ASHRAE 90.1
Standard
Energy Standard for Buildings
Application area
US energy compliance
Project relevance
Appendix G performance rating method for beyond-code compliance demonstration.
Building performance
Energy modelling for informed design decisions
Hourly dynamic simulation, compliance modelling and parametric analysis supporting HVAC system selection, envelope optimisation and certification pathway verification.
Service scope
Energy modelling at SEINZEN uses dynamic thermal simulation to predict building energy performance before system selection and envelope design are fixed. Models are constructed from architectural geometry, proposed MEP systems and climate data to generate hourly load profiles, annual energy consumption and peak demand estimates.
Compliance modelling supports ASHRAE 90.1 Appendix G, EN ISO 52000, SBEM and project-specific certification pathways including LEED, BREEAM and local authority requirements. Baseline and proposed models are developed with documented assumptions traceable to design team inputs.
Parametric analysis evaluates design alternatives — glazing specification, insulation levels, HVAC system types and renewable integration — with results presented as comparative reports supporting design team decision-making. Uncertainty in inputs is acknowledged with sensitivity analysis where appropriate.
Model outputs inform HVAC equipment sizing, central plant capacity, utility connection requirements and lifecycle cost comparisons. Results are integrated with architectural and MEP design teams through documented review sessions.
Key engineering capabilities
Dynamic thermal simulation
Hourly energy models using IES VE, EnergyPlus or DesignBuilder with validated geometry and system inputs.
Compliance modelling
ASHRAE 90.1, Part L, EN ISO 52000 and local authority compliance models with baseline comparison.
HVAC load profiling
Heating, cooling and ventilation load profiles for equipment sizing and central plant capacity.
Parametric design analysis
Alternative scenario modelling for envelope, system and renewable options with comparative reporting.
Certification pathway modelling
LEED, BREEAM and WELL energy credit modelling with documented credit achievement verification.
Renewable energy assessment
Solar PV, solar thermal and ground-source heat pump yield modelling for integration studies.
Utility demand profiling
Peak demand and annual consumption estimates for utility connection and tariff assessment.
Lifecycle cost integration
Energy model outputs linked to capital and operational cost comparison for system selection.
Design team integration
Model review sessions with architectural and MEP teams to translate results into design decisions.
Design and delivery methodology
- 01
Modelling scope agreement
Simulation objectives, compliance targets, software selection and input data requirements agreed at project outset.
- 02
Baseline model development
Architectural geometry, envelope properties and baseline systems modelled per compliance protocol.
- 03
Proposed design modelling
Design team inputs incorporated with HVAC systems, lighting and renewables represented per current design.
- 04
Compliance verification
Baseline comparison, credit achievement and authority submission documentation prepared.
- 05
Parametric analysis
Design alternative scenarios modelled with comparative results supporting optimisation decisions.
- 06
Design integration
Load profiles and energy results communicated to MEP team for equipment sizing and system confirmation.
Technical design criteria
Simulation engine selection
EnergyPlus, IES VE Apache or DesignBuilder selection based on project complexity and compliance requirements.
Weather file selection
TMY, TRY or IWEC climate files matched to project location with future climate scenario consideration.
Envelope thermal properties
U-values, SHGC, thermal mass and infiltration rates from architectural specifications and test data.
Internal gain profiles
Occupancy, lighting, equipment and metabolic gains scheduled per space type and operating hours.
HVAC system representation
Ideal loads, detailed system templates or custom equipment models depending on analysis objective.
Baseline model protocol
ASHRAE 90.1 Appendix G or EN ISO 52000 baseline rules applied consistently for compliance comparison.
Renewable system modelling
PV array orientation, inverter efficiency and grid export assumptions for on-site generation assessment.
Uncertainty and sensitivity
Input parameter sensitivity analysis identifying variables with greatest impact on results.
Peak load vs annual energy
Distinction between peak demand for equipment sizing and annual consumption for operational cost.
Natural ventilation modelling
Mixed-mode and passive ventilation strategies with airflow network or CONTAM integration.
Engineering principles and calculation approaches
EUI = E_total / A_floor
Variables
EUI = energy use intensity (kWh/m²·yr); E_total = annual energy consumption (kWh); A_floor = conditioned floor area (m²)
Application
Building energy performance benchmarking against certification targets and code limits.
