Area Weighted U-Value Calculator |
||||
Project Addess |
||||
Actual Extension |
||||
Net Area (m²) |
U-value (w/m²k) |
Heat Loss (W) |
Proportion of Total |
|
External Walls |
- |
|||
Roof - Insulation at rafters |
- |
|||
Roof - Flat Roof |
- |
|||
Roof - Insulation at joists |
- |
|||
Ground Floor |
- |
|||
Windows |
||||
Roof Windows |
||||
Doors |
||||
Totals |
- |
|||
Area weighted U-value |
||||
Notional Allowance Calculator |
||||
Floor Area of Extension |
m² |
|||
25% of extension floor area |
m² |
|||
Area of openings removed as a result of the extension |
m² |
|||
Total Glazing Allowance |
m² |
|||
Notional Extension |
||||
Net Area (m²) |
U-value (w/m²k) |
Heat Loss (W) |
Proportion of Total |
|
External Walls |
0.28 |
- |
||
Roof - Insulation at rafters |
0.18 |
- |
||
Roof - Flat Roof |
0.18 |
- |
||
Roof - Insulation at joists |
0.16 |
- |
||
Ground Floor |
0.22 |
- |
||
Windows |
1.60 |
|||
Roof Windows |
1.60 |
|||
Doors |
1.80 |
|||
Totals |
- |
|||
Area weighted U-value |
||||
Compliance Results |
||||
Part 1 - Paragraph 4.1, AD L1B 2013 (England) |
||||
External Wall u-value compliant? |
||||
Slope Roof u-value compliant? |
||||
Flat Roof u-value compliant? |
||||
Plane Roof u-value compliant? |
||||
Ground Floor u-value compliant? |
||||
Window u-value compliant? |
||||
Roof Window u-value compliant? |
||||
Door u-value compliant? |
||||
Part 2 - Paragraph 4.5, AD L1B 2013 (England) |
||||
Actual area weighted u-value |
||||
Notional area weighted u-value |
||||
Compliance Achieved? |
||||
This online tool gives an indication of how an extension could comply using the Area Weighted U-Value Method Described in Building Regulations Part L1b. Briary Energy supply this tool FOC to help homeowners and architects design buildings to comply with Part L. |