in the impacts of the EoL stage of the WLC assessment if the timber is sustainably sourced – certified by FSC, PEFC, or equivalent. This is to ensure that any trees felled are being replaced with a minimum of the same number of trees planted to ensure they do not contribute to deforestation and do not compromise the overall carbon-absorbing capacity of forests.

Biogenic Carbon

• Through the process of photosynthesis, atmospheric carbon dioxide (CO2) is absorbed by the growing trees, and this absorbed CO2 is locked into timber as biogenic carbon until its EoL

Download LCA Results

1. Navigate to the results page, click on 'more actions', and download the detailed report. The results report has mass data on each of the categories as well which will be required for the Green Mark template.
2. Navigate to the results page and click on 'Download Results Summary' which will give you an excel report which has the results page table for easier copying into the Green Mark template.