Sustainability Analysis
Đánh giá bền vững (LOTUS/LEED)
Compare design options on sustainability criteria (energy, water, materials, indoor comfort), supporting LOTUS, LEED, or Green Mark certification.
Common tools
IES-VE, DesignBuilder, Autodesk Insight, Green Building Studio
Value delivered
NATSPEC: sustainability analysis at early stage is 'more effective and efficient' than late-stage
Adoption in Vietnam
Fast growth driven by LOTUS (VGBC) adoption and FDI/international investor requirements.
Level of Information Need (LOIN)
G = Geometry · A = Alphanumeric · D = Documentation (ISO 7817-1:2024 method). A blank cell means this use sets no specific requirement for that discipline/stage.
| Discipline | Concept | Schematic | Developed | Technical | As-built / Operation |
|---|---|---|---|---|---|
| Architecture | G1·A1·D0 | G2·A2·D1 | G3·A2·D1 | — | — |
| Structure | — | — | — | — | — |
| Mechanical | — | G2·A2·D0 | G3·A2·D1 | — | — |
| Electrical | — | — | G3·A2·D1 | — | — |
| Plumbing | — | — | — | — | — |
Critical stages: Concept · Schematic · Developed
Rationale: ARCH-led (LOTUS / LEED / Green Mark, embodied carbon, material optimisation) starting at concept (G1/A1 is sufficient for orientation/massing tradeoffs). A2 from ST2 carries material environmental data; MECH/ELEC contribute system-efficiency data at ST3. D1 references rating scheme credits. Early engagement (ST1 entry) maximises influence on whole-life carbon at lowest cost of change.
What it really is
Sustainability Analysis uses data already in the BIM model — materials, envelope construction, glazing ratio, building orientation, MEP system parameters — to simulate energy use, daylight and embodied carbon from the design stage onward, then checks the results against the credits of a specific green building certification system. The three systems most common in Vietnam play different roles and should not be conflated: LOTUS, developed by the Vietnam Green Building Council (VGBC) specifically for Vietnam's climate and construction context; LEED from USGBC/GBCI, an international system often required by FDI investors to align with global ESG reporting; and EDGE from IFC (World Bank Group), which sets a simple bar — a minimum 20% savings in energy, water and embodied carbon in materials versus a local baseline — making it common for hotels and affordable housing seeking green finance. Unlike checking compliance with mandatory energy codes (covered under Code Validation), sustainability_analysis serves a VOLUNTARY certification, and its results are only trustworthy if the model carries enough detail to simulate — a model that is only good-looking geometry cannot be simulated at all.
When to use
Worthwhile when the appointing party genuinely intends to pursue a specific certification — for green finance, an FDI investor's ESG requirements, or brand positioning — and is willing to let simulation results actually shape design decisions from the concept or basic-design stage. It has little value if the goal is only a green label bolted on at the end of a locked design, or for works below the minimum floor-area threshold of the chosen system (LOTUS NC v3 applies from a gross floor area of 2,500 m² and above).
Prerequisites
- •Design Authoring completed at a LOIN sufficient for simulation — materials, envelope construction and orientation present; depends directly on Design Authoring
- •Certification system (LOTUS, LEED or EDGE) and target level chosen at the concept stage, recorded in the EIR/BEP
- •A sustainability/energy simulation specialist able to read and work directly with the BIM model, not just 2D drawings
- •Local climate data and a baseline-building methodology matching the chosen certification system
Inputs
Design task team · .rvt / IFC
Appointing party · .pdf / .docx
Energy simulation specialist · .epw
VGBC / GBCI / IFC, via the appointing party · .pdf / .xlsx
MEP task team · .rvt / .xlsx
Material supplier · .pdf
Outputs
Energy, daylight and embodied-carbon simulation report
.pdf + gbXML / .hbjson → Appointing party · certification specialist
Accepted when: Results follow the certification system's baseline method and are traceable to the source model version
Certification credit tracker
.xlsx → Appointing party
Accepted when: Every credit carries a pass/fail status with evidence, none left blank
Passive-design and system adjustment recommendations
.pdf → Design task team
Accepted when: Each recommendation is tied to a specific credit and carries a quantified impact
Complete certification submission package
.pdf / .zip → VGBC / GBCI / IFC
Accepted when: Complete documentation and evidence per the registered certification system's requirements
General workflow
Choose the certification system and target level
The appointing party and consultant decide which system (LOTUS, LEED or EDGE) and target level to pursue, registering with VGBC/GBCI/IFC where the system tracks progress. Record this choice and the LOIN for sustainability simulation in the BEP from the outset.
