Topic 3
Understanding the
Energy Requirements
Planning for Climate Change - Delivering Sustainable Buildings & Quality Design
Learning Objectives
By the end of this session, you should have a basic
understanding of:
• Terminology used in relation to energy requirements
−
e.g Ene 1, TER, DER, BER, Part L, regulated CO2, SAP,
EPC
• Regulated and unregulated energy use and CO2 emissions
• What a SAP assessment is and how it is related to the policy
requirement for dwellings
• What a non-domestic EPC is, and how it is calculated
• What Low and Zero Carbon energy technologies are
• How the Code energy targets can be met
Regulated vs. Unregulated Energy
Regulated Energy Use
• Partly related to quality of building
• Regulated by Part L
• Covered by Code Levels 1-5 for
dwellings
Unregulated Energy Use
• Related mainly to occupants
• Not (currently) regulated by Part L
• Covered by Code Level 6 for dwellings
Cooking 9%
Appliances
28%
Communal Lighting 5%
Mainly IT use
Converting Energy to
Energy is consumed by buildings & CO2 is emitted
– either at the building or at the source of the energy
CO2 conversion factors are used to convert each unit of energy consumed
by a building into CO2
Grid
Electricity
is twice as
carbon
intensive as
natural gas
0.42kg
CO2
0.19kg
CO2
1 kWh electricity
1 kWh gas
Assessing Regulated Emissions for Dwellings
•
•
•
•
•
•
SAP is Government’s Standard Assessment
Procedure for calculating regulated energy
performance of dwellings
Dwellings are modelled using approved software
by accredited SAP assessors to verify Part L1A
compliance
Part L of the Building Regulations relates to the
Conservation of Fuel and Power – L1A is for new
dwellings, L2A for new non-dwellings
The Target Emission Rate (TER) is the cap for
Part L1A compliance – kg CO2/m2 per annum
To pass Criterion 1 of Part L1A of the Building
Regulations the Dwelling Emissions Rate (DER)
must be less than or equal to the TER
Typical TER for new dwelling, on gas, is 2025kgCO2/m2 per year
Data entered into SAP model
• Building dimensions
• Heat loss walls, floors, roofs
• U-values
• Windows, doors, rooflights
• Ventilation
• Space and water heating
• Lighting
• LZC energy technologies
CSH Level
% better than
Part L 2006
1
10
2
18
3
25
4
44
5
100
6
Zero carbon
home*
* Includes unregulated carbon emissions
Regulated CO2 for Dwellings
The source of CO2 for a typical new dwelling:
Total Regulated CO2 (TER)
Ventilation losses 18.5%
Roof 2.0%
Thermal
bridging 10%
Space heating 51.5%
(made up of heat losses shown)
Walls 8.0%
Windows 8.5%
Door 1.9%
DHW use 30.5%
Lighting 15%
G floor 2.5%
Pumps and fans 3%
Low & Zero Carbon (LZC) Energy Sources
Why not just say “renewable energy”??
LZC Energy - Community Heating
Community heating is characterised by:
•
Heat and/ or electricity are produced by a central
energy centre
•
Heat is carried to building by ‘heat mains’ –
buried, insulated pipes
•
Reduced dependence UK centralised generation,
e.g. National grid and gas network
•
Can be powered by, e.g. gas CHP, biomass, waste
power station heat
•
Can be low carbon or renewable, depending on
fuel source
Low & Zero Carbon (LZC) Energy Sources
Low carbon energy technologies:
Heat pumps:
Combined heat and power (CHP)
Fuels :Gas, waste
Types: Engine, fuel cell, Advanced
Thermal Treatment
Scale:
Communal heating or per dwelling
Low & Zero Carbon (LZC) Energy Technologies
Zero carbon/renewable energy
Biomass heating
Wind power
Solar thermal/solar hot
water (SHW)
Solar photovoltaic (PV)
Fuels :Wood chip, logs or
pellets
Scale:
Communal heating or per
dwelling – can also be
CHP at large scale
SAP and the Code Requirements
There are some difference between SAP and the Code’s treatment
of energy and LZCs:
Code Ene 1
Part L1A
Photovoltaics
CO2 saving allowed for PV which
connects to landlords supply
CO2 savings only allowed if PV
connects to specific dwellings
Multiple
assessment
As for SAP 2005, apart from:
1,terraced houses cannot be averaged
2, the same services must be used in all
Allows multiple dwellings within a
building to be averaged in terms of
emissions.
Large wind
turbines +
Hydro
+Renewable
Fuel Cells
Ene 1 allows for CO2 savings from
large wind turbines and hydro
No approved way of allowing CO2
saving for Part L1A compliance
Full CO2 saving of biomass CHP can be
allowed for in calculation of Ene 1 score
DER for Part L1A cannot take full
advantage of CO2 savings from
Biomass CHP - to prevent poor
building fabric being used to lower DER
Biomass CHP
EPCs and Non-domestic Buildings
EPCs are required on all new buildings:
• shows building’s CO2 vs. CO2 of standard new
building of same size and occupancy with mixed
mode ventilation (standard building scores 50)
• required by the EU Energy Performance of
Buildings Directive EPBD
• enforced by Trading Standards
• an asset rating: linked to building quality, not
dependant on operation
• calculated by SBEM methodology, as used for
Part L2, based only on regulated energy use
• BREEAM Excellent requirement for rating of 40
requires CO2 emissions to be about 20% less
than typical new build
EPCs and Non-domestic Buildings
Not to be confused with:
EPCs and BREEAM Requirements
EPC Rating
•
•
•
BREEAM credit Ene 1 is determined
by the building’s EPC (for reduction
of CO2 Emissions)
BREEAM Credits
New Build
Refurbishment
1
63
100
2
53
87
3
47
74
BREEAM ‘excellent’ requires EPC
score of 40 (6 credits for Ene 1)
4
45
61
5
43
50
6
40
47
Linking to EPC means naturally
ventilated building are fairly treated
7
37
44
8
31
41
9
28
36
10
25
31
11
23
28
12
20
25
13
18
22
14
10
18
15
0
15
Exemplary level
credit 1
<0
≤0
Exemplary level
credit 2
True zero carbon building*
* Includes unregulated carbon emissions
Achieving Code Level CO2 savings
Typical CO2 reductions for LZCs and Energy Efficiency
For a typical 3 bed semi detached house
Part L
Compliant
Dwelling
Improvement on Part L TER in %
Code level 3 min standard
0
10
20
30
Code level 4 min standard
40
50
60
2016 Part onsite (estimated)
70
80
90
Code level 5 min standard
100
110
120
Code level 6 approx standard
130
140
150
160
Best Practice Energy Efficiency
Advanced Practice Energy Efficiency
Solar Hot Water+ BPEE
Solar Hot Water+ APEE
Plant sizes:
PV maximum saving + BPEE
Solar Hot Water: 4m2
PV maximum saving + APEE
PV for max saving = 2.54kWp, 20m2
Ground Source (2006‐2009) +BPEE
Ground source = 9kW unit
Ground Source(2006‐2009) +APEE
Gas CHP = communal system
Ground Source (2010+) +BPEE
Biomass heating + BPEE
Biomass heating + APEE
Gas CHP +BPEE
Air source (2006‐2009) + BPEE
Biomass Heating = communal system
LZC Energy Options – Implications for
Scheme Design