With the new Part L 2014 Building Regulations coming into force, Chris Talford assesses the potential impact on design and costs.
New Part L 2014 Building Regulations come into force from 6th April and compliance with the revised regulations will have an impact on both the design and costs of a project.
One of the most significant amendments to the regulations is the introduction of the Target Fabric Energy Efficiency (TFEE) which measures the energy demand of a dwelling. This, along with a revised method of calculating the Target Emission Rate (TER), will form the assessment criteria of a proposed design.
The amendments made to the TER and the introduction of TFEE are reported to have resulted in an uplift in performance of 6% when compared to the 2010 Part L Building Regulations.
Another change in the Part L 2014 Regulations is the introduction of the ‘notional dwelling’. This sets out a worked example which includes set target U-values for the Walls, Floor, Roof and Windows/External Doors along with specifics on heating systems etc.
It is important to note that the backstop values in Part L 2014 remain practically the same as those in the 2010 regulations. This allows a certain amount of flexibility so long as the calculations do not drop below the backstop figures.
We investigated the cost implications of complying with the new Part L regulations by selecting a typical semi-detached dwelling originally priced to Part L 2010 standards and then revising the design to achieve the U-values set by the notional dwelling in Part L 2014.
This revised design incorporated increases in the type and thickness of floor and wall insulation whilst also introducing triple glazing in lieu of double glazing.
The data, when analysed, demonstrated that the impact of the Part L 2014 Amendments resulted in an overall increase of 3.5% in the construction costs of a project.