Appointing party · sustainability consultant · The certification system's registration form, not modelling software → Certification system and target level locked into the BEP
Prepare model data for analysis
Assign materials, envelope construction properties (U-value, solar heat gain coefficient), glazing ratio, orientation and space attributes to the design model. This step determines how reliable every downstream simulation will be.
Design task team + BIM Coordinator · Revit → Model carrying enough thermal and material properties to export for simulation
Run energy, daylight and carbon simulation
Export the model to simulation tools to calculate energy use, daylight and embodied carbon against the baseline building, following the chosen certification system's methodology.
Energy/sustainability simulation specialist · IES-VE, DesignBuilder for detailed energy simulation · Autodesk Insight Carbon Analysis (in Revit) and Autodesk Forma for early-stage embodied carbon and daylight → Energy, daylight and carbon simulation report
Check results against the credit checklist
Compare simulation results and design documentation against each certification credit, marking pass/fail and stating the gap for every credit not yet met.
Sustainability/certification specialist · The credit checklist published by VGBC/GBCI/IFC, not modelling software → Updated certification credit tracker
Adjust the design per the results
Return to the design model to change orientation, glazing ratio, envelope materials or MEP systems per the recommendations, then re-run the simulation — never edit the report's numbers to justify the old design.
Design task team · Revit → Design model updated per the sustainability recommendations
Compile the submission and track through to operation
Package the simulation report, credit tracker and design evidence into a submission for VGBC/GBCI/IFC; for systems requiring post-occupancy measurement, continue tracking actual consumption to retain certification.
Sustainability specialist · appointing party · The certification system's submission portal, not BIM software → Complete certification submission package
Diagram
↺ When the model changes, simulation runs again — the certification package is a consequence of the design, not a one-off exercise done separately at the end
Common pitfalls
Certification is registered and simulation run only after the design is locked, leaving no room to change orientation, glazing ratio or envelope materials
Cause: Green certification is treated as an end-of-project label rather than a design objective set from day one
Fix: Lock the certification system and target level at the concept stage and write it into the EIR/BEP, so simulation runs alongside — not after — the basic design
Energy/carbon simulation results are unreliable, and almost all data must be re-entered by hand into the simulation software
Cause: The model only reaches the information level needed for 2D drawings and lacks envelope construction properties, materials and glazing ratios needed for simulation
Fix: Define a specific LOIN for sustainability analysis in the BEP and assign thermal and material properties during authoring itself, not retrofitted at simulation time
The certification model and the main design model gradually drift apart with each revision, and the mismatch is only discovered close to submission
Cause: A separate energy model was built for simulation without a live link back to the original design model
Fix: Export simulations directly from the source design model and re-run them whenever the model changes, instead of rebuilding a standalone energy model
Measuring effectiveness
Count checklist credits whose evidence can be pulled from the model or model-linked simulation, divided by the total credits in the chosen system
Benchmark: Per a peer-reviewed literature review (citing Carvalho et al., 2020, secondhand — the original was not read): about 67% of LEED credits and 24% of BREEAM credits have been reported as BIM-linked in published studies. No equivalent figure exists yet for LOTUS or EDGE — use this only to calibrate expectations, not as a committed target
Compare the completion date of the first energy/carbon simulation round with the basic design approval date; the internal target is completion before approval, not after
Benchmark: no independent benchmark — set an internal target
Legal basis
There is NO specific requirement for sustainability analysis or green building certification (LOTUS, LEED, EDGE) in Decree 217/2026/NĐ-CP — sustainability_analysis falls under Article 8 generally. Art. 8(1)(a) makes BIM mandatory for new-build works Grade II and above; Art. 8(2) assigns scope, content and information requirements to the contract — the basis for bringing the LOIN for energy/sustainability simulation into the BEP; at appraisal, BIM data is submitted in the open IFC standard or another open format suited to the project's nature (Art. 8(3)(a)). The certification systems themselves are VOLUNTARY programmes run by an NGO (VGBC) or international bodies (IFC, USGBC/GBCI), not a Vietnamese statutory obligation — achieving one requires proactively registering and writing it into the EIR/BEP.
Sources
Only official sources (legislation, standards) and peer-reviewed academic work are cited. No vendor marketing figures or press sources. Reference only — does not replace legal advice.