WWHR and SBEM

What is SBEM?

SBEM (Simplified Building Energy Model) is a software tool developed by BRE that provides an analysis of a building’s energy consumption.

SBEM is used for non-domestic buildings in support of the National Calculation Methodology (NCM), the Energy Performance of Buildings Directive (EPBD) and the Green Deal. The tool is currently used to determine CO2 emission rates for new buildings in compliance with Part L of the Building Regulations in England and Wales, and equivalent Regulations in Scotland, Northern Ireland, the Republic of Ireland and Jersey.

It is also used to generate Energy Performance Certificates for non-domestic buildings on construction and at the point of sale or rent.

What does SBEM do?

SBEM is used to do two things:

  1. To demonstrate compliance with Part L of the Building Regulations and
  2. To produce Energy Performance Certificates (EPC).

An SBEM calculation provides an output in the form of a ‘BRUKL’ report.

What is a BRUKL Report?

A Building Regulation UK Part L Report (BRUKL) demonstrates compliance with certain aspects of new build regulations, including a carbon emission target (TER/Target Emission Rate), solar gain and limiting standards for fabric and services.

The BRUKL document is required by Building Control prior to works starting on-site. The BRUKL document is mainly required for new builds (and, in some cases, extensions), but can also be used for existing buildings, if any of the minimum standards are not met, to demonstrate the CO2 has been compensated for elsewhere.

Why is SBEM needed?

Any building that is not considered a dwelling (hotels, leisure facilities, commercial properties) will require an SBEM calculation to be produced as part of the design process. Compliance with Part L of the Building Regulations requires energy modelling of building designs in order to demonstrate low carbon performance.

SBEM compared to SAP

SBEM and SAP (Standard Assessment Procedure) are essentially the same in assessing the design of a property against defined standards. However, SAP more accurately reflects the carbon emissions of domestic properties and SBEM, of non-domestic properties.

WWRH and SBEM

Calculations can be made as part of an SBEM model to assess the impact of Waste Water Heat Recovery for Showers, reducing the CO2 produced by a building. The calculation focusses on the hot water (DHW) usage for showers within the building to indicate the CO2 reduction that could be made through WWRHS introduction.

A DSM1 is produced to provide statistics for Domestic Hot Water (DHW) based on one of the NCMs2 (National Calculation Methodologies). The calculation uses these figures along with the total hot water energy demand for showers, the energy recovered from the shower, and the efficiency of the WWHRS to calculate the CO2 reduction due to the waste water heat recovery system. The WWHRS recovery efficiency will then be applied to the total DHW heating demand as deemed by the SBEM calculation.

Including waste water heat recovery in the design of a hotel, leisure facility or other commercial building with showers can provide a significant CO2 reduction through SBEM modelling, particularly when compared to other more expensive measures such as PV, ASHP or triple glazing.

Zypho® has a wealth of experience in assisting designers, architects and developers, incorporating WWHRS into both commercial and residential developments.

  1. Dynamic Simulation Modelling (DSM) is an extremely accurate and powerful tool for assessing the environmental performance of a building. Also known as thermal modelling, DSM can be used to model and analyse a range of sustainability factors typically arising from planning or building regulations drivers. These include energy compliance and CO2 emissions, overheating (thermal comfort) and daylighting analysis.
  2. The National Calculation Methodology (NCM) is a standardised framework developed to evaluate and calculate the energy performance of buildings. It offers a set of procedures, calculation methodologies and guidelines that enable accurate determination of energy consumption, carbon emissions and overall energy efficiency of a building. This calculation methodology is typically developed and implemented by governmental or regulatory bodies to ensure standardised energy assessments across the building sector. It provides a consistent and reliable method for assessing the energy efficiency of both new and existing buildings.

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