Limiting fabric standards
Contents |
[edit] Introduction
The building regulations require that reasonable provision be made to limit heat gains and losses through the fabric of new buildings and works to existing buildings. The approved documents to the buildings regulations set out the limiting standards for the properties of the fabric elements of the building.
[edit] L1A, new dwellings, 2013 edition
Roof | 0.2 W/(m^2K) |
Wall | 0.3 W/(m^2K) |
Floor | 0.25 W/(m^2K) |
Party wall | 0.2 W/(m^2K) |
Swimming pool basin | 0.25 W/(m^2K) |
Windows, roof windows, glazed roof-lights, curtain walling and pedestrian doors | 2.0 W/(m^2K) |
Air permeability | 10.0 m^3/(h.m^2) at 50 Pa |
[edit] L2A, new buildings other than dwellings, 2013 edition
Roof | 0.25 W/(m^2K) |
Wall | 0.35 W/(m^2K) |
Floor | 0.25 W/(m^2K) |
Swimming pool basin | 0.25 W/(m^2K) |
Windows, roof windows, roof-lights, curtain walling and pedestrian doors | 2.2 W/(m^2K) |
Vehicle access and similar large doors | 1.5 W/(m^2K) |
High-usage entrance doors | 3.5 W/(m^2K) |
Roof ventilators (inc. smoke vents) | 3.5 W/(m^2K) |
Air permeability | 10.0 m^3/(h.m^2) at 50 Pa |
[edit] L1B and L2B, existing dwellings and existing buildings other than dwellings, 2010 editions
New thermal elements | Retained thermal elements | |
Wall | 0.28 W/(m^2K) | |
Pitched roof – insulation at ceiling level | 0.16 W/(m^2K) | 0.16 W/(m^2K) |
Pitched roof – insulation at rafter level | 0.18 W/(m^2K) | 0.18 W/(m^2K) |
Flat roof or roof with integral insulation | 0.18 W/(m^2K) | 0.18 W/(m^2K) |
Floors | 0.22 W/(m^2K) | 0.25 W/(m^2K) |
Swimming Pool basin | 0.25 W/(m^2K) | |
Wall – cavity insulation | 0.55 W/(m^2K) | |
Wall – external or internal insulation | 0.30 W/(m^2K) |
NB Approved Document C gives limiting values for individual elements to minimise the risk of condensation.
[edit] Related articles on Designing Buildings Wiki
- 2013 changes to the approved documents for part L of the building regulations
- Approved documents.
- Building Regulations.
- PA ratio.
- Part L.
- U-value.
[edit] External references
- Approved Document L1A: Conservation of fuel and power in new dwellings, 2013 edition.
- Approved Document L2A: Conservation of fuel and power in new buildings other than dwellings, 2013 edition.
Featured articles and news
Registered building inspectors
Building types and conflicts of interest updates explaineed.
Engineering services still struggle with labour shortages
According to latest quarterly services survey of the sector.
Infrastructure that connect the physical and digital domains.
Harnessing robotics and AI in challenging environments
The key to nuclear decommissioning and fusion engineering.
BSRIA announces Lisa Ashworth as new CEO
Tasked with furthering BSRIA’s impressive growth ambitions.
Public buildings get half a million energy efficiency boost
£557 million to switch to cleaner heating and save on energy.
CIOB launches pre-election manifesto
Outlining potential future policies for the next government.
Grenfell Tower Inquiry announcement
Phase 2 hearings come to a close and the final report due in September.
Progress from Parts L, F and O: A whitepaper, one year on.
A replicated study to understand the opinion of practitioners.
ECA announces new president 2024
Electrical engineer and business leader Stuart Smith.
A distinct type of countryside that should be celebrated.
Should Part O be extended to existing buildings?
EAC brands heatwave adaptation a missed opportunity.
Definition of Statutory in workplace and facilities management
Established by IWFM, BESA, CIBSE and BSRIA.
Tackling the transition from traditional heating systems
59% lack the necessary information and confidence to switch.
The general election and the construction industry
As PM, Rishi Sunak announces July 4 date for an election.
Eco apprenticeships continue help grow green workforce
A year after being recognised at the King's coronation.