Building Elements Page
Use this as a guide to entering data on the Building Elements page.
A distinct building element should be created for each type of wall, floor, ceiling, door and window that exist within the property.
These building elements are then reused when creating a room to avoid repetition of entering the same data multiple times.
U-value Data Sources
The default U-value applied to each element will vary based on its category. See U-values & Thermal Bridging for more information regarding the reference source of the U-value.
Wall types
Walls types are added based on their category:
| Category | Description |
|---|---|
| External Wall | Walls that separates the dwelling from the outside |
| Internal Wall | Walls that partition rooms within the same dwelling |
| Party Wall | Walls that separate the dwelling from a neighbouring property |
| Known U-Value | Walls that have a measured or design U-value |
Original External Walls
Where the addition of an extension to the property means that an original external wall is now internally within the boundary of the property, it should still be added as an External wall type to produce an accurate U-value.
Known U-Value
When adding walls with a known U-value, you can also specify whether the U-value already accounts for ground contact.
This only affects basement walls and determines whether Annex E of the BS 12831-1:2017 standard will be applied or not, to calculate an equivalent U-value of elements in direct contact with the ground.
Floor types
Floor types are added based on their category:
| Category | Description |
|---|---|
| Ground Floor | Floors that separate the dwelling from the ground with unknown or no insulation |
| Ground Floor (known insulation) | Floors that separate the dwelling from the ground with known insulation level |
| Exposed Floor | Floors that separate the dwelling from an unheated space (e.g. garage) or outside air (flying freehold) |
| Internal Floor | Floors that separate different storeys within the same dwelling |
| Party Floor | Floors that separates the dwelling from neighbouring properties (flats/apartments) |
| Known U-Value | Floors that have a measured or design U-value |
Known U-Value
When adding floors with a known U-value, you can also specify whether the U-value already accounts for ground contact.
This only affects solid ground floors and determines whether Annex E of the BS 12831-1:2017 standard will be applied or not, to calculate an equivalent U-value of elements in direct contact with the ground.
Ceiling/roof types
Ceiling and roof types are added based on their category:
| Category | Description |
|---|---|
| External Roof | Ceilings that separate the dwelling from a loft or the outside air |
| Internal Ceiling | Ceilings that separate different storeys within the same dwelling |
| Party Ceiling | Ceilings that separates the dwelling from neighbouring properties (flats/apartments) |
| Known U-Value | Ceilings that have a measured or design U-value |
Door types
Door types are added based on their category:
| Category | Description |
|---|---|
| External Door | Doors that separate the dwelling from the outside |
| Internal Door | Doors that separate rooms within the same dwelling |
| Known U-Value | Doors that have a measured or design U-value |
Window types
Window types are added based on their category:
| Category | Description |
|---|---|
| External Window | Windows that separate the dwelling from the outside |
| Internal Window | Windows that separate rooms within the same dwelling |
| Known U-Value | Windows that have a measured or design U-value |