How to Meet a 0.18 U-Value in Solid Floors

If you are currently in the process of insulating a concrete floor to meet building regulations, you may be required to reach a U-value of 0.18. It is quite common to aim for a U-value of 0.18 when insulating both domestic and non-domestic floors.

A common approach to achieve this low U-value is by using a generous layer of Rigid PIR Insulation. However, using a thick layer of PIR insulation can be expensive and may result in a loss of valuable head height.

What is a U-value?

A U-value is the measurement of heat loss and can measure the energy efficiency of an area such as roofs, walls, floors, and windows. The U-value decreases as the heat escaping from these areas reduces. When renovating a concrete floor or constructing an extension, it is crucial to ensure that the floor meets the required U-value.

The U-value is determined by calculating the total thermal resistance of all the layers that make the structure. For instance, in a roof, elements like tiles, membranes, air gaps, and timber can influence the U-value either positively or negatively.

How to Meet a 0.18 U-Value in Solid Floors using YBS SuperQuilt

2024 U-value Building Regulation

In June 2022 the current U-value targets were set, these can be viewed in the table below. For more information on Part L follow the link to the UK Government website – See Data Source.

U-value requirements for existing dwellings – 2022 onwards

Application Current U-value
Roof (Pitched & Flat Roof) 0.15
Wall 0.18
Floor 0.18

Here at Ecohome Insulation, we recommend using YBS SuperQuilt for insulating solid and concrete floors. SuperQuilt is a 40mm multifoil however, it compresses down to 7mm at its thinnest point. As well as Floors, SuperQuilt is certified for both walls and roofs. It’s made from 19 layers of true aluminium foil, recycled wadding, and PE foam.

YBS SuperQuilt equates to around 100mm Rigid Insulation in Floors, it’s fully agremont certified by BDA, manufactured in the UK, It’s free from any itchy or floating fibers, it’s made from 83% of recycled materials, it’s also Class E surface spread of flames.

How to Install YBS superQuilt to Achieve a 0.18 U-value

Below is our recommended build-up to achieve a 0.18 U-value;

  • Solid Concrete Floor
  • 1st Layer SuperQuilt laid flat on the floor
  • 50mm Battens with narrow centres
  • 2nd Layer SuperQuilt stapled taut over battens
  • 22mm Chipboard Finish
  • U-value achieved = 0.18 or lower

This detail will take up a total depth of approximately 86mm.

Going Through Building Control?

It is likely building control will want to see documentation. If so, we can help you out! Please use our Request a U-value form. Please mention the build-up of your floor as well as the m2 coverage.  We will then email a bespoke calculation and quote within 24 hours. (Monday – Friday)


Ecohome Insulation offers YBS SuperQuilt with FREE next-day delivery on all orders over £100 + VAT (UK Mainland).

YBS Superquilt can be purchased as loose rolls and is also available as a Trade Pallet Deal to save on cost.

Follow the links below to order online, you can also call us for more information.

YBS SuperQuilt Loose Rolls – Click Here

YBS SuperQuilt Trade Pallet Deal – Click Here


All build-ups and suggestions are provided in good faith. We recommend having these details double-checked by building control before proceeding. The U-value table is a guide, and your desired target U-value is to be advised by your building inspector. Please check the calculations for correct air gaps and battens, battens may be required to be installed perpendicular to how they are supplied in the image. 2D images are not to scale and are for illustrational purposes only. Multifoils-Direct cannot be held responsible for any losses financially as well as physically from the advice provided on this webpage.