OCTES Workshop

HIE Cowen House

1st November 2012

Building Standards and Energy Conservation

Building (Scotland) Regulations 2004

The above Regulations came into force 1st May 2005.

• Section 0 – General• Section 1 - Structure• Section 2 – Fire• Section 3 – Environment• Section 4 – Safety• Section 5 – Sound Insulation• Section 6 – Energy• Section 7 – Sustainability

The Standards can be downloaded from the Scottish Governments Website www.scotland.gov.uk/Topics/Built-Environment/Building

Why do we need energy standards

• As a member of the EU the UK is required to comply with the Energy Performance Directive.

• The implementation of the Directive in Scotland has been taken forward primarily through the Building Standards Legislation and the Energy Performance of Buildings (Scotland) Regulations 2008.

The Key features of the EPD, which are enforced by the Building Regulations are;

• The establishment of methodologies for calculating the integrated performance of buildings (energy efficiency and carbon emissions) i.e. SAP 2009.

• The application of minimum energy standards.

• That all new buildings be provided with an Energy Performance Certificate.

• The display of an EPC in large public buildings, over 1000m² in floor area.

• Regular inspections of heating and air conditioning systems.

• In 2007, the Sullivan Report set out a Low Carbon Building Standards Strategy for Scotland. A key recommendation of this report is staged improvements in energy standards in 2010 and 2013, with the aim of net zero carbon buildings in 2016.

• The Scottish Government is committed to achieving carbon reduction through the sustained improvement of the national regulations

• The energy standards which came into force in October 2010 were designed to deliver a 30% reduction in dwelling carbon emissions from the 2007 standards and a 70% reduction in carbon emissions compared to the 1990 standards.

• It is proposed the next changes to the standards will achieve a reduction of 80% compared to the 1990 standards.

• When will the next review of the energy standards take place?

Key Summary of the Changes implemented in October 2010

• Revisions to the SAP calculation methodology (SAP 2009) to deliver 30% aggregate improvement on target emissions by;

amended fuel package table, revising fabric values and control specification; application of Low Carbon Equipment (LCE) components, specification of reduced infiltration rate and increase in low energy lighting, alternative approach for solid mineral fuel.

• Improved fabric backstops (U-values) for newbuild, proposal to address performance of cavity separating walls.

• Revised guidance on limiting non-repeating thermal bridging & revision of current Accredited Construction Details document.

• Expanded guidance on limiting uncontrolled air infiltration, including reference to standard 3.14 where very low infiltration rates proposed.

• Introduction of airtightness testing regime. • Improved U-values for conversion of heated buildings (aligned with non-domestic

proposals).

• Expanded guidance on how to address energy performance in conversion of older buildings.

• Improved fabric backstops for extensions; alternative approach for highly-glazed

extensions. • Standard 6.5 - standard extended to include lighting in common areas of domestic buildings. • Standard 6.5.1 - increase percentage of energy efficient lighting; revised minimum efficacy; addition of guidance on lighting in common areas. • Clause 6.5.2 - new guidance clause on efficiency of external lighting.

• Standard 6.6 - standard extended to include ventilation and cooling systems in domestic buildings. • Clause 6.6.2 - new guidance clause on efficiency of air conditioning systems. • Clause 6.6.3 - new guidance clause on efficiency of mechanical ventilation systems.

• Standard 6.8 - standard extended to cover ventilation and cooling systems in domestic buildings.

• Standard 3.14 (ventilation) - revision of guidance under clauses 3.14.2 (Ventilation of dwellings) & 3.14.10 (Mechanical aids to ventilation) to recognise trend towards building tighter to limit infiltration. • Amended introduction to BSD Accredited Construction Details Document.

There are approximately 85 mandatory standards which are supported by technical guidance on how to comply with these standards. The technical guidance is not prescriptive and it is possible to use alternative methods to achieve compliance. The standards and guidance are published in two technical handbooks for domestic and non-domestic buildings.

The guidance in the technical handbooks is reviewed regularly to keep up with policy changes, to meet statutory requirements, technical advancements etc.

Since 2005 there have been 6 revisions of the technical handbooks and the BSD is currently considering the next set of amendments.

Section 6, Energy, is reviewed every three years with the last major change coming into force in October 2010.

Mandatory Standard 6.1

Every building must be designed and constructed in such a way that:

(a) the energy performance is estimated in accordance with amethodology of calculation approved under regulation 7(a) ofthe Energy Performance of Buildings (Scotland) Regulations2008; and

(b) the energy performance of the building is capable of reducingcarbon dioxide emissions.

