# Heat loss due to linear thermal bridging

In physics, $H_TB$ is the heat loss due to linear thermal bridging when calculating the energy performance of buildings. It appears in both United Kingdom[1] and Irish[2] methodologies.

## Calculation of $H_TB$

[3]

The calculation of the heat loss due to linear thermal bridging is relatively simple, given by the formula below:

$H_TB = y \sum A_{exp}$

In the formula, $y = 0.08$ if Accredited Construction details used, and $y = 0.15$ otherwise, and $\sum A_{exp}$ is the sum of all the exposed areas of the building envelope,

## References

1. ^ "User Manual, JPA Designer" (PDF). JPA Technical Literature. Archived from the original (PDF) on 2007-10-08. Retrieved 2007-07-06.
2. ^ "Dwelling Energy Assessment Procedure". Sustainable Energy Ireland. 2006. Archived from the original on 2007-09-28. Retrieved 2007-07-06.
3. ^ "Steel Construction and Thermal Bridging". British Constructional Steelwork Association. Retrieved 2007-07-06.