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Industry Standard Update 078

Industry Standard Update 078:
Amendments to the Domestic Building Services Compliance Guide – 2018 – England. Date issued: February 2018

Overview of the changes to the 2013 editions of the Domestic and Non-Domestic Building Services Compliance Guides for England, both of which come into effect on 6 April 2018.

Introduction
During April 2018, the government published amendments to the 2013 edition of the Domestic Building Services Compliance Guide(1) for England. Copies of this document, which are Crown copyright, can be downloaded free at: https://www. planningportal.co.uk/info/200135/approved_ documents/74/part_l_-_ conservation_of_fuel_and_ power/5

General
The revised guidance for England comes into effect on 6 April 2018, with the following exceptions – where the earlier edition of this guidance continues to apply:

  • Work started on site before this date
  • Work subject to a building notice, full plans application or initial notice submitted before this date, provided that it is started on site before 1 October 2018, or
  • Work where a contract for installation was agreed before 6 April 2018 and work is started on site before 1 October 2018.

For other jurisdictions in the UK, it will be necessary to consult the relevant Building Regulations and guidance.

Section 1.7: Work on existing systems
Paragraph 2 of Section 1.7 has been amended to state: “When replacing a boiler, the boiler controls are considered to be a part of the boiler installation and should therefore meet the standards set out in the relevant sections of this document. For gas-fired combination boilers, certain energy efficiency measures are also considered to be part of the boiler installation and should meet the standards as set out in Section 3.”

Section 1.8: Replacement of primary heating appliances
For gas-fired boilers, a minimum energy efficiency standard applies to the replacement appliance. For gas and oil-fired boilers, the installation of a replacement appliance should also include adequate controls. For gas-fired combination boilers, the installation of a replacement appliance should also include additional energy efficiency measures. Details of these requirements can be found in Section 2 for gas-fired boilers and Section 3 for oil-fired boilers.

Table 1
The following amendments have been made to Table 1:
• In the “Gas-fired wet central heating” section, under “Seasonal efficiency”, a column has been added to provide guidance on “ErP”.
• A further row has been added to the “Gas-fired wet central heating” section. The first column of this row is entitled “Condensing boilers in existing dwellings”. The “SEDBUK 2009” and “SEDBUK 2005/SEDBUK” columns have been left blank. Under the “ErP” column, 92 per cent has been added.
• The first column in Table 1, which in previous versions was entitled “Condensing boilers” is entitled “Condensing boilers in new dwellings” in the 2018 version.

Section 2.2: Gas-fired wet central heating systems
The subtitle “Existing systems” has been replaced with “Work in existing buildings”

Components installed as replacements in existing systems should meet the same standards as for new systems, except where indicated otherwise in Table 4.

Where a new or replacement gas-fired boiler is installed in an existing dwelling, the following minimum standards should be met:

  • Boiler efficiency, in Table 2
  • Boiler interlock, time and temperature control.

If the new or replacement gas-fired boiler is a combination boiler, the following standard should be met:

  • • At least one of the energy efficiency measures in the “Minimum standard” column of section 2.0 of Table 4.

Table 4 lists the minimum standards when replacing components of gas-fired wet central heating systems. Table 4 in addition identifies good practice upgrades to the rest of the system (beyond the requirements of the Building Regulations) when making planned and emergency replacements.

Table 2: Recommended minimum standards for efficiency, system circulation, hot water storage, system preparation and commissioning for gas-fired wet central heating systems
The boiler ErP efficiency for boilers installed in existing dwellings should not be less than 92 per cent.

The “Minimum standard” column of row “1.0 Efficiency” of Table 2 states: “In existing dwellings, in the exceptional circumstances defined in the DCLG Guide to the condensing boiler installation assessment procedure for dwellings(2), the ErP efficiency standard would not apply and instead the SEDBUK 2009 efficiency should not be less than 78 per cent gas-fired, or not less than 80 per cent if LPG-fired.”

All boiler manufacturers should be calculating and declaring the energy efficiency of boilers in line with the Energy-related Products (ErP) methodology. For boilers in existing buildings, the ErP efficiency should be used and not the SEDBUK efficiency values.

Table 3: Recommended minimum controls for new gas-fired wet central heating systems
The standards in this table apply to new gas-fired wet central heating systems. In existing dwellings, Table 4 will apply.

Table 4: Recommended minimum standards when replacing components of gas-fired wet central heating systems
The recommended minimum standards when replacing components on all boiler types, except heating boilers that are combined with range cookers, are:

  • The ErP seasonal efficiency of the boiler should be a minimum of 92 per cent and not significantly less than the efficiency of the appliance being replaced – as set out in Section 1.8.
  • In the exceptional circumstances defined in the Guide to the condensing boiler installation assessment procedure for dwellings(2), the boiler SEDBUK 2009 efficiency should not be less than 78 per cent if natural gas-fired, or not less than 80 per cent if LPG-fired. In these circumstances, the additional requirements for combination boilers would not apply
  • Install a boiler interlock as defined for new systems.
  • Time and temperature should be installed for the heating system.

For a combination boiler, in addition to the above, at least one of the following energy efficiency measures should be installed. The measure(s) chosen should be appropriate to the system in which it is installed:

  • Flue gas heat recovery – defined as a device which pre-heats the domestic hot water supply by recovering heat from the boiler flue emissions
  • Weather compensation – defined as a device which pre-heats the domestic hot water supply by varying the flow temperature from the heat generator relative to the measured outside air temperature
  • Load compensation – defined as a control function that maintains internal temperatures by varying the flow temperature from the heat generator relative to the measured response of the heating system
  • Smart thermostat with automation and optimisation – automation is a function that automatically adjusts time and temperature settings, based on occupancy detection and/or stored data from user adjustments over time. Optimisation is a control function that starts the boiler operation at the optimum time to achieve the setpoint temperature at the start of the occupancy period.

Summary
This Industry Standard Update is a brief overview of the changes introduced by the publication of the revised versions of these documents. Registered businesses should be aware that they have a responsibility to ensure that they are fully apprised of all of the requirements of the practical application of these documents.

Bibliography
(1) Domestic Building Services Compliance Guide 2013 – England
(2) DCLG Guide to the condensing boiler installation assessment procedure for dwellings

Download Industry Standard Update 078 here.