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.

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