Energy Performance of Buildings Directiveand energy certificates

Dr Paul DavidsonDirector, Sustainable Energy

BRE

Contents

• The EU EPBD• UK implementation

– Minimum standards – Part L

– Calculation methods

– Energy certificates

• Implications for local authorities

EU Energy Performance of Buildings Directive

• Directive 2002/91/EC of the European Parliament and Council published 4 January 2003

• Over 160 million buildings in Europe account for over 40% of CO2 emissions

• ‘Cost effective saving potential of 22% of current consumption by 2010’

• Aims to reduce CO2 emissions by 45 mt p.a. by 2010

Energy Performance of Buildings Directive(EPBD)

Requires Member States to introduce by end 2005 plans for:

Minimum Energy Performance Standards− an acceptable methodology for calculating the integrated energy

performance of buildings− minimum energy performance standards for new buildings− minimum energy performance requirements for large

existing buildings subject to major renovation Energy performance certificates

− provided to prospective purchaser/tenant− prominent display of the energy certificate in all public

buildings and “institutions providing public services” Regular inspection associated with

− boilers− air-conditioning systems

Directive Implementation Advisory Group (DIAG) supporting implementation

• Group of 22 professional institutions and umbrella trade associations (BRE Secretariat)

• Objective is to work with Government to ensure practical effective and timely implementation

− avoiding the problems caused by some other EU Directives

To download a copy of the EPBD

and other information, visit

www.diag.org.uk

Article 1 - Objective

• To promote the improvement of the energy performance of buildings within the Community,

• Taking into account– outdoor climatic and local conditions– indoor climate requirements – cost-effectiveness

Article 3 - National Calculation Methodology

• Adopt a national calculation methodology (Annex)• Must be transparent

• May include CO2 emission indicator

• Must be reviewed regularly (Article 13) by committee (Article 14).

• Implement through UK Building Regulations – Dwellings: SAP

– Other buildings: Simplified Building Energy Model (SBEM) for most situations.

– Commercial software to take on more complex buildings.

Annex

General framework for calculation of energy performance• Envelope, including airtightness• Heating and hot water services• Air-conditioning• Ventilation• Lighting• Outdoor climate• Solar gains and protection• Indoor climate• Renewables, chp and daylighting• Doesn’t specifically mention controls – but vital

Article 4 - Energy performance requirements

• Need to set legal minimum energy performance standards• Based on national methodology• Differentiate between new and existing buildings• Take indoor climate conditions into account (eg ventilation)• Review at regular intervals not exceeding 5 years• Some buildings may be exempt (eg historic buildings)• Implement through Building Regulations

Article 5 - New buildings

• Need to enforce legal minimum energy performance requirements. (i.e. prescription not guidance)

• For buildings over 1000m2, before construction, consider technical, environmental and economic feasibility of low and zero carbon energy supply systems:– Renewable energy systems– CHP– District heating or cooling

• Implement through Building Regulations

Article 6 - Existing buildings

• For buildings over 1000m2, when undergoing renovation, upgrade energy performance

• Technically, functionally and economically feasible• Renovated systems / components or building as a whole• Implement through Building Regulations

Article 7 - Energy Performance Certificates

7.1 Supply Energy Performance certificates 10 years old when buildings are constructed, sold or rented out.

7.2 Must include benchmarks and recommendations for improvement

7.3 Buildings >1000 m2 occupied by public organisations and visited by large numbers of the public must display certificate prominently.

• New build - Building Regulations Part L• Recent government statement on principles

– Calculated Asset rating for Article 7.1– Measured Operational rating for Article 7.3– Intend to widen display requirement to all public and private buildings –

following further consultation

Article 8 - Inspection of boilers

• Option (a) regular inspections -– 20kW to 100kW - inspection required for oil, coal etc. Member

States to decide for other fuels. – > 100 kW to be inspected every 2 years (4 years for gas).– One off inspection of heating systems with boilers over 20 kW and

over 15 years old.

