How to treat ceiling void in the EPC DSM calc

[Blackeagle]

Hi,

I am wondering if you could let me know your experiences about the correct way of doing or treating ceiling void the DSM calculation ?

Question: can I create a separate zone for the purpose of ceiling void/services void in EPC calculation for level 5 project carried via DSM tool?

I am aware that SBEM and EPC conventions require unconditioned zones that are adjacent to the heated spaces will need to be absorbed into heated area , and void should be included within the construction between conditioned and unconditioned zone , but this is the rule for SBEM EPC since I assume it is only applicable to this tool due to its simplicity or a limited approach to energy calculation procedure .

Also , IES does not support U value information reported in the BRUKL document for the area set as warm rood /internal void , you will need to create geometry by following EPC convention method to avoid this problem however there is no problem for the criterion 2 if you proceed the same calculation with DSM tool( even you set the service void/roof void as internal void ) so it is supposed if you do this way ,
does this mean I am allowed to create geometry as it appears in the architectural drawing ( with void , pitched roof with various angle) ?? ( provided that I set adjacent space to that unconditioned space , by doing so I assume this should bring whole calculation carried out with DSM in line with EPC calculation)

keeping the ceiling void /or unconditioned especially becomes important if you are using the same model/geometry created for purpose of thermal model or design calculation , this can avoid alteration of the model to suit EPC convention ( although you can start creating the geometry by including void into adjacent heated space , it is not preferable for a situation where infiltration losses becomes high as a result of increased room volume )

I would be appreciated if those ,who are member of CIBSE epc accreditation scheme , can share their experiences when they treat uncondioned zones in their Level 5 DSM calculation