Building Regulations Construction Data
Part L (2013-2014) requires certain attributes to be entered for constructions in addition to the data required for other thermal calculations. This data is entered in the constructions database program CDB. The additional attributes (broken down by construction category, and including attributes required for Part L1 (dwellings)) are:
Glazing
Display window?
Tick this box if the window is a display window. Such windows are exempt from certain L2 (2013) requirements.
Frame material and percentage
Select a frame material from the drop-down list and consider the % frame value.
Doors
Door type
Select from the following types:
- personnel door
- vehicle access or similar large door
- wall or roof element that is not to be treated as a door for the purposes of Part L
- smoke vent
- high usage entrance doors
Doors of types b, d and e form special categories in Part L. Type c is provided to allow door drawing facilities in ModelIT to be used to create wall or roof elements.
Ground floors
Ground floor U-values can be calculated using a floor area / perimeter method.
- Floor area
- Enter the ground floor area
- Exposed floor perimeter
- Enter the exposed floor perimeter
- External wall thickness
- Enter the wall thickness of the external wall that bounds the floor perimeter.
- Ground conductivity
- Enter the conductivity of the ground below the ground floor
All construction categories
Thermal bridging coefficient
Part L2 (2013-2014) requires an allowance to be made for non-repeating thermal bridging. In the VE implementation this is handled via a coefficient expressing this component of heat loss as a multiple of element area. This can be thought of as an addition to element U-value. The default value of is 10% of the constructions u-value.
In the notional building, thermal bridging coefficients are set to standard values laid down in the NCM Modelling Guide.