Heating swimming pools to maintain a consistent water temperature consumes energy. As part of reducing energy consumption and limiting the associated carbon emissions, national building regulations can require that swimming pool basins (the walls and floors of a pool) meet a certain threshold U-value.
To meet the U-value given in regulations, swimming pool basin design and specification must factor in thermal insulation. The type of insulation material and its characteristics can have a significant impact on certain design decisions, such as the shape of the pool and any slope in its floor.
Which country’s building regulations include swimming pool requirements?
Both volumes of Approved Document L in England, and both volumes of Approved Document L in Wales, contain references to the thermal performance of swimming pool basins. The technical guidance in both is the same.
At the time of writing, the Technical Handbooks in Scotland do not currently give technical guidance on swimming pool basins.
The Approved Documents in England and Wales specify a limiting U-value of 0.25 W/m2K for swimming pool basins. The thermal performance of the walls and floor of the pool should not perform worse than the limiting value, though they can perform better if desired.
However, both sets of Approved Documents also feature a specific paragraph saying the thermal performance of pool basins should not be included in energy rate and emission rate calculations. Instead, the area of the pool should be treated as having the same U-value as the surrounding floor.
This gives little incentive for pool basins to achieve a U-value lower than the limiting value of 0.25 W/m2K.
How should swimming pool basin U-values be calculated?
The English and Welsh Approved Documents both specify that the U-value of a swimming pool’s walls and floor should be calculated using BS EN ISO 13370:2017. This is the same standard used to calculate U-values for ground floor and basement constructions.
The calculation method is therefore the same whether the swimming pool under consideration is a small leisure pool in a private home or hotel, or a full-size competition-standard pool in a leisure centre or purpose-built sports facility.
Polyfoam XPS routinely carries out U-value calculations for ground floor and basement constructions, in accordance with BS EN ISO 13370:2017. We can therefore also calculate swimming pool basin U-values where required.
To find out more or to discuss your project in detail, contact us.