Daylighting and Part L

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Daylighting and Part L

04 Feb 2020
As expected, energy savings and carbon emissions reductions have dominated the discussions on the current Part L 2020 proposals, as well as debates about 'fabric first' vs renewable technologies.

Perhaps surprisingly given the increasing awareness of its importance in terms of health, well-being and productivity, daylighting has featured very little during industry meetings about the consultation.

In fact, in the consultation for new dwellings in England, there is a proposal that the supplementary guidance on daylighting from Approved Document L be removed, suggesting a demotion in its contribution to low energy buildings.  With an emphasis on reducing the risk of overheating in residential buildings – anticipated to be subjected to a separate consultation - there is a real concern that developers could be tempted to reduce glazed areas without considering the implications.  This could have a detrimental effect on the health and well-being of occupants.

As daylighting is important to both energy use, through the reduction of artificial lighting requirements, and occupant comfort, the glass industry should call on Government to retain the essential guidance on daylighting in the Approved Document.

Furthermore, in order to improve natural daylighting within new dwellings, a requirement should be introduced to Approved Document L.  This could be via a minimum glazed area of, say 25% of the total floor area, or an average daylight factor of 2% determined through calculation or modelling.

Among the noise around the Part L 2020 consultation, we should not lose sight of the important role that daylighting can make to delivering healthy and energy efficient buildings.

Visit our NEW Part L 2020 Hub 


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