The Code for Sustainable Homes:
Towards Zero Carbon
Alan Yates
Technical Director, BREEAM
BRE Certification
Overview
•
Based on EcoHomes 2006
•
Linked to continuous improvement in
legislation, policy and good practice
•
Amended scope of assessment
•
Amended assessment criteria
•
Post construction certification
•
Only covers New build in England
Major differences
EcoHomes
The Code
Site Assessment
Individual Dwelling Assessment
(based on Dwelling Types)
Usually ‘design stage’ only
Assessed in 2 stages –
design stage and upon completion.
Flexible standards in all categories
Fixed Minimum Standards (thresholds) for
some categories
Absolute carbon levels
Energy based on percentage improvement
over Building Regulations
Includes locational credits related to
transport and amenities
Locational credits related to transport and
amenities omitted.
New points for ‘Lifetime Homes’
Regulatory minimum
Number of buildings
Minimal
Environmental Standards
CSH
Aspirational
Level 6
Level 5
Level 4
Level 3
Level 2
Level 1
Mass market
Code Issue Categories
•
Energy/CO2
•
Water
•
Materials
•
Surface Water Run-off
•
Waste
•
Pollution
•
Health & Well-being
•
Management
•
Ecology
•• Water
Water Surface
SurfaceRun
Run-off
-off
•• Energy
Energy
•• Potable
PotableWater
Water
Consumption
Consumption
•• Waste
Waste
•• Materials
Materials
•• Water
Water Surface
SurfaceRun
Run-off
-off
•• Pollution
Pollution
•• Health
Health && Wellbeing
Wellbeing
•• Management
Management
Environmental Weightings
•• Energy
Energy
•• Potable
PotableWater
Water
Consumption
Consumption
Issue Category Scores
Mandatory
Standards
Tradable Credits
•• Waste
Waste
•• Materials
Materials
Overall
Score
Level 1
Level 2
Level 3
Level 4
Level 5
Level 6
Weightings
Energy
Potable Water
Surface Water Runoff
Materials
Waste
Pollution
Health and Wellbeing
Management
Site Ecology
36.4 %
9%
2.2 %
7.2 %
6.4 %
2.8 %
14 %
10 %
12 %
Code levels and points score
Code Levels
Total Points Score out of 100 Approx equivalent
EcoHomes rating
(equal to or greater than):
Level 1 ()
36 Points
Pass (36%)
Level 2 ()
48 Points
Good (48%)
Level 3 ()
57 Points
Very Good (58%)
Level 4 ()
68 Points
Level 5 ()
84 Points
Level 6 ()
90 Points
Excellent (70%)
Minimum standards
Categories
Flexibility
Energy Efficiency
6 levels of minimum standards one for each level of the
Code
Water Efficiency
Three levels of minimum standards each covering two
levels of the Code
Materials
A single basic standard at Code entry level
Surface Water Run Off
Waste
Pollution
Health & Well-Being
Management
Ecology
No minimum standards
Minimum Energy Standards
Based on SAP:2005 calculation and % improvement on 2006 Building Regulations
Part LA
Code Level
Energy Performance
Equivalent standards
Level 1
10% improvement
EST Good
Level 2
18% improvement
Level 3
25% improvement
EST Best
Level 4
44% improvement
Approx. PassivHaus / EST advanced
Level 5
100% improvement
Level 6
Full Zero Carbon
Approx 145% improvement over
ADL1A: 2006
Minimum Carbon Dioxide Emissions
Standards
Building Regulations Part L1a: 2006
• Target Emission Rate (TER) –
minimum requirement
• Dwelling Emission Rate (DER) –
actual emissions
• 30% dedicated low energy lighting
provision
• Compliance with other aspects –
Fabric Backstop standards
Minimum Energy Standards
The Code requirements (as ADL:2006)
Levels 1-5
• The % improvement in the actual emissions over the
target emission for each Code Dwelling type.
• i.e. [1-(DER/TER)] *100%
• Accredited energy assessor/Part L ‘competent
person’- The term ‘SAP Assessor’ is to be replaced
• When a building contains more than one dwelling,
area-weighted average DER and TER for the building
as a whole is acceptable (as described in clause 23 of
Approved Document L1A).
Minimum Energy Standards
The Code requirements (as ADL:2006)
Level 6 – Where net Carbon Dioxide emissions
resulting from ALL energy use in the dwelling is
Zero.
