GreenRaft Insulated Slab Foundation U-Value and Cost Quote Calculator
This calculator allows you to find the u-value for a typical GreenRaft insulated foundation slab and is consistent with BS EN ISO 13370:2017. Enter the required information into the first section of the form to see the calculated u-value in the green box.
The process for calculating the u-value of a floor which is in contact with the ground is much more complicated than for suspended floors, walls and roofs which are surrounded by air on either side. This is because the ground has a significant effect on the heat transfer through the slab. The heat transfer is multidimensional which makes it more difficult to approximate and therefore calculate than for other building components. As a result of the multidimensional heat transfer most of the heat loss occurs at the edge of the slab whilst nearly none is lost through the middle. Because of this effect, the ratio of exposed perimeter to overall slab area is one of the most important factors in the calculation. A smaller perimeter to area ratio will make for a smaller u-value.
To receive a cost quote for your project, please fill out both sections of the form below and press the submit button at the bottom. Upon submission, a quote for supply of GreenRaft materials will be emailed to you along with estimates for other associated costs. Providing that all details are entered correctly, the quote will be valid for 90 days from the date of submission.