Environmental Report (Indicative)

For every submitted configuration, Alpha can compute an indicative environmental report: the amounts of material in the configured house, the CO2 emission and storage they represent, the environmental cost (MKI), and an MPG indication. Administrators find it on the configuration detail page and can download it as a branded PDF.

Indicative, not a validated MPG. Alpha is not an NMD-validated calculation instrument. The figures come from Alpha's own material catalogue, not from the Nationale Milieudatabase, and cannot be used for an omgevingsvergunning. The disclaimer is embedded in the UI and in every generated PDF.

How it works

1. The configuration's choices are resolved to the set of placed 3D models, exactly like the configurator and the render worker do. Each placed model instance counts once; a product placed twice contributes its materials twice.
2. Each model's linked product carries a material takeoff extracted from Revit (volume in m³ and area in m² per material name).
3. Material names are joined (case-insensitive) against the material catalogue (Construction → Materials data, the materials collection), which stores per material: density (kg/m³), CO2 emission and storage per kg, and MKI per kg.
4. Per material: mass = volume × density, then CO2 = mass × emission factor and MKI = mass × MKI factor.
5. The MPG indication follows the shape of the Bepalingsmethode: total MKI / (living area × 75 years), using the house's living area (gebruiksoppervlakte) and the residential 75-year reference period. It is n/a when no floor area is known or no material matched.

Where the floor area comes from

The MPG denominator is the house's woonoppervlakte, resolved in this order:

1. livingArea on the house: set it per BNR in the project editor (Design → BNR → Details → Woonoppervlakte), or let the 4PS sync fill it in: 4PS keeps the area on the house model (houseModels.surfaceLiving), which is matched to the plot via its house model, while plots.plotSurface fills the plot area. The sync only ever fills in a positive value, so a 0 from 4PS never wipes a value entered in Alpha.
2. The 3D model geometry: when no living area is set, the report falls back to the house's mass models (footprint per level, roof levels excluded), or to the house_width × house_depth × number_of_floors box when the type has no mass models. A fallback area is labelled "estimated from 3D model" in the UI and "geschat uit 3D-model" in the PDF; it is never presented as a measured value.

An estimate is only as good as the mass model, so entering the real woonoppervlakte remains the accurate route.

Data coverage

Materials without a catalogue entry (or with a catalogue entry missing density or impact data) are listed in the report but excluded from the totals. The coverage percentage shows how much of the total material volume is backed by environmental data; treat totals with low coverage as incomplete rather than low-impact.

Where to find it

• UI: configuration detail page (/configurations/{id}), "Environmental" card. Visible only for tenants with the Milieu (environment) scope enabled.
• PDF: download button on the card, or GET /configurations/{id}/environmental-report/pdf.
• API: GET /configurations/{id}/environmental-report.

Improving the numbers

The report is only as good as the material catalogue: add or complete materials (name matching the Revit material name, density, CO2 and MKI per kg) to raise the coverage. The catalogue supports public entries shared across tenants as well as tenant-private ones.