• Option (b) provision of advice to users. • Possible implementation through a mix of (a) and (b)• See 2004 ODPM consultation report

Article 9 - Inspection of air conditioning systems

• Regular inspection of systems with rated output > 12 kW• Inspections must include:

– Assessment of efficiency and sizing– Advice on possible improvement or replacement.

• Possible implementation routes:– Put the requirement into Building Regulations using powers under the

Sustainable & Secure Buildings Act 2004.

– Refer to the proposed new CIBSE TM as approved guidance.

• Expert panel of CIBSE and FETA members has made proposals.

Article 10 - Certification and inspection

• To be “carried out in an independent manner by qualified and / or accredited experts … …”.

• So new qualification systems required for building energy surveyors and plant inspectors.

• Industry has reported with recommendations – keen to have Government approval schemes.

• See DIAG website www.diag.org.uk• Home Inspector qualification covers home energy rating• New Competent Person scheme for non-dwellings

– See www.bre.co.uk/energyrating

Article 15 - Transposition

• All laws, regulations and administrative provisions in place by 4 January 2006

• Additional 3 years for Articles 7, 8 and 9 if lack of qualified and / or accredited experts

Other policy drivers Energy White Paper (2003) Sustainable Development Strategy (2005)

Energy White Paper

• 3.12 - Raise standards over the next decade learning lessons from the standards in other European countries.

• 3.13 - Raise the standard required for new and replacement boilers to SEDBUK classes A or B.

• 3.15 - ODPM to take lead in implementation of the Energy Performance of Buildings Directive

• 3.16 - Start immediately on the next major revision of Building Regulations - aim to bring into effect in 2005.

Building Regulations Part L (E&W) – aims of the review

• To see what further contribution the Regulations can make towards achieving the Government’s carbon emissions targets whilst:-– Remaining proportionate– Continuing to provide satisfactory design flexibility– Avoiding unacceptable technical risks.

• To implement EPBD Articles 3,4,5 & 6

Principal changes to Part L

• Moves to a whole building approach based on energy/carbon targets

• Aims to reduce energy requirements by around 25%– implies significant improvements in insulation and heating system

efficiency– provides incentive for low and zero carbon technologies, especially with

fuels other than gas

• Extends coverage of measures installed in existing buildings

• Implements EPBD articles• Simplified ADs rely on second tier documents

Structure of Part L

• ADL1A – new dwellings• ADL1B – work in existing dwellings

• ADL2A – new buildings that are not dwellings• ADL2B – work in existing buildings that are not

dwellings

Part L – The Requirement

Part L Conservation of fuel and power

L1. Reasonable provision shall be made for the conservation of fuel and power in buildings by:

a) limiting heat gains and losses:

i. through thermal elements and other parts of the building fabric; and

ii. From pipes ducts and vessels used for space heating, space cooling and hot water services;

b. providing and commissioning energy efficient fixed building services with effective controls; and

c. providing to the owner sufficient information about the building, the fixed building services and their maintenance requirements so that the building can be operated in such a manner as to use no more fuel and power than is reasonable in the circumstances.

Regulation 17 – EPBD Article 3, 4 & 5 (ADL2A)

17A. The Secretary of State shall approve a methodology of calculation of the energy performance of buildings.

17B. The Secretary of State shall approve minimum energy performance requirements for new buildings, in the form of target CO2 emission rates, which shall be based upon the methodology pursuant to regulation 17A.

17C. Where a building is erected, it shall not exceed the target CO2 emission rate for the building pursuant to regulation 17B.

17E. In this Part ‘building’ means the building as a whole or parts of it that have been designed or altered to be used separately.

Regulation 17 – EPBD Article 6 (ADL2B)

17D. (1) Paragraph (2) applies to an existing building with a total useful floor area over 1000m2 where the proposed building work consists of or includes:

a. an extension

b. the initial provision of any fixed building services; or

c. an increase to the installed capacity of any fixed building services

(2) Subject to paragraph (3), where this regulation applies, such work, if any, shall be carried out as is necessary to ensure that the building complies with the requirements of Part L of Schedule 1.

(3) Nothing in paragraph (2) requires work to be carried out if it is not technically, functionally and economically feasible.

The compliance route for new buildings - ADL2A

• Meet the carbon target– Based on a whole building energy calculation

• Meet the worst acceptable standards– Envelope insulation

– Air permeability

– Efficiency of building services

• Control of summer overheating• Quality of construction & commissioning• Provision of information

Carbon emissions

1. Calculate carbon emissions from ‘notional’ building– 2002 elemental standards

2. Calculate carbon emissions target (TER)– Improvement factor + renewables benchmark

3. Calculate predicted carbon emissions from actual building (BER)– Same occupancy as notional building

• Preliminary calculation of BER at design stage• Final calculation of BER as built• BER must be lower than TER

Building certification – EPBD Article 7

• Asset rating• Operational rating• Implementation now decided in principle• Three year extension to train experts• Develop certification schemes• Home inspectors to prepare information for home

information packs

Why energy label a building?

• To demonstrate and quantify energy performance

• To show compliance with Building Regulations and EPBD

• To differentiate between buildings on basis of energy use

• To simplify specification for a new building

• To simplify requirements for leasing a building

• To drive up energy standards through market pressure

– to remove poorest performers

– to encourage competition for better performance

Energy labels for buildings

• Almost all relate only to components

• Some have a performance threshold

– pass criteria raised from time to time, but once given, label

remains

• Others place absolute performance on a relative

scale

Energy rating definitions

• New Building Design Rating– a calculation of building energy performance carried out as part of building

control submission

– used to show compliance with Part L energy performance requirements

• New Building Asset Rating – a calculation of intrinsic energy performance “as-built”

– rating base line to be the equivalent ‘notional building’

• Existing Building Asset Rating – provided to prospective purchaser or tenant

– based on the intrinsic energy performance of the building

• Operational Rating– used for public display/disclosure purposes

– based on actual building performance/energy management

– derived from metered energy data and floor area

What methods will be used to derive energy performance ratings in the UK?

• New Dwellings− dwelling carbon emissions rate calculated using SAP

2005• Existing Dwellings

− assessment using reduced data-set SAP (RD-SAP)− EPBD compliant Energy Report included in Home

Condition Report• New Non-Dwellings

− CEN based National Calculation Method for simple buildings (SBEM)

− simulation tools for complex buildings• Existing Non-Dwellings

− assessment using SBEM plus inference engine− Operational rating for public display

Energy ratings for dwellings

• SAP is the Government's Standard Assessment Procedure for Energy Rating of Dwellings.

• SAP 2005 is part of the UK national methodology for calculation of the energy performance of buildings.

• It is used– to demonstrate compliance for dwellings with Part L of the

Building Regulations (England and Wales) and– to provide energy ratings for dwellings.

• SAP is developed and maintained by BRE

SAP

• Calculation can be carried out via ‘manual’ worksheet + tables• Or by approved software

• Rating is based on net annual energy costs for– Space and water heating– Ventilation– Lighting

• Scale is from 1 to 100 (100 = zero energy cost)• Also calculates Dwelling CO2 Emission Rate (DER) (kg/m2/yr)• And Environmental Impact Rating (CO2) – 1 to 100• Independent of

– Household size– Ownership of electrical appliances– Individual heating patterns and temperatures

Reduced Data SAP for existing dwellings

• Based on site survey

• Limited collection of data

• Default U-values based on age and type of construction

• Provides recommendations for improvements

Part of Home Condition Report

Information for householders

Buildings other than dwellings Operational Ratings

• Based on measured in-use consumption data

• Includes intrinsic performance, plus effect of:

− Actual plant performance

− Actual occupancy, location, etc

− Actual management practices by occupants at the time

• A comparative rating with respect to benchmarks

• Used to establish scope for improvement

• Must recommend improvement measures

• No theoretical calculation required

Buildings other than dwellings

Calculation methods

• Either use simulation software (such as IES and TAS)• Or a new, simplified calculation tool – SBEM

• SBEM (Simplified Building Energy Model) was developed by BRE for ODPM in 2005

• Now the default calculation method for energy performance evaluation

SBEM – meeting two inter-related requirements

• Building Regulations Part L2a– New revision came into force April 2006

– New buildings – design approval and completion

• Energy Performance of Buildings Directive– Minimum energy performance for new buildings (Part L2A)

– Energy certificate required when sold or leased

– Energy certificate required for public display?

SBEM produces an Asset Rating• The calculated intrinsic performance of the building as built

• Normalised to standard conditions (weather, occupancy)

• Recognises different ‘activity areas’

• Applicable to both new and existing buildings

• Automatically compares with a ‘Notional Building’ as the baseline

• Used to demonstrate compliance with minimum standard

• And perhaps to generate a comparative rating (‘A-G’ or 0-100)

• Used to compare one building with others

• Also need a ‘Design rating’ before building is built

• Government has not yet finalised Asset Rating definition

Activity areas – distinct areas with distinct impacts on energy use

Will include, for example:

• Cellular office• Open-plan office• Sales area - ambient• Lecture theatre• Sports hall• Classroom• Storage - chilled• Toilets• Stairs

Activity schedules – to include

• Occupancy density

• Occupancy schedule

• Design temperature set-points

• Design ventilation rate

• Target illuminance

• Equipment gains

• DHW requirement

• Humidification if essential

• Standard values for Asset Rating

• (Tailored values for Tailored rating could be possible)

The rating and compliance test - NCM

CalculationTool

Inputdata

StandardActivity

Schedule

ActualCO2/m2/yr

ActualFabric & plant

Buildinggeometry

The rating and compliance test - NCM

Notionalbaseline

2002 Elemental standards

Fabric & plant

CalculationTool

Inputdata

StandardActivity

Schedule

ActualCO2/m2/yr

ActualFabric & plant

Buildinggeometry

National Calculation Method – overview of iSBEM approach

UserInterfaceiSBEM

Calculation coreSBEM

Interface

Activity Database

Fabricdatabase Service

database

Describing the building - key stages

• Geometry– Overall building layout– Distribution of activity areas

• Construction• Systems • Controls

• Two different input routes:– New build – from plans– Existing buildings – from brief survey and, eg, log book data,

supplemented by inference

iSBEM – General information

Calculating the Asset Rating

Summary of current tools

• Energy rating tool for housing – SAP• Energy rating tool for other buildings – SBEM• So far, used to demonstrate compliance with mandatory

Building Regulation standards• SAP is also used as an energy label• SBEM probably will be soon• BREEAM and EcoHomes provide ratings covering energy

along with other environmental issues

• SBEM is available at www.ncm.bre.co.uk• SAP at www.bre.co.uk/SAP2005 • BREEAM at www.breeam.org

Benefits of energy labelling

• Significant new drivers for building clients, owners and

developers:

− Brand image / Corporate Social Responsibility

− Environmental reporting associated with property portfolios

− Impact on asset value (positive and negative)

− An aid to procurement

• Introduces new requirement into the property transaction

process

• Fully glazed facades might be limited to prestige buildings

• Energy labelling should make architectural ‘greenwash’ more

difficult

Bill Bordass/Europrosper

Implications for local authorities

Immediate:• (Building Control responsibilities)• Generate energy labels for new buildings and large

extensions when designed and built

Soon• Operational ratings for large buildings with public access• Asset ratings for any buildings to be sold or let• Benchmarking of stock• Use of rating in procuring new buildings