Notes
Separate fuel types by source energy or convert to equivalent primary energy per compliance protocol.
Savings = (E_baseline − E_proposed) / E_baseline × 100
Variables
Savings = percentage energy savings (%); E_baseline = baseline model consumption; E_proposed = proposed design consumption
Application
Compliance margin calculation for ASHRAE 90.1 and similar performance-based codes.
Notes
Apply protocol-specific baseline rules; document all credit-eligible measures.
Q_peak = Σ(Q_envelope + Q_internal + Q_solar + Q_ventilation)
Variables
Q_peak = peak cooling load (kW); components = envelope, internal, solar and ventilation gains
Application
Peak load verification from dynamic simulation against steady-state load calculations.
Notes
Dynamic peaks may differ from design-day steady-state; use simulation output for equipment sizing confirmation.
PV_yield = A_panel × G × η_panel × PR
Variables
PV_yield = annual generation (kWh); A_panel = array area (m²); G = annual irradiance (kWh/m²); η_panel = module efficiency; PR = performance ratio
Application
On-site solar PV generation estimation for renewable energy credit and utility offset.
Notes
Apply shading, soiling and temperature derating in performance ratio.
LCC = C_capital + Σ(C_energy / (1+r)^t)
Variables
LCC = lifecycle cost; C_capital = initial cost; C_energy = annual energy cost; r = discount rate; t = year
Application
Lifecycle cost comparison of design alternatives using energy model consumption outputs.
Notes
Include maintenance, replacement and escalation factors per project financial parameters.
Final design values must be determined using project-specific inputs, applicable standards, manufacturer data and engineering judgement.
BIM, Revit and integrated design
Architectural and MEP Revit models provide geometry and spatial data for energy model construction through gbXML export or direct integration.
Space boundaries, zone assignments and internal load data are extracted from BIM models with manual verification against design team inputs.
Model iteration tracks design changes with updated simulation runs comparing results against previous milestones.
Energy model assumptions and results are documented in project information delivery plans aligned to ISO 19650 data requirements.
International standards and codes
ASHRAE 209
Standard
Energy Simulation Aided Design
Application area
Simulation process
Project relevance
Standardised energy modelling process from early design through operation.
ISO 52000
Standard
Energy Performance of Buildings
Application area
International energy assessment
Project relevance
Overall energy performance assessment framework and EPB standards series.
EN ISO 52016
Standard
Energy Needs for Heating and Cooling
Application area
European load calculation
Project relevance
Hourly energy needs calculation for heating and cooling.
CIBSE TM54
Standard
Evaluating Operational Energy Performance
Application area
Operational energy
Project relevance
Bridging design-stage modelling with operational performance verification.
LEED v4.1
Standard
Energy and Atmosphere Credits
Application area
Certification
Project relevance
Optimise energy performance credit modelling requirements.
BREEAM Ene 01
Standard
Energy Performance Credit
Application area
Certification
Project relevance
EPC comparison and energy performance benchmarking for BREEAM assessment.
Part L (UK)
Standard
Conservation of Fuel and Power
Application area
UK building regulations
Project relevance
SBEM and dynamic simulation compliance for UK new-build and refurbishment.
ASHRAE 140
Standard
Standard Method of Test for Energy Analysis Computer Programs
Application area
Software validation
Project relevance
Bestest validation cases for simulation software accuracy verification.
IPMVP
Standard
International Performance Measurement and Verification Protocol
Application area
M&V
Project relevance
Measurement and verification framework linking design models to operational performance.
Climate Action Planning Standards
Standard
Local Authority Requirements
Application area
Planning compliance
Project relevance
Energy strategy and carbon reduction targets for planning submission.
