Construction layer data

Layers tab on Constructions Dialog.


You can select the way you would like to define the construction. The options depend on whether you are using EnergyPlus or SBEM Analysis type and whether it is a construction from the Floor (ground) or Below grade wall categories.


For EnergyPlus the allowable definition methods are:


Calculation Settings

Includes metal cladding

If the construction can be defined as a metal cladding system then you should check this option. This option affects linear thermal bridging at junctions involving surfaces made up of this construction.



Set the number of layers first, then select the material and thickness for each layer. Use the Controls in the Info Panel to insert and delete layers.  For example to delete a layer, first click on the material for the layer to identify which layer you want to delete, then click on Delete layer.


You can create constructions with up to 10 layers.


Note: You should not include surface resistance (film coefficient) layers to represent the resistance of the air films adjacent to the inner and outer surfaces. These are included automatically by DesignBuilder.

Layer order

You should define the layers in the same order they appear in the actual construction starting with the outermost layer and finishing with the innermost. The outermost layer will be positioned adjacent to outside (or in the case of Semi-exposed walls) adjacent to the Semi-exterior unconditioned zone.


For interior partition surfaces the order of the layers is not defined from the usage of the construction in a surface so the layer order is determined through a series of checks to see which zone is relatively ‘more external’. For example, if one zone is unconditioned and the other not then the partition layers are ordered so that the outermost layer is next to the unconditioned zone. When both zones are occupied, a similar check is made using heating and cooling setpoint temperatures. If after all these checks the zones are still both equally ‘internal’ then the direction of the layers will be set up in an arbitrary way.


Tip: When modelling an asymmetric partition between 2 zones that have identical zone type and heating and cooling setpoints and you need to specify the exact order of the partition layers, you can make a small difference in heating setpoint temperature between the 2 zones. For example consider the case of an occupied atrium zone adjacent to an office zone and the partition between the 2 has a thermal mass layer that must be adjacent to the atrium. This situation could be modelled by setting the heating setpoint of the atrium to be 0.1°C lower than the office and by making the thermal mass layer to be the outermost layer in the construction layer definition.


This field characterizes the thickness of the material layer. This is the dimension of the layer in the direction perpendicular to the main path of heat conduction.


Note: Modelling layers thinner (less) than 0.003 m is not normally recommended; rather, add those properties to one of the adjacent layers.


If the material referenced is defined as a simple R-value then the layer thickness does not affect the thermal performance of the construction.


If the material is defined as having a fixed thickness then the layer thickness is loaded automatically when the material is selected and the thickness does not have to be entered and cannot be edited.


You can add repeating thermal bridging to any layer to model the effect of a relatively more conductive material bridging a less conductive material.  For example wooden joists bridging an insulation layer.


Note: bridging effects are not yet used directly in EnergyPlus, but are used in energy code compliance checks requiring U-values to be calculated according to BS EN ISO 6946. However see below for a workaround to this limitation.