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Renewable Energy Design Statement
Proposed Extensions and Refurbishment for Lea Rowing Club
The Boathouse, Spring Hill, Clapton, London E5 9BL
Report Prepared by
Richard Bonshor RIBA
3 Church Close
Bucklesham
01473 659915
[email protected]
Scope of Report
This document has been prepared to accompany the planning application to extend and
partially rebuild Lea Rowing Club based upon the scheme shown on the application drawings.
The report is limited in scope to reflect the design at its current level of detail. In some
sections it provides a statement of intent to demonstrate how a particular aspect of design or
approach to a sustainable energy strategy has been considered but which will only be fully
documented or detailed when the construction stage of the development is reached.
It would be unreasonable to require financial expenditure proceeding to a detailed design
phase until such time as a (conditional) planning permission had been granted. It is expected
that conditions could be attached to any consent requiring submission of further details or
information where that is considered necessary to further substantiate the energy use of the
development.
1.
General Approach and Overview
There is a commitment to minimize the energy demands of the development (and hence future
running costs). Wherever it is financially viable to do so, this will be over and above the
requirements of the Building Regulations. Given that much of the funding for the proposed
development will come from general ‘fundraising’ rather than existing capital, we will judge
the (additional) capital outlay required against a 15 year initial ‘payback’ period.
The existing site comprises three buildings, the café, Tyrell’s boathouse and the main
boathouse. No significant works are proposed to the first two buildings, the café is a stand
alone building and Tyrell’s is used only for boat storage and is unheated. It is the main
boathouse and ancillary areas which are to be extended and upgraded as part of this
application and it is those areas which are addressed within this report.
2.
Existing Buildings:
2.1
Boat storage areas are unheated and lighting is by fluorescent tube fittings.
Other building areas are heated via a LPHW system and hot water is provided via a gas boiler
and hot water storage cylinders. The existing building fabric has minimal insulation to walls,
and the existing industrial (profiled fibre cement) roofing and separating floor over the
unheated boat storage areas. The building has a mixture of light fittings but fluorescent fittings
predominate.
2.2
The parts of the existing building (remaining as part of the re-development) will be
enclosed on two faces by the new/ rebuilt parts of the site. In addition it is planned that the
remaining external walls and roof will be substantially over hauled with new double glazed
windows, roof lights and doors, together with upgrading of the thermal insulation to exposed
and semi-exposed elements to at least current Building Regulation standards. This in itself will
dramatically reduce the requirements for space heating within the existing buildings which are
to be retained.
3.
New Buildings:
3.1
It is proposed that a ‘fabric first’ approach is the starting point for the energy policy
for the new sections of the building. The detailed construction specification will exceed the
current requirements of the Building Regulations for levels of insulation, air tightness and
ventilation.
In addition provision will be made to include mechanical ventilation and heat recovery
(MVHR). The existing gas boiler is relatively new and was sized to supplement the additional
space proposed by the new development. There will be a need to incorporate additional zone
controls and timers to allow for maximum flexibility within the new development.
3.2
Energy efficient lighting will be installed throughout the development, with provision
for generous natural light via windows, roof lights and glazed doors wherever possible and
practical to suit the room layouts.
3.3
Kitchen fittings lift installation, electric equipment and ancillary fittings will all be
required to achieve a class A energy rating.
4.
Renewable Energy:
The different sources of renewable energy have been considered to complement a highly
insulated building fabric together with the particular constraints of the site and existing
buildings.
4.1
Solar Heating for Hot Water.
Other than space heating there is a substantial requirement for hot water for showers and
toilet facilities. Given the extensive roof area of the new development, much of it facing due
south, it would make long term sense to utilize some of that space for a system of solar panels
to provide hot water for the development. At this stage of the design process, a detailed design
has not been commissioned however there is ample panel space available to allow for an
optimum solution, with appropriate levels of hot water storage.
The existing gas boiler will be available for ‘top-up’ provision.
4.2
Space Heating
4.2.1 Consideration has been given to the use of heat pump technology.
Initial investigations have suggested that the adjacent waterway would be a prime source of
‘free’ heat however this has been discounted at present due to:
(a) Extra capital outlay and cost of consents associated with obtaining British Waterway
approval and carrying out disruptive works within the towpath and to the waterway itself to
make the necessary connections.
(b) Costs associated with mitigating the chilling effect of the ‘used’ water and the need to
extend works beyond the current site boundary.
(c) On going charges from British Waterways for the continuing use of the waterway as a heat
source. The long term energy supply for the building would be locked into a single supplier with
no option for competitive pricing.
4.2.2 A possible alternative under consideration is to utilize ground source heat pumps linked
to boreholes within the site boundary. The potential of such a system will be carried out at
detailed design stage, assuming planning permission is granted. There is, however, significant
flexibility in the design (depth) and number of boreholes required to provide sufficient heat.
This would be linked to a system of under floor heating throughout the new buildings – the
slightly lower operating temperatures being well suited to the main gym and bar areas. By
employing this system the installation would be self contained without associated ongoing fees
and charges to third parties, however this system is well down the list of sustainable options.
Where practical the under floor heating would be extended into the existing building however
existing construction may make this impractical in which case the existing gas heating would
remain.
4.3
Photovoltaic Arrays
4.3.1 Subject to the final detailed design it may be viable to utilize photovoltaic arrays on
part of the south facing roof slopes, for example, to power the heat pumps. This may well
hinge on the incentives available at the time of construction and at present it remains a factor
under consideration. A final decision on whether or not the financial outlay and ‘payback’
period can be justified would be taken during the detailed design phase of the development. At
present it appears more likely that enhanced insulation and MVHR would be a more cost
effective option.
4.4
Wind Turbines
4.4.1 Given the low lying and relatively sheltered location of the site, it is not considered
likely that sufficient energy would be generated by any form of wind turbine that could be
justified in terms of ‘payback’. It is suggested that this is the least likely form of renewable
energy suited to this site and building. Windy conditions are not conducive to rowing activities
so periods of peak generation would run counter to peak periods of demand.
4.5
Combined Heat and Power (CHP)
4.5.1 A further system to be fully evaluated is a combined heat and power engine to replace
or run in tandem with the existing gas boiler. The potential of such a system will be carried out
at detailed design stage, assuming (conditional) planning permission is granted.
5.
Current Approach
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The current design starts from a point of ‘fabric first’ and utilizing energy efficient
fittings and appliances.
A solar hot water system is to be employed to serve toilets and showers.
Photovoltaic panels could be easily integrated into the roof of the development with
minimal impact with final proposals linked to feed-in tariffs. An optimum system will
be carried out during the detailed design stage.
CHP will be given a detailed evaluation and costing when a planning permission is in
place due to the further level of detailed design and associated cost required. This will
need to be balanced against replacing the existing gas boiler.
Heat pump options require a more detailed evaluation and costing which will be carried
out when a planning permission is in place due to the further level of detailed design
and associated cost required.