Inputs
Building use, area, element groups, assemblies, quantities, room geometry, glazing, location and study period.
Methodology
A transparent basis for early-stage whole-life carbon comparison.
CASCA turns available design information into comparable embodied carbon, operational energy, comfort and whole-life carbon outputs. The method is designed for option appraisal before a full project model is resolved.
Method overview
From early assumptions to comparable decision evidence.
CASCA keeps the calculation basis consistent so design options can be compared on direction, sensitivity and trade-offs rather than treated as isolated estimates.
Assessment basis
Declared material data, practical quantity rules, operational energy assumptions and room-scale simulation outputs.
Outputs
Embodied carbon, operational energy, comfort indicators, whole-life totals, intensities and rating-style context.
Review
Scenario comparison, hotspot review and transparent assumptions for design, research and teaching decisions.
Scope
Built for early option comparison, not final certification.
CASCA is intended for comparing facade, construction and building options while design choices are still open. It helps teams review likely direction and trade-offs without waiting for a fully detailed BIM, full LCA submission or compliance model.
- Shortlist and rank design options on a consistent basis.
- Test sensitivity to glazing, orientation, assemblies and internal gains.
- Review energy behaviour, peak periods and comfort risk.
- Produce early-stage embodied and whole-life carbon comparisons.
Boundaries
Clear limitations make the outputs easier to use.
CASCA does not replace formal project LCA, multi-zone whole-building energy modelling, mechanical design, system sizing or compliance reporting. Results should be used as structured early-stage evidence and reviewed against project-specific assumptions before formal reporting.
- Building workflow energy may be static or proxy-based unless project values are supplied.
- Room workflow is a simplified single-zone facade study.
- Module coverage depends on the selected source data.
Assessment routes
Two routes, one comparison logic.
The building workflow and room workflow use different levels of input detail, but both are arranged around transparent assumptions and comparable carbon outputs.
Building workflow
Whole-building option studies
Use gross internal area, building use, selected element groups, assemblies, quantities and operational energy assumptions to compare whole-building embodied, operational and whole-life carbon results.
- Foundations, superstructure, envelope and interiors can be included by element group.
- Quantities can be entered directly or derived from practical early-stage rules.
- Results are reported as totals, intensities, breakdowns and certificate-style outputs.
Room workflow
Facade, energy and comfort trade-offs
Use a single-zone shoebox model to test room geometry, facade orientation, room build-ups, window-to-wall ratio, glazing and internal gains.
- Weather-based simulation outputs support operational energy and comfort review.
- PMV/PPD and occupied-hour comfort outputs help identify facade-side comfort risk.
- Room-scale embodied and operational results are combined for whole-life comparison.
Lifecycle modules
Whole-life carbon modules are kept visible.
CASCA organises impacts around recognised lifecycle module terminology so users can see whether a result is driven by product-stage impacts, transport and construction, replacements, operational energy or end-of-life assumptions.
A1-A3 Product stage
Included where the selected material or assembly factor reports product-stage emissions.
A4-A5 Transport and construction
Included where the selected source explicitly declares these stages; otherwise they are not silently inferred.
B4 Replacement
Included when declared, or estimated transparently for selected facade/glazing assumptions where a service-life basis is used.
B6 Operational energy
Calculated from delivered or estimated annual energy and location-relevant carbon factors.
C1-C4 End of life
Included where declared, with conservative assumptions used only where the selected method states them.
Module transparency
Coverage depends on the data source, so assumptions and module boundaries should be reviewed before formal reporting.
Output interpretation
Results are designed for comparison and review.
CASCA outputs help teams understand relative performance, not just isolated numbers. The strongest use is comparing scenarios under the same location, study period, module boundary and reporting basis.
Embodied carbon
Material and assembly quantities are multiplied by the selected factor basis, then grouped into clear totals, intensities and module breakdowns.
Operational energy
Building workflow energy can use EUI, annual kWh, storey-based values or an EPC-style proxy. Room workflow outputs come from dynamic simulation.
Thermal comfort
Comfort charts should be reviewed with occupied-hour filtering where the question concerns occupant experience.
Carbon hotspots
Hotspot charts help users identify which element groups, modules or assumptions are driving the result.
Quality assurance
Compare like-for-like before drawing conclusions.
For robust option studies, scenarios should be checked against the same location, reference study period, carbon-factor basis and reporting units. Assembly factors should be reviewed for consistent units and declared module boundaries.
Recommended checks
- Confirm location, study period and carbon factor basis.
- Check quantity units and module coverage.
- Compare annual and monthly energy on the same basis.
- Review comfort headline metrics alongside time-series periods.