1.3.2 Current model selector (actual, notional and reference buildings)
For the L2 (2021) ApacheSim regulatory framework a selector labelled ‘Bldg’ appears at the right-hand side of the VE Compliance toolbar. This allows you to switch between displaying the actual building, the notional building and (for EPC analysis) the reference building.
In most respects the actual building is the same as the ‘real’ building used in other VE views and Regulatory Frameworks. However, there are differences in the Room Data, where for L2 (2021) certain attributes assigned to the ‘real’ building are overridden by attributes representing the standard internal conditions stipulated for L2 (2021) in the NCM methodology.
The notional and reference buildings differ (in different ways) from the actual building in the following areas, in accordance with the rules set out in the NCM Modelling Guide:
· Glazing (and in some cases door) areas are adjusted.
· Standard constructions are applied.
· Where there are unheated buffer spaces (including unheated roofs) in the actual building, the notional building treats these as heat loss paths for adjacent heated rooms (following the principles laid down in BS EN ISO 13789:1999[2]). For these adjacencies standard constructions are applied, replacing the heat loss paths (including the unheated spaces) in the actual building.
· Apache Systems are assigned to rooms depending on the type of conditioning assigned to the rooms in the actual building.
By selecting ‘Notional’ or ‘Reference’ on the building selector, you can view the notional or reference building and interrogate its features. However, no editing is permitted. The notional and reference buildings are created automatically from the actual building and cannot be modified.
Trial simulations may be performed on the notional or reference building using the button labelled ‘CO2 emissions: test run (notional building)’ or ‘CO2 emissions: test run (reference building)’.
