PartL2(2013-2014)VE-SBEM

 

This document makes references to ‘Part L2 (2013/2014) VE-SBEM’ throughout.  Specifically, this is intended to cover both:

·       Part L2 (2013) – England

·       Part L2 (2014) - Wales

Part L2 (2013/2014) VE-SBEM is a facility within the VE Compliance View which provides the means to test compliance with Part L2 of the Building Regulations (2013 England edition, in force from 6 April 2014, 2014 Wales edition in force from 31^st July 2014) and to generate Energy Performance Certificates (EPCs) for non-domestic buildings within the same framework, using BRE’s Simplified Building Energy Model (SBEM). An alternative route to compliance  based on use of the ApacheSim dynamic simulation model (DSM) is also provided within VE Compliance, and documented in other user guides (for example PartL2(2013)ApacheSim.pdf).

Part L2 (2013/2014) VE-SBEM applies to new buildings other than dwellings in England and Wales.

Data for the VE-SBEM analysis is taken from the Virtual Environment model, supplemented where necessary by inputs specific to the requirements of the selected Regulation. This data is used to write an input file for the BRE tool SBEM v5.2d. The Virtual Environment launches the BRE SBEM tool with the input data file and the BRE SBEM tool runs calculations to either perform a compliance assessment or generate an EPC.

 

Results of the VE-SBEM analysis can be found via the VE Compliance menu option >> ‘View results folder’ and are presented as follows

1.       Compliance document (PDF file) plus Calculation Summary (one page of graphs as a PDF file) and Calculation Details (more detailed breakdown as a HTML file)

or

2.       Energy Performance Certificate (PDF) and Recommendations Report (PDF).

A XML file is also generated for lodgement in the official database.

This user guide covers software facilities in the Virtual Environment for testing compliance with the 2013/2014 edition of The Building Regulations and for generating EPCs within the same framework.

The requirements of The Building Regulations Part L2 (2013/2014 edition) as applied to new buildings are set out in Approved Document L2A^[1].  This document should be consulted to better guide any submission for Part L2 compliance. 

Details on what an approved document is and how it should be used is set out in the document introduction including ‘What is an Approved Document?’ section.

 

It’s important to note the both England and Wales refer to separate L2A document:

 

 

 

 

 

The broad requirements of L2 are set out in the Requirement section of Approved Document L2A^[1] (referred to in this document as ‘L2A’). They cover:

 

 

The detailed requirements are outlined in Section 1: The Requirements, under the heading demonstrating compliance. Five criteria must be satisfied (paragraph numbers refer to L2A):

 

 

 

L2A should be consulted for details of special considerations and exemptions applying to particular classes of buildings.

Some of the requirements of Part L2 cannot be tested in software (Criteria 4 and 5 fall into this category).

The requirements tested by the software are Criteria 1 to 3, which are implemented in the software as follows.

 

The BER and TER values are obtained from the simulated carbon dioxide emissions of two buildings.

 

The ‘actual building’, which forms the basis of the BER calculation, is the building as designed, but subject to standard operating conditions dictating levels and patterns of occupancy, internal gain and minimum ventilation.

 

The ‘notional building’, which forms the basis of the TER calculation, is a version of the actual building modified in accordance with rules relating to glazing area, insulation, system efficiency and other factors. The notional building is also subject to the standard operating conditions. The notional building is created within the BRE SBEM tool.

 

Both buildings have monthly heat balances performed for standard weather data appropriate to the building location. Results are automatically fed into the BRUKL compliance calculator provided by BRE.

 

The standard operating conditions are functions of the building type and the activities occurring within each room. They are laid down in the National Calculation Methodology (NCM) Modelling Guide^[3].

Criterion 2 imposes constraints on U-values and other aspects of building and system performance.

 

Limiting fabric standards (U-values) for fabric elements are stated. The software applies checks for compliance with this requirement before performing the actual and notional building simulations.

 

Limiting services efficiencies are also laid down in the following areas:

·       Controls

·       System efficiencies

·       Energy Meters

·       Centralised switching of appliances

 

Others limiting services efficiencies are also suggested in the DCLG Non-Domestic Building Services Compliance Guide and include;

·       Heating and hot water service systems

·       Cooling plant

·       Air handling plant

·       Insulation of pipes, ducts and vessels

·       Lighting

This criterion seeks to limit the solar gains to spaces during the summer period with the aim of

·       Reducing the need of air-conditioning; or

·       Reducing the installed capacity of any air-conditioning system that is installed.