Part L – What has changed?
Over the past year we’ve been hearing more and more about new ‘Part L’ building regulations and the industry has gone through a transitional period of focusing on researching and developing new products and services that will help architects and house builders meet the new regulations. But what exactly are Part L regulations?
Part L regulations focus primarily on the ‘conservation of fuel and power’ and place emphasis on the energy efficiency values of building elements. The Standard Assessment Procedure (SAP) used to measure compliance with these regulations calculates the dwellings overall efficiency taking many varying factors into account. Part L 2013 which was introduced in April 2014 includes a new set of targets called Target Fabric Energy Efficiency Rate (TFEE) which focus on the external envelope of a building’s design. It also sets out the requirements for SAP (Standard Assessment Procedure) calculations and Carbon Emission Targets for dwellings.
As attention now turns to achieving this Target Fabric Energy Efficiency Rate, the industry will now have to adopt a ‘fabric first approach’ to building design. Heat loss through 'thermal bridges' becomes more significant as this will have a detrimental effect on the buildings performance within SAP. By adopting this approach designers can achieve compliance following the recipe of recommended values within appendix R of SAP.
Fabric First Approach
This new requirement will see a major change in the way designers have to approach building design through specification of enhanced products and improving the dwellings fabric with an emphasis on improving thermal bridging. This is based on the principle of preventing energy waste by ensuring that the fabric of the building is energy efficient and is preferable to the use of costly bolt on renewables such as solar panels and heat recovery systems. The fabric of the building remains for the life time of the building therefore it will continuously perform as designed. It is very much in builder’s interests to seek out fabric first solutions since typically they offer simplicity in terms of buildability. Buildability is a big factor because complex solutions are notoriously difficult to implement efficiently onsite
Why is Lintel Choice Vital?
Lintels are one of the single most influential contributing factors which can affect a dwellings SAP calculation and Fabric Energy Efficiency. The thermal performance of a lintel is expressed in terms of psi value i.e. linear thermal transmittance which is calculated using specialist thermal modelling software. Openings for windows and doors are vulnerable to heat loss through thermal bridging. Improving the lintel value alone, can significantly improve performance within Part L, negating the need to upgrade the fabric elsewhere, or the need to add bolt on sustainability systems. It is essential therefore that specified lintels are able to demonstrate robust thermal performance, as well as fulfilling their primary function, to provide structural support. Part L is driving manufacturers to develop solutions to tackle this challenge.
As energy costs continue to rise, demand for energy efficient housing increases. Sustainability has a direct effect on the running costs of new homes. This will become more and more important to consumers in their choice of new homes. Builders therefore must continue to seek out new sustainable materials to meet these obligations. Furthermore consumers are more conscious than ever of the running costs involved in owning their own homes and for this reason Housebuilders will benefit by marketing energy efficient housing.
To learn more about Hi-Therm-Lintels please click here.