# Legacy Attributes

Use this guide to select Buildings v1 attributes and understand historical Dataset 3.1 enhancements. For the current `/v2/buildings` endpoints, use [Additional Properties](/guides/buildings/additional-properties).

Use `include` to request building attributes in one comma-separated query value, for example `include=centroid,elevation,footprint2d`. Use `all` to request all supported attributes. Data is returned when available.

## Choose attributes

| Value | Returned information |
| --- | --- |
| `area` | Building footprint area |
| `averageEaveHeight` | Average eave height |
| `centroid` | Building centroid coordinates |
| `elevation` | Building elevation |
| `estimatedLevels` | Estimated number of building levels |
| `footprint2d` | Two-dimensional building footprint |
| `footprint3d` | Building footprint with height coordinates |
| `maximumRoofHeight` | Maximum roof height |
| `overhangingTree` | Tree-overhang indicator |
| `roofComplexity` | Roof-complexity classification |
| `roofMaterial` | Primary roof material |
| `roofShape` | Roof-shape classification |
| `solarPanel` | Solar-panel indicator |
| `swimmingPool` | Swimming-pool information |
| `zonings` | Planning-zone classifications |
| `all` | All supported attributes |

Use the [legacy v1 reference](/reference/buildings-v1-buildings) for response models, measurements, and request requirements.

## Dataset 3.1 enhancements

Dataset 3.1 introduced more detailed attributes from higher-resolution aerial imagery. Request these legacy attributes with `include`. Current v2 additional properties have separate credit costs.

### Estimated levels

Dataset 3.1 improved building-level estimates using additional planning, building-type, and height information. Treat `estimatedLevels` as an estimate.

### Roof shape

The historical roof-shape definitions are:

| Shape | Meaning |
| --- | --- |
| Flat | A single horizontal plane |
| Hipped | Multiple sloping planes meeting at a ridge, with sloped ends |
| Gabled | Two sloping planes meeting along a ridge |
| Shed | A single sloping plane |
| Mansard | Multiple planes with sloping sections and a flatter upper section |
| Mixed | A combination of hipped and gabled shapes |
| Other | A shape outside those categories |

### Overhanging tree

`overhangingTree` indicates whether a tree was identified overhanging the building.

## Next steps

- [Start using the current Buildings API](/guides/buildings/quickstart)
- [Migrate legacy building fields](/guides/buildings/national-buildings-4-0)