SAP 2009 software is the current methodology, approved by the BRE for the Scottish Regulations, used to establish the carbon emission ratings of a dwelling.

SAP 2009 calculates two carbon emission ratings for the proposed dwelling. The first is based on the dwelling wall, floor areas etc. but uses a standard package and this is called the target rating (TER). The second uses the actual construction, heating, ventilation specifications for the dwelling and is called the dwelling rating (DER). The DER should be less than the TER. The TER allows flexibility in the design as different elements can be traded off against each other

While the thermal properties of the dwelling help reduce the SAP rating, by far the biggest impact is the inclusion of Low Carbon Equipment such as solar panels to heat water and produce electricity along with heat recovery systems

Mandatory Standard 6.2

Every building must be designed and constructed in such a way that an insulation envelope is provided which reduces heat loss.

The main changes to this section implemented in 2010 are;

• Improvement of u-values to achieve a 30% improvement on the 2007 standards.

• Accredited construction details.

• Air tightness testing

U-Values W/m²K. 2007 2010

Walls 0.30 0.25

Floors 0.25 0.20

Ceilings 0.2 0.18

Doors/windows 2.2 1.8

U-Value table for New Build Domestic

Extension Domestic

U-Value W/m²K 2007 2010

Wall 0.27 0.19/0.22

Floor 0.22 0.15/0.18

Ceiling 0.16/0.20 0.13/0.15

Doors/Windows 1.8 1.4/1.6

6.2.4 Limiting uncontrolled air infiltration

To limit heat loss, any heated building should be designed to limit uncontrolled air infiltration through the building fabric.

Accredited Construction Details (Scotland) 2010 have been produced by the BSD and are available to view on their website. While these details are deemed to limit air infiltration, air tightness testing will be required to establish the actual infiltration rate.

Important notes

Limiting air infiltration to improve energy performance should not compromiseventilation required for:

• the health of the occupants of the building (section 3);• the removal of moisture from building fabric (section 3);• the safe operation of combustion appliances (section 3); and• any smoke control system (section 2).

Lower air infiltration rates, of less that 5 m³/m².h @ 50 Pa, may give rise toproblems with internal air quality and condensation. Therefore the guidance on enhanced ventilation systems such as whole house ventilation systems with heat recovery should be considered at the design stage.

Examples of Accredited Construction Details

6.2.5 Air-tightness testing

Low air infiltration rates will contribute to energy performance but should notbe so low as to adversely affect the health of occupants or the building fabric.There is, therefore, a need to establish building performance by test, todemonstrate compliance in both these respects.

Air-tightness testing should be carried out on new buildings to ensure that air infiltration rates deliver both the stated design level under this guidance and minimum levels of ventilation needed.

To allow the capacity for air testing to grow the requirement was therefore phased.• Flats and maisonettes after 1st May 2011, and• Houses after 1st October 2011.

Where a default value of 15 m³/m².h @ 50 Pa is stated in demonstrating compliance under standard 6.1, testing need not be carried out.

Standard 6.9, Every building must be designed and constructed in such a way that:

(a) an energy performance certificate for the building is affixedto the building; and

(c) the energy performance certificate is displayed in aprominent place within the building.

Article 7 of EU Directive (2002/91/EC) on the energy performance of buildingsrequires energy performance certificates (EPCs) to be made available to prospective owners and tenants when dwellings are constructed.

Standard 6.9 achieves this by making EPCs fixtures within buildings.

The EPC is produced by the same methodology and software used to calculate the SAP rating.

Mandatory Standard 7.1

Every building must be designed and constructed in such a way that—

(a) with regard to a dwelling, a level of sustainability specified by the Scottish Ministers in respect of carbon dioxide emissions, resource use, building flexibility, adaptability and occupant well-being is achieved;

(b) with regard to a non-domestic building, a level of sustainability specified by the Scottish Ministers in respect of carbon dioxide emissions is achieved; and

(c) a statement of the level of sustainability achieved is affixed to the dwelling or non-domestic building.

The specified level of sustainability for a dwelling should be selected from thefollowing:

• Bronze or Bronze Active• Silver or Silver Active• Gold

There is also a Platinum level .

The statement of sustainability certification, unlike SAP or EPC’s which focus onCarbon emissions, takes all aspect of the building and its construction into account. There is no mandatory level at the moment. Any dwelling constructed in accordance with sections 1-6 of the 2010 standards will achieve Bronze Level and Bronze Active Level if low and zero carbon generating technology (LZCGT) is used, which would normally be the case to achieve the target carbon emissions rating.