ASHRAE 100
Standard
Energy Efficiency in Existing Buildings
Application area
Retrofit assessment
Project relevance
Energy audit and improvement assessment for existing building projects.
| Code | Standard | Application area | Project relevance |
|---|---|---|---|
| ASHRAE 90.1 | Energy Standard for Buildings | US energy compliance | Appendix G performance rating method for beyond-code compliance demonstration. |
| ASHRAE 209 | Energy Simulation Aided Design | Simulation process | Standardised energy modelling process from early design through operation. |
| ISO 52000 | Energy Performance of Buildings | International energy assessment | Overall energy performance assessment framework and EPB standards series. |
| EN ISO 52016 | Energy Needs for Heating and Cooling | European load calculation | Hourly energy needs calculation for heating and cooling. |
| CIBSE TM54 | Evaluating Operational Energy Performance | Operational energy | Bridging design-stage modelling with operational performance verification. |
| LEED v4.1 | Energy and Atmosphere Credits | Certification | Optimise energy performance credit modelling requirements. |
| BREEAM Ene 01 | Energy Performance Credit | Certification | EPC comparison and energy performance benchmarking for BREEAM assessment. |
| Part L (UK) | Conservation of Fuel and Power | UK building regulations | SBEM and dynamic simulation compliance for UK new-build and refurbishment. |
| ASHRAE 140 | Standard Method of Test for Energy Analysis Computer Programs | Software validation | Bestest validation cases for simulation software accuracy verification. |
| IPMVP | International Performance Measurement and Verification Protocol | M&V | Measurement and verification framework linking design models to operational performance. |
| Climate Action Planning Standards | Local Authority Requirements | Planning compliance | Energy strategy and carbon reduction targets for planning submission. |
| ASHRAE 100 | Energy Efficiency in Existing Buildings | Retrofit assessment | Energy audit and improvement assessment for existing building projects. |
Applicable standards depend on the project location, building use, authority having jurisdiction, employer requirements and contract documents. The current adopted edition must be confirmed at the beginning of each project.
Project deliverables and documentation
Energy modelling scope report
Simulation objectives, software, inputs and compliance targets documented.
Baseline energy model
Compliance baseline model per applicable protocol with documented assumptions.
Proposed design energy model
Design team model with current architectural and MEP system inputs.
Compliance report
Baseline comparison results with savings percentage and credit achievement summary.
Load profile reports
Hourly heating, cooling and ventilation load profiles for equipment sizing.
Parametric analysis report
Design alternative comparison with energy, cost and comfort trade-off analysis.
EUI and benchmarking summary
Energy use intensity comparison against certification targets and sector benchmarks.
Renewable energy assessment
On-site generation yield estimates and grid offset calculations.
Certification submission support
Documentation formatted for LEED, BREEAM or authority submission requirements.
Design team presentation
Results summary with recommendations for design integration decisions.
Sensitivity analysis
Input parameter impact assessment identifying critical design variables.
Model input/output archive
Complete model files, input data and results for audit and future reference.
Quality control and verification
Model inputs independently reviewed against architectural and MEP design documentation.
Baseline model verified against compliance protocol rules before proposed model comparison.
Simulation software version and weather file documented for reproducibility.
Results cross-checked against steady-state load calculations for peak load consistency.
Parametric analysis scenarios reviewed with design team before report issue.
Certification submission documents verified against current credit requirement versions.
Applicable project types
Commercial towers targeting LEED or BREEAM certification with performance-based compliance.
Mixed-use developments requiring planning authority energy strategy submission.
Healthcare and laboratory buildings with high ventilation loads and 24-hour operation profiles.
Data centres with continuous cooling load and PUE optimisation requirements.
Retrofit projects assessing improvement measures against operational baseline consumption.
Educational campuses with varied building types and central plant optimisation studies.
Frequently asked questions
When should energy modelling begin in the design process?
Concept-stage modelling supports early system and envelope decisions. Compliance modelling typically requires schematic design inputs. ASHRAE 209 defines modelling stages from early design through operation.
What simulation software is used for energy modelling?
IES Virtual Environment, EnergyPlus and DesignBuilder are used depending on project requirements and compliance protocol. Software selection is agreed at modelling scope stage.
How do energy model results inform HVAC equipment sizing?
Hourly load profiles from dynamic simulation provide peak and part-load data for chiller, boiler and AHU sizing. Results are compared with steady-state load calculations and discrepancies investigated.
Can energy modelling support planning authority submissions?
Energy strategy reports, EUI benchmarks and carbon reduction demonstrations are prepared for planning submission where local authority requirements apply.
What is the difference between compliance and design optimisation modelling?
Compliance modelling follows protocol-specific baseline rules for code or certification verification. Design optimisation modelling evaluates alternatives to inform system and envelope selection without protocol constraints.
Discuss energy modelling scope
Contact our building performance team to review simulation requirements, compliance targets or parametric analysis for your project.