Carbon Designer 3D can estimate a building's operational energy use and the carbon emissions that come with it, alongside embodied carbon, at early design stage. This lets you compare design options on both embodied and operational impacts before detailed energy modelling is possible.
Operational energy is available for supported reference buildings and building types in Norway, Finland, Ireland and the UK.
How it works
Operational energy uses information you already enter when you create a design, so there is no extra setup.
Create a design. In Step 1, select the reference building and building type.
An energy scenario is assigned. In Step 2 (Select the scope), Carbon Designer 3D automatically assigns an energy scenario when one exists for your reference building and building type. The scenario holds predefined assumptions for electricity, primary heating, secondary heating and cooling.
Generate your building. Complete the remaining steps as usual.
Review the results. Carbon Designer 3D calculates annual energy demand, purchased energy and operational carbon emissions, and shows them in the Energy table and graph.
Adjust the scenario if needed. Change assumptions or add energy resources directly in the Energy table to reflect your project.
Save to your project. When you save the design, energy results become available in the project's queries and results.
If no energy scenario exists for your combination of reference building and building type, the energy section does not appear in Step 2 and no operational energy results are calculated.
Supported regions and building types
Energy scenarios represent typical building performance and energy systems for each region and building type. They are available for the combinations below.
Region | Reference buildings | Energy scenarios | Building types |
Finland | Finnish reference building; Finnish reference building (CO2data.fi data); Finnish free version reference building | Kerrostalo; Pykälä Kerrostalo; Pientalo; Pykälä Pientalo | Apartment building; One dwelling building |
Ireland | Irish reference building | Irish energy scenario | Offices; Retail building; Hotels; Hospitals; Social welfare building; School primary; General educational building; One dwelling building |
Norway | Norwegian reference building (with Lavkarbonbetong data); Norwegian reference building v2.0 BETA; Norwegian DFØ 2023 reference building; Norwegian DFØ 2026 reference building | TEK17; TEK10; Passivhus | Apartment building; Offices; Retail building; Hotel; Hospitals; Prison; General educational building; School primary; Sport hall; Cultural building; Industrial building; Social welfare building; One dwelling |
UK | UK reference building; UK RICS v2 reference building | UK energy scenario | Apartment building; Offices; Retail building; Hotels; Hospitals; One dwelling building |
For how reference buildings are built and which data they use, see Carbon Designer 3D: Reference buildings and data sources.
Understanding the Energy table
The Energy table appears with your design results. It shows the assumptions behind each energy category and the results they produce.
Energy categories
Each scenario covers four categories: electricity, primary heating, secondary heating and cooling.
Inputs
Input | What it means | Unit |
Resource | The energy source used for the category, such as district heating or grid electricity |
|
Demand per area | Energy needed per square metre of heated floor area each year | kWh/m²/year |
Conversion efficiency | How efficiently the system turns purchased energy into delivered energy | ratio |
How results are calculated
Annual energy demand is the heated floor area multiplied by the demand per area:
\text{Annual energy demand (kWh)} = \text{Heated floor area (m}^2\text{)} \times \text{Demand per area (kWh/m}^2\text{/year)}Purchased energy accounts for the conversion efficiency of the system:
\text{Purchased energy (kWh)} = \frac{\text{Annual energy demand (kWh)}}{\text{Conversion efficiency}}Carbon emissions are then calculated from the purchased energy and the carbon intensity of each energy resource.
Outputs
Output | What it shows |
Annual energy demand | Energy the building needs per year, per category |
Purchased energy | Energy bought per year after conversion losses |
Carbon emissions | Operational carbon from each category |
% of total | Each category's share of total operational emissions |
Carbon intensity per unit | Emissions per kWh of the selected energy resource |
Adjust the energy scenario
The assigned scenario is a starting point. You can change it to match your project's energy strategy and compare options without detailed energy modelling.
Change assumptions: edit the demand per area or conversion efficiency for any category in the Energy table.
Add energy resources: click + Add resources in the Energy table to include another energy source, for example on-site renewables or a different heating system.
Results update when you save the design. To compare energy strategies, copy the design, change the scenario in the copy and compare the two side by side.
Good to know
Early-stage estimates, not energy modelling. Scenarios reflect typical performance for the region and building type. Use them to compare options at concept stage, and replace them with project-specific energy data as the design develops.
Life-cycle stage. Operational energy is reported as B6. Operational water use (B7) is not included.
Heated floor area drives demand. Annual energy demand is based on the heated floor area, so whether underground floors are heated or unheated in Step 3 affects your results.
Coming from Carbon Designer Classic? Carbon Designer 3D uses the same energy scenarios, with updated energy profiles and resources.
Frequently asked questions
Why don't I see the energy section in Step 2?
No energy scenario exists for your combination of reference building and building type. Check the supported combinations in the table above.
Can I use operational energy outside Norway, Finland, Ireland and the UK?
No. Energy scenarios are currently available only for supported reference buildings in these four countries.
Can I change the energy assumptions?
Yes. You can edit the assumptions for any category and add energy resources directly in the Energy table.
Do energy results carry over to my project?
Yes. When you save the design to your project, energy results become available in the project's queries and results.
Does this replace a detailed energy simulation?
No. It gives a fast, typical-performance estimate for early design decisions. For compliance or detailed design, use project-specific energy data.
Related articles
Article | Read it when |
You are new to Carbon Designer 3D or want the full workflow | |
You want to know how regional baselines are built and which data they use | |
Your building mixes uses, has floors of different sizes, or includes parking or underground structures | |
You already have an IFC model of the building |