• Must meet Level 5 threshold by on site means
• Heat Loss Parameter (HLP) of ≤0.8m3/hr/m2
• Appliances demand can be met
• by on site renewables/low carbon technologies
• OR by off site independently accredited renewables
• Some ESCOs comply where directly supplying
• Definition very similar to HM Treasure Stamp Duty
relief
Ene 1 – Dwelling Emission Rate
% improvement of DER over
TER
Credits
Mandatory Levels
≥ 10 %
1
1
≥ 14 %
2
≥ 18 %
3
≥ 22 %
4
≥ 25 %
5
≥ 31 %
6
≥ 37 %
7
≥ 44 %
8
≥ 52 %
9
≥ 60 %
10
≥ 69 %
11
≥ 79 %
12
≥ 89 %
13
≥ 100 %
14
5
True Zero Carbon
15
6 (ADL:2016)
2
3
(ADL:2010)
4
(ADL:2013)
Passiv Haus Standard – UK Standard
PassivHaus
UK Standard Practice
U Values
< 0.15 W/m2/K
0.25-0.35 W/m2/K
Energy Efficient Glazing
< 0.80 W/m2/K
50% heat gain coefficient
< 1.80-2.2 W/m2/K
Air tightness
< 1 m3/hr/m2 @ 50Pa
7-10 m3/hr/m2 @ 50Pa
Passive ventilation
preheating
Ground ducts and/or heat
recovery
None
Passive solar
Key design factor
Limited
Lighting
Low energy lighting
throughout
30% low energy lighting
required
TOTAL Energy
space heating
< 15 kWh/m2/yr
Typically 55 kWh/m2/yr
Minimum Carbon Dioxide Emissions
Standards
The following are not covered within
SAP at present but can be taken into
account:
• Cooling
• LZC technologies not covered by SAP
• Newer low energy technologies
• Lighting
• Appliance loads
Tradable Credits
Tradable credits awarded:
• for higher performance levels in some key issues
• for remaining issues
– Broadly as in EcoHomes 2006
– Location issues omitted
– Some additional credits
Tradable Credits - Energy
Ene 1 - Dwelling Emission Rate (DER)
 Additional credits available for achieving a
higher scale percentage improvement over
Building Regulations
 Credits based on % improvement above
Building Regulations part L1a instead of
actual CO2/m2/year as under EcoHomes 2006
Tradable Credits - Energy
Ene 2 - Building Fabric
• Credits awarded based on the Heat
Loss Parameter obtained from the SAP
calculations
• HLP ≤ 1.1 or 1.3
• Same as EcoHomes 2006
Tradable Credits - Energy
Ene 3 - Internal Lighting
• Credits awarded based on the % of dedicated
energy efficient light fittings
• 40% or 75% dedicated low energy light
fittings
• Same as EcoHomes 2006
Tradable Credits - Energy
Ene 5 - Energy Labelled White Goods
• Provision of specific EU Energy Efficiency
Labelled white goods or
• EU Energy Efficiency Labelling Scheme
purchasing information.
• Same requirement for social and private
housing
Tradable Credits - Energy
Ene 6 - External Lighting
• Credits awarded based on the
provision of dedicated energy efficient
light fittings
• Or security lighting with movement
detectors and daylight shut-off devices
• Same as EcoHomes 2006
Tradable Credits - Energy
Ene 7 - Zero/Low Carbon Technologies
• Credits for Zero/Low Carbon technologies
where they make a significant contribution to
the energy demands
• 1 credit: 10% carbon dioxide reduction
• 2 credits: 15% carbon dioxide reduction
• 2 instead of 3 credits
• Credits for feasibility study only dropped
• Off site generation may be accepted under
certain criteria
Tradable Credits – Other Categories
•
•
•
•
•
•
•
Potable water consumption
External water consumption
Daylighting
Drying Space
Home Office
Cycle Storage
Materials – embodied impacts including
CO2
• Home User Guide
• Building Footprint
Achieving Code Level 1
• Energy – 10% improvement over TER
• Meeting the Energy Requirements
–
–
–
–
Improved thermal efficiency of building fabric
Reduction in air permeability
High efficiency condensing boiler
Reduction of thermal bridging
• Other mandatory requirements
• Additional 33 optional points
Achieving Code Level 3
• Energy – 25% improvement over TER
• Meeting the Energy Requirements
– Measures outlined for Code Level 1
– Maximum benefit from cost effective ‘conventional’ solutions to fabric and
systems efficiency
– + possible use of low or zero carbon technologies in some cases
• Other mandatory requirements
• Additional 47 optional points
Achieving Code Level 4
• Energy – 44% improvement over TER
• Meeting the Energy Requirements
– High performance building fabric and efficient systems/controls
– + some use of low or zero carbon technologies
• Other mandatory requirements
• Additional 54 optional points
Achieving Code Level 5
• Energy – 100% improvement over TER
• Meeting the Energy Requirements
– High performance building fabric and efficient systems/controls
– + significant use of low or zero carbon technologies (individual dwelling or
community system).
– No off site renewables unless independently accredited and ‘additional’.
• Other mandatory requirements
• Additional 60 optional points
Achieving Code Level 6
• Energy – Approximately 145% improvement over TER
• Meeting the Energy Requirements
– Optimal performance building fabric and systems/controls
– use of low or zero carbon technologies (individual dwelling or community
system).
– Likely to include use of off site renewables but must be:
• independently accredited
• ‘additional’.
• Other mandatory requirements
• Additional 60 optional points
A Two-stage Process
• Design Stage
– Based on design drawings, specifications and
commitments
– Results in interim certificate of compliance
+
• Post Construction Review
– Based the design stage information
– Confirmation of compliance through site
records and visual inspection.
– Code certificate awarded based on compliance
at this stage.
BRE – Innovation Park Houses
Food for thought
• Achieving zero carbon is not easy but it is achievable
• We have limited experience to date but a lot of
knowledge to help
• Code presents a tool for measuring and evaluating
performance