My plot missed the Part L planning deadline: What now?

Calendar missed deadline

My plot missed the Part L planning deadline: What now?

The old (2013) Part L Building Regulations for England apply to plots where plans were submitted before 15th June 2022, provided work is started before 15th June 2023. Where plans were submitted or work begins after these respective dates, the plot must comply with the updated Part L (2021). This is known as the ‘transitional arrangements’ period. Importantly, the regulations apply on a ‘per plot’ basis, not ‘per site’.  

So, what happens if you’ve designed a plot to Part L 2013 standards but missed the deadline for submitting your plans? 

no need to panic

If you’ve submitted plans after June 2022, your plot will have to comply with the new Part L Building Regulations. But that needn’t be as daunting as it sounds.  

Complying with Part L doesn’t have to mean lots of re-design work and the good news is that structural elements like cavity widths and the overall plot footprint can largely stay as they are. You’ll just need to think creatively about how you use the available space, to meet the new requirements.  

For example, loft insulation is a relatively cost-effective and easy way to increase the total thermal efficiency of a home. As loft spaces are often empty, they provide a good opportunity to fill the ‘dead space’ with insulation that goes above and beyond the minimum U-value requirements. 

Technologies such as rooftop photovoltaic panels are another option, for increasing the energy-efficiency of individual plots, without the need for large-scale redesign.  

Below is an example Part L compliant recipe*, showing one way this approach could be applied: 

5 bed detached, 3 wet rooms, 192m2, 5 occupants 

Your Next Steps

The important thing to remember when it comes to Part L, is that you have options.  

For further advice, speak to our Technical Support Team and determine the ideal route to compliance for your build. 

Use Knauf Insulation’s online U-value calculator Use Knauf Insulation's online Psi-value calculator 

Read our full Part L 2021 Guide