Enter the length of the exposed perimeter and the area of the floor into the calculator to determine the u value of the ground floor.

U Value of Ground Floor Formula

The following equation is used to calculate the .

U = .05 + 1.65*(P/A)-0.6*(P/A)^2

  • Where U is the u value
  • P is the length of the exposed perimeter of the ground floor
  • A is the area of the floor

The units of the area should be the square units of the length, i.e. ft and ft^2 respectively.

What is the U Value of a Ground Floor?


A U value is a measure of rate of heat loss per unit of area times degrees. It is used in building regulation to ensure buildings are not losing too much energy through the floor.

How to Calculate U Value of Ground Floor?

Example Problem:

The following example outlines the steps and information needed to calculate the U Value of Ground Floor.

First, determine the length of the exposed perimeter. In this example, the exposed perimeter is 100m.

Next, determine the area of the floor. This ground floor is measured to be 500m^2.

Finally, calculate the U value using the formula above:

U = .05 + 1.65*(P/A)-0.6*(P/A)^2

U = .05 + 1.65*(100/500)-0.6*(100/500)^2

U = .356