- Project plans
- Project activities
- Legislation and standards
- Industry context
- Specialist wikis
Last edited 17 Feb 2021
National Calculation Method NCM
The National Calculation Method (NCM) is defined by the Department for Communities and Local Government (DCLG). It describes the procedure, for buildings other than dwellings, for demonstrating compliance with the carbon emission requirements of regulation 17C of the Building Regulations and for calculating ‘operational ratings’ and ‘asset ratings’ in the production of Energy Performance Certificates (EPC’s) in relation to the Energy Performance of Buildings Directive (EPBD).
The NCM provides the underlying method and the standard data sets necessary to calculate the annual energy use of a proposed building and comparing it with the energy use of a ‘notional' building of a similar type, under similar circumstances. This is done by calculating the Target Emission Rate (TER - the CO2 emission rate) for the notional building and comparing it with the Building Emission Rate (BER) for the proposed building. The BER must not be higher than the TER.
The calculations can be performed using approved simulation software (Approved Dynamic Simulation Models (DSMs)) or by using the Simplified Building Energy Model (SBEM), a ‘simplified’ compliance tool developed by BRE, which has a user interface called iSBEM.
 Related articles on Designing buildings Wiki
- Approved building energy calculation software.
- Approved documents.
- Building Regulations.
- Dynamic Simulation Model.
- Emission rates.
- Energy Performance Certificates.
- Energy Performance of Buildings Directive.
- Passivhaus vs SAP.
- Simplified Building Energy Model.
- Standard Assessment Procedure.
 External references
Featured articles and news
Advancing sustainable and regenerative project management.
Promised to be pragmatic and practical guidance.
Whilst replacement maybe preferred, its not always possible.
Dealing with draughts and reducing heat loss.
Managing Partner at Onyx and third gen project manager.
Expectation types, management and performance gaps.
Appointments, re-appointments and six changes a year.
New ways to manage the housing crisis.
Consortium seeks signatories for open letter by February 29.
Meaning, understanding and implementation.
From climate to cost to cold bridges and design flexibility.
In a changing world at the APM PM SIG conference.
The glass product that opened up new possibilities.
Campaigning for buildings of all periods.
Get to know the new requirements and the new terms.
The ultimate companion for building services excellence.