U Value Insulation information
There are now different requirements for Replacement, Extension and New Build frames and doorsets.
Understanding that there IS a difference. We have to know the project type to give the best quotation & price compliant product.
U-VALUE AND WHAT IT MEANS TO YOUR PROJECT
The following information summarised from Building Regulations Documents L1A (New Dwellings) 2010 & L1B (Existing Dwellings) 2010.
| Fitting | (a) Standard for new fittings in new dwellings | (b) Standard for replacement fittings in an existing dwelling |
| Window, roof window and roof light | U-Value = 2.0W/m²K | U-Value = 1.6W/m²K or Window Energy Rating = Band C |
| Doors with more than 50% of their internal face area glazed | 2.0W/m²K | 1.8W/m²K (or exempt if fitted into existing door frame) |
| Other doors | 1.8W/m²K | 1.8W/m²K (or exempt if fitted into existing door frame) |
The following is general advice given by Jeld Wen:
What does it mean to our customers?
Part L 2010 Doors
Replacements & Doors in extensions (to existing dwellings)
- Maximum U-Value = 1.8 W/m²K where glazed area of door is less than 50% and fitted into a new frame. Exempt if fitted into existing frame.
- Maximum U-Value = 1.8 W/m²K where glazed area of door is greater than 50% and fitted into a new frame. Exempt if fitted into existing frame.
New build: Determined by Building Design
- U-Value (range) = from 1.1 up to 2.0 W/m²K (weighted average). We recommend that you consult with your architect for clarification.
Non Thermal Break (between a house and a heated porch)
- Exempt as insulation in this situation is not a requirement. The insulation comes from the porch door/windows.
Part L 2010 Windows
In simple terms:
Replacement windows
Maximum U-Value = 1.6 W/m²K or an Energy Rated window C or better (where A is best).
Extensions (excluding conservatories) to existing buildings
Maximum U-Value = 1.6 W/m²K
New build: Determined by Building Design
U-Value (range) = from 1.1 up to 2.0 W/m²K (weighted average).
Summary (for doors)
Is it a replacement? – Maximum U-Value of 1.8 W/m²K
Is it an extension to an existing building? – Maximum U-Value of 1.8 W/m²K
Is it a new build? – The customer must provide the U-Value but maximum allowable 2.0 W/m²K
