Maintenance Factor Table
Table rows for maintenance factor assumptions in maintained-lighting calculations.
MF 0.90
MF 0.80
MF 0.70
MF 0.60
Table PDFMaintenance Factor Table
Download the table with the page URL and retrieval date for offline lighting checks.
| MF band | Assumption | Effect on lumen target | Boundary |
|---|---|---|---|
| 0.90 | Clean maintained space with supported depreciation, access and cleaning evidence. | Required lumens = target lumens / 0.90 before UF. | Keep the evidence beside the estimate; this band should not become the default. |
| 0.80 | Ordinary preliminary allowance for controlled interiors with a plausible maintenance routine. | Required lumens = target lumens / 0.80 before UF. | Still an assumption, not a measured maintained-light outcome. |
| 0.70 | Dirt, ageing, access or maintenance uncertainty that may reduce delivered light. | Required lumens = target lumens / 0.70 before UF. | Use for sensitivity checks while the actual maintenance record is uncertain. |
| 0.60 | Severe depreciation, poor access, dusty conditions or weak maintenance evidence. | Required lumens = target lumens / 0.60 before UF. | Needs project-specific evidence before it is used in a design record. |
| Measured plan | Measured depreciation, cleaning interval, luminaire data and replacement records. | Replaces generic MF assumptions in formal maintained-light calculations. | Use the applicable source method and project record rather than a public-table shortcut. |