HPM
INDUSTRY
WATCH
The Standard Assessment Procedure
(SAP) is the methodology used
by the government to assess
and compare the energy and
environmental performance of dwellings.
Following an extensive consultation
in November 2016, the government has
now published SAP 10, which will replace
the outdated SAP 2012 calculation that
has been in use since 2013. SAP 10 will
however, not take effect until Part L/
Section 6 of the Building Regulations is
updated.
COMPLIANCE IS KING
While it is easy to perceive SAP
calculations as another obstacle on the
road to a fi nished residential project,
they serve to work out a dwelling’s
carbon emission rate, produce an Energy
Performance Certifi cate (EPC) and to
demonstrate to Building Control that a
building complies with energy effi ciency
requirements. It is one part of a wider
strategy in the government’s bid to drive
down emissions and work towards a zerocarbon
nation.
REALISTIC PATTERNS
The Department for Business, Energy
& Industrial Strategy and Building
Research Establishment have adopted a
standardised heating pattern for central
heating within SAP 10, following the
extensive consultation which saw 43
respondents in favour of adopting two
comfort level periods.
The heating patterns to be adopted
are 07:00-09:00 and 16:00-23:00, which
means that SAP will refl ect the changes in
modern demands for heating as we are in
our homes less overall, and subsequently
will require less heating.
Properties to be built moving forward
can, therefore, expect better ratings owing
“Properties to be built moving forward
can expect better ratings owing to the
reduced demand for energy”
to the reduced demand for energy which
can be attributed to improvements in the
fabric of the building, condensing boilers
and wider use of heating controls.
EYES ON ELECTRIC
The changes that will be implemented
with the introduction of SAP 10 will
see the favourability of electric heating
increase. Arguably, the current SAP 2012
methodology takes an outdated approach
to electrical heating within residential
dwellings.
Since its introduction in 2012, there
has been a push for greener electricity
generation and lower grid carbon
emissions which has resulted in an increase
in the use of renewable technologies, such
as wind farms and solar, which link to the
energy effi ciency and carbon emissions
fi gures which SAP uses.
Currently SAP assumes 2.4 times the
amount of carbon is produced when using
electricity at building level as opposed to
gas, however, SAP 2012 uses an outdated
carbon factor which does not refl ect the
current energy mix of the grid.
As such, the reduction of electricity’s
annual average carbon dioxide (CO2)
emission factor from 0.519 kgCO2/kWh
to 0.233 kgCO2/kWh (a 55% reduction)
is an important change for the industry,
and places electricity just behind gas
which has a CO2 emission factor of 0.210
kgCO2/kWh.
The initial proposal for the
reduction of electricity’s
carbon factor was
0.398 kgCO2/kWh
– evidently SAP 10
has far surpassed
preliminary
recommendations
which sees the
government halve
the carbon factor of electricity.
A POSSIBLE IMPROVEMENT
FOR SAP?
The fi gures utilised by SAP 10 for carbon
emissions would more accurately refl ect
the seasonality of the heating season
from October through to March by being
calculated using monthly as opposed to
annual fi gures. This would mean that
the annual carbon emissions savings
associated with the green generation
of technologies will vary depending on
output.
For example, where solar panels
generate high outputs in the summer
months but decline steadily throughout
winter, the carbon emission factor
would better refl ect this. These monthly
fi gures would not only help to provide
better data for heating, but also for
cooling – providing legislators with the
data required to make industry-affecting
decisions.
HEAT NETWORKS
The introduction of SAP 10 will bring with
it an increase in the default distribution
loss factors associated with heat networks.
Unlike SAP 2012, SAP 10 has reviewed
the losses associated with decentralised
heat networks which will result in a
marginal reduction in the effectiveness of
a connection to a heat network.
This may have consequences for
industry schemes in London where a
stricter reduction in carbon emissions is
being sought for planning requirements.
CHANGES TO BUILDING
REGULATIONS
It is also worth noting that reference has
been made to a consultation for Part L
of the Building Regulations (England
and Wales) before the end of 2018. This
would imply that changes to Part L may
be due to take effect in 2019/2020
depending in the outcomes of
the consultation –
meaning SAP
10 may be
with us
sooner
than we
think.
What’s new for SAP 10?
After much anticipation, the Building Research Establishment
and the Department for Business, Energy & Industrial
Strategy have published SAP 10. Steven Sutton, technical
manager at the Heating and Hotwater Industry Council, looks
at what the changes mean for the industry.
The 55% reduction of electricity’s annual average carbon
dioxide emission factor is an important change for the industry
12 Heating & Plumbing Monthly | OCTOBER 2018 | www.hpmmag.com
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