The Road to Zero Carbon

Andrew Mitchell Director, BBS Environmental

History of Road Map to Zero Carbon

• 2006 - Labour Government introduced revision to Part L

• At the same time Zero Carbon roadmap defined

• By 2016 all new dwellings will be ZERO CARBON

• Part L & SAP (Standard Assessment Procedure) tools to measure Zero Carbon

• July 2010 - current Government confirm commitment to Zero Carbon dwellings

Time Line to Zero Carbon

• Part L 2006 defined B Regs compliance via CO2 targets

• 2010 - CO2 target increase by 25%

• 2013 - CO2 target increase by 44%

• 2016 - All new dwellings to be ZERO CARBON

Definition of Zero Carbon

• Part L 2006 defined Zero Carbon to include regulated & unregulated emissions

• Regulated – Emissions from space & water heating and fixed lighting (include within B Regulations)

• Unregulated – Emissions from cooking & plug in equipment (TV, white goods, Play Station etc.)

Regulated or Un-Regulated

• Unregulated emissions contributes approx 40% to 50% of total CO2 emissions

• March 2011 - Government redefined Zero Carbon to only include regulated emissions

Factors to Deliver Zero Carbon

• High performance thermal envelope – U values, thermal bridging, air tightness and orientation

• Efficient equipment – Boiler (fuel type important), controls, ventilation and lighting

• Renewables– Photovoltaic panels, solar thermal, heat pumps, etc. (have to generate electricity)

How CO2 Emissions are Calculated Within SAP

• All emissions are a function of calculated energy consumption multiplied by the fuel carbon factor

• Space heating – function of thermal envelope performance, boiler efficiency & controls

• Water heating – function of floor area

• Lighting – function of floor area

AREA U

VALUE

Ground Floor 0.16

External Wall 0.20

Roof 0.09

Party Wall 0

Windows 1.4

Doors 1.0

U VALUES

Thermal Mass: Medium

Air Permeability: 5

Thermal Bridging to ACD

HEATING & HOT WATER

Gas fired condensing boiler min SEDBUK 89% Cylinder 150 litres

Radiators Time and temperature zone control & load

compensator

VENTILATION & LIGHTING

Extractor fans (X3) 100% LEL

TFATFA

DER 20.38kgCO₂/m²/yr

TER 20.38kgCO₂/m²/yr

TFA of house 60m² Semi-detached

East/West orientation

SAP2009 compliance

The BBS House

1

AREA U

VALUE

Ground Floor 0.16

External Wall 0.20

Roof 0.09

Party Wall 0

Windows 1.4

Doors 1.0

U VALUES

Thermal Mass: Medium

Air Permeability: 5

Thermal Bridging to ACD

HEATING & HOT WATER

Gas fired condensing boiler min SEDBUK 89% Cylinder 150 litres

Radiators Time and temperature zone control & load

compensator

VENTILATION & LIGHTING

Extractor fans (X3) 100% LEL

TFATFA

DER 16.30kgCO₂/m²/yr

TER 20.38kgCO₂/m²/yr

TFA of house 60m² Semi-detached

East/West orientation

PV =

0.55kWpeak 4.4m2

SAP2012 compliance

The BBS House

2

AREA U

VALUE

Ground Floor 0.16

External Wall 0.20

Roof 0.09

Party Wall 0

Windows 1.4

Doors 1.0

U VALUES

Thermal Mass: Medium

Air Permeability: 5

Thermal Bridging to ACD

HEATING & HOT WATER

Gas fired condensing boiler min SEDBUK 89% Cylinder 150 litres

Radiators Time and temperature zone control & load

compensator

VENTILATION & LIGHTING

Extractor fans (X3) 100% LEL

TFATFA

DER 0kgCO₂/m²/yr

TER 20.38kgCO₂/m²/yr

TFA of house 60m² Semi-detached

East/West orientation

SAP 100% Improvement

PV = 2.8kWpeak

20m2

Zero Carbon 2016

The BBS House

Floor Area to PV area ratio

3 : 1 3

Changes to Part L 2013

• Dwelling emissions target with new Fabric Energy Efficiency Standards (FEES)

• FEES target to ensure ‘renewables’, or low carbon technologies, are not introduced to compensate for thermally inefficient building fabric

• FEES will be measured in kWh/m2/year

• FEES target will vary for dwelling type – detached, mid terrace, flats etc.

Changes to Part L 2013

• Consultation document indicates discrepancy between calculated & as built dwelling performance

• As a result, confidence factors to be included with SAP results

• If a prescribed quality assurance scheme is not followed during design & build, 3% is added to the results

Technologies to Improve SAP Results

Fabric improvements:

• Thin joint internal blockwork

• Triple glazed windows (U values below 1.0)

• Full fill PIR – Xtratherm

• SIP systems

Technologies to Improve SAP Results

Low Carbon Technologies:

• Gas or liquid Biomass CHP - district heating system

• Biomass boilers

• MVHR ventilation systems

• Boiler flue & waste water heat recovery systems

• Ground or air source heat pumps

• Fuel cells

Zero Carbon 2016 – ‘Allowable Solutions’

• Studies have confirmed that not all dwelling types will be able to achieve Zero Carbon – can not fit the required PV on the roof !!!

• Proposal is that ‘Carbon Compliance’ target is met on site via fabric & renewables (targets currently being debated)

• Then ‘allowable solutions’ will mitigate the remaining CO2 emissions

What are Allowable Solutions?

• Local Planning Authority to have prescribed allowable solutions

• Or the developer pays into a private energy fund

• Both of the above will have associated verification & certification procedures that will need to be approved by Building Control

Ashford Carbon Fund

• One-off contribution into Ashford Carbon Fund

• Current charge £28.50 per tonne of CO2. Increases by 2% per annum over 10 years

• Dwellings built to Part L 2010 - this represents a cost of approx. £600 per dwelling

References

• Carbon Compliance: Setting limits for Zero Carbon – Zero Carbon Hub

• Defining A Fabric Energy Efficiency for Zero Carbon Homes – Zero Carbon Hub

• Allowable Solutions for tomorrows New Homes – Zero Carbon Hub

• SAP 2012 in a Nutshell – National Energy Services

Any Questions