Knowledge: Green Deal
Green Dealing with it
Following the introduction of the domestic RHI and the mandatory requirement
for a Green Deal Assessment, Nish Dattani, director of Green Assessors, explains
what is entailed in the process and highlights some of the challenges and
concerns being raised by installers
What’s involved in a Green Deal Assessment?
The Green Deal Assessment (GDA) comprises of two aspects; an
Energy Performance Certifi cate (EPC) and an Occupancy Assessment.
The EPC shows the current and potential energy effi ciency of the
home and is the basis under which the deemed kWh usage is derived
to determine the RHI income. The Occupancy Assessment involves
a more detailed analysis about the householder’s lifestyle and energy
usage. The aim of this is to gain a better understanding of how the
property is used and to provide a better indication of the appropriate
energy effi ciency and renewable energy improvements and the cost
savings likely to be achieved.
Why is the heat loss calculation performed by an installer
different to that determined by the EPC?
The key aspect of the domestic RHI is the deeming calculation,
whereby the householder is paid for every unit of renewable heat
generated as derived from the EPC. Often the notional heating and
hot water demand derived from the EPC is very different from that
estimated by the installer. The main reason for the difference lies in
the implicit assumptions that underpin the EPC assessment, which
is based on Reduced data Standard Assessment Procedure (RdSAP)
methodology. The EPC assessment does not refl ect occupancy and
incorporates standardised assumptions around running hours and
internal mean temperatures. The installer is sizing the heating system
to meet the demands of the property and its occupants and is focused
on worst case scenarios, so as to ensure demand for heat and hot water
is always met.
The differences can be quite signifi cant and this poses a diffi cult
challenge for the installer to advise accordingly and may affect the
investment decision by the householder as to whether to proceed
with an installation. Our advice to installers is to encourage the
householders to get a GDA carried out early in the process, so as to
defi nitively determine the level of RHI income they will receive.
Why are the energy cost savings estimated by the installer
very different to that presented in the Green Deal Report?
Often installers will present an estimate of the running cost savings
for a householder moving from a fossil fuelled heating system to a
new effi cient renewable heating source based on the heating demand
for the property as determined by their heat loss analysis. However,
the Occupancy Assessment estimates the likely cost savings in
relation to the actual energy usage and consumption. For those
householder’s that are low energy users the running costs savings can
be signifi cantly lower than those presented by the installer.
What else can the Green Deal Assessment help with?
The Green Deal Assessment helps to identify and recommend the
energy effi ciency measures that are appropriate for the property and
the savings likely to be achieved. Our advice is always to focus on
fabric fi rst and there a number of grants and cashback incentives
currently available. The government has recently announced the Green
Deal Home Improvement Fund which allows householders to claim
cashback of upto £7,600 after installing a range of measures, with up-to
£6000 available for solid wall insulation.
What is clear, given the level of confl icting information, is for
installers to partner with credible Green Deal assessors who not
only understand renewable heating technologies but are able to
advise householders on the wider RHI & Green Deal policy and the
implications the assessment will have on their RHI income.
Simple solution: The Green Deal Assessment process needn’t be
daunting for installers as long as they partner with a reputable assessor
organisation, says Nish Dattani, director of Green Assessors
www.renewableenergyinstaller.co.uk | 17