Findings from LEAF (Local Energy Assessment Fund) project to audit the
energy use of 52 churches in the Diocese of Gloucester and make
recommendations on how to save energy and cost
Introduction
There are nearly 400 churches in the Diocese of Gloucester. 90 per cent of them are listed buildings, 38
per cent being grade one. 52 churches were visited by Sustain auditors in March-April 2012. All churches
in the Diocese were invited to participate with those chosen being the ones that expressed an interest.
The findings are a valuable source of information for other Dioceses and heritage bodies.
This report introduces the characteristics of the churches audited followed by the figures on energy spend
and carbon footprint headlines before going into more detail about the recommendations made. Where an
average figure is given it is the median average as the wide variation of results means this a more
appropriate way of determining an average.
Building characteristics
The churches audited range in age from 750 to 1992 with listings of grade 1, 11, 11* through to
unclassified. They range from rural churches used for 7 hours a month up to town centre churches
attracting tourists and open for 233 hours per month. In terms of size the floor areas ranged from 90m 2 to
1320m2 and congregation sizes from 10 to 200. As you would expect there was a positive correlation
between annual CO2 footprint and floor area and annual CO2 footprint and congregation size (see graphs
in appendix). There was no correlation between annual CO2 footprint and age of church or congregation
size.
Energy spend
The total energy spend for each church ranged from £211 to £17,680 per year with the average being
£1,539.
The average annual spend on electricity for power and lighting was £500 with the lowest being £73 and
the highest being £6,137. The average annual spend on heating (oil and gas) was £1,410 and with the
lowest being £73 and the highest being £11,543.
The tariff the churches paid for utilities varied greatly and is tabulated below. Of particular note is the
finding that the highest tariff paid for electricity was 250% higher than the lowest.
Cost range
(p/kWh)
Cost average
(p/kWh)
Electricity
5.6 - 19.6
10.0
Gas
2.0 - 7.5
3.7
Oil
4.1 - 7.7
5.6
Table 1. Cost, range and average for each utility for all churches audited
The above costs are for the energy only and do not include standing charges, VAT etc
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The Diocese of Gloucester has partnered with Ecotricity to offer green electricity to their churches at
8.27p/kWh off peak (which covers Sundays) and on peak at 11.77p/kWh with a standing charge of 54p.
18% of churches were using this scheme. Of those remaining, 29% would definitely benefit from
transferring to it and 44% would possibly benefit. Despite this some church wardens reported not knowing
about the scheme. It goes without saying that as much of church use is on Sundays and evenings, the off
peak rate is particularly relevant when procuring a tariff.
If energy tariffs were to rise by just 10% then this would add on average £236 per church per year.
Carbon footprints
The total carbon footprint for each church ranged from 1 to 143 tonnes CO 2 per year with the average
being 7.7 tonnes CO2 per year. For the churches that weren’t electrically heated the carbon footprint was
made up of 30% on electricity for lighting and power and 70% on heating.
Benchmarking
It is conventional to benchmark buildings on energy usage per m 2 however we propose that it is more
relevant to benchmark churches on energy usage per hour of occupancy. This is because the occupancy
varies so much and the majority of energy usage correlates directly with when the building is occupied.
Therefore we have not provided here any results on energy usage per m 2 but instead present below
figures based on occupancy. The one limitation of this method is that there is a margin of error in the
figure for hours of occupancy as this had to be estimated by each church warden based on their
recollection of how each church is used throughout the year. The data on cost per hour of occupancy will
be of particular interest to church management committees when considering what they should charge to
organisations renting their church space.
kWh per hour of
occupancy
range
kWh per hour of
occupancy
average
Cost per hour of
occupancy
range
Cost per hour of
occupancy
average
Electricity
(power and lighting)
3 - 78
12
£0.41 – £7.35
£1.29
Gas heating
6 - 346
97
£0.37 - £12.67
£3.61
Oil heating
29 – 342
99
£1.63 - £18.51
£6.50
Table 2. kWh and cost per hour of occupancy, range and average, for each utility for all churches audited
As the annual kWh for oil heating has to be based on deliveries it is impossible to accurately estimate the
exact annual consumption unless the deliveries are made on exactly the same day each year.
Metering and billing issues
Not all the churches were keeping a close eye on their energy bills. 8% of churches did not provide
energy bills to Sustain as they did not have easy access to them. Our analysis of the energy bills we did
receive proved very revealing and we found 10% of churches had metering or billing issues of different
natures.
Churches are eligible for a reduced rate of VAT of 5% and this was being wrongly applied in 4.7% of
cases where the standard rate of 20% was being paid. This number of churches would have been one
higher if it wasn’t for a diligent treasurer who had spotted the error and corrected it midway through the
last year. One church was also paying the climate change levy which is wholly incorrect.
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One church had 3 electricity meters and was hence paying 3 lots of standing charges. Meter timeclocks
were another source of error. One had the off peak times incorrect which was costing the church an
additional £150 per year. Another had a meter reading that bore no resemblance to the reading on the
bills.
The worst case was a church where firstly, the incorrect time was showing which meant the recording of
peak and off peak electricity was incorrect. Secondly (and more significantly) the church was being billed
the wrong way around for peak and off peak electricity, the higher peak charge being applied to the off
peak meter reading. As there is considerably more off peak than peak use at the church (as off peak
covers all day on Saturday and Sunday) the error is estimated to have resulted in over charging in the
region of £500 over the last 18 months and is likely to go back further than this.
Correcting metering and billing issues is a no cost measure that can save a valuable amount of money
and all church treasurers should be checking for these metering and billing issues. As part of this project
Sustain set all the churches up with access to an online tool where they can record their energy readings
and compare them against other churches in the Diocese. This will encourage closer monitoring of
energy consumption and spend.
Recommendations
Sustain’s audits revealed many measures that could be taken to reduce energy in every church. Some of
the measures will payback within a few years however due to the low usage of some of the churches and
high cost of some of the measures the paybacks will be much longer. This should not be viewed as a
barrier to investment. Churches and other heritage buildings are unique in that they will be preserved for
hopefully many hundreds of years to come and so paybacks of over 10 years are small in the overall
timescale. These measures should be viewed as investing in the asset for future generations. Many of the
measures would also improve comfort for congregation and the resultant increase in well being and
attendance should also be valued.
It is always wise to check with the Diocese if any of these measures require a faculty but it many cases
they can be done without needing a faculty even when a church is listed. It goes without saying that
energy efficiency should be an essential part of any re-ordering works when the opportunity arises.
The energy savings measure recommended along with the percentage of churches they applied to is
shown in Table 3 below.
Measure
Internal lighting lamps
Draught proofing to ext. door(s)
Floor insulation (pews and ducts)
Label light switches
Reflective radiator panels
Insulate pipework in boiler room
Heated air curtain
Repoint/repair/seal windows
Loft insulation
Thick curtain to door
Glycol and remove frost stat
Reprogram timer to heating
Vphase
Clean filters in forced air fan convectors
Roof insulation
External lighting lamps for LEDs/CFLs
% of churches
88%
58%
42%
40%
33%
33%
33%
33%
31%
31%
29%
29%
25%
23%
23%
21%
3
Other heating
Other electrical
LED light fittings
Boiler replace
Reset frost stat
Insulate underfloor pipework/reflective foil
Photocell/PIR/timer on outside lights
Insulate pipework in space
Reset thermostat
Replace/install thermostat and/or
programmer
Tower insulation
Under pew electric heaters
Cavity insulation
Only heat occupied part of church
TRV controls to radiators
Switch to gas heating
Reflective