England & Wales Building Regulations: Part L: Conservation of fuel and power - Party wall thermal bypass (Version 1)

TRADA image

Approved Document L (ADL) 2010 is scheduled to come into effect in England and Wales in October 2010. There has been a number of changes throughout the document, ranging from improved backstop U-values, a requirement to increase the amount of air tightness testing and an overall improvement in the dwelling emission rate. All of these changes or improvements represent a significant increase from the 2006 requirements.

Prior to the 2006 edition of Part L, the thermal performance of a party wall was assumed to be 'perfect' (with a U-Value of 0.0 W/m²K) based on the fact that both sides are within the heated envelope of a building so there should be no temperate differential from one side to another.

One of the key changes to ADL2010 is that party walls must now be assigned a U-Value based on certain criteria, and that this U-Value is used in SAP calculations to determine a building's CO2 emissions.

This Construction Briefing discusses why the changes to Part L were necessary and what potential consequences for timber frame construction could be.

Contents:

  • Background
  • The requirement 
    • Table 1 - Approved Document L 2010 U-values for party walls
  • Effective edge sealing
  • Cavity insulation

Suggested Reading

Dynamic response of timber flitch beamsnavigation-arrow

Through experimental analysis, James Norman, Joel Ross, Robbie Kirkbride and Toby Hill-Smith outline the damping exhibited in these complex beams.

 

Article from Timber 2017 Industry Yearbook

01/03/2017 |  Magazine Article  

A motorway service station - but not as we know itnavigation-arrow

Exposed timber structures sympathetic to their rural surroundings are at the heart of a recently opened motorway service station in Gloucester.

 

Article from Timber 2018 Industry Yearbook

14/05/2018 |  Magazine Article  

Joinery: natural retreatnavigation-arrow

Outright winner of the prestigious Wood Awards 2017, the Coastal House is a showcase for the many uses of timber and some fine joinery.

 

Article from Timber 2018 Industry Yearbook

15/05/2018 |  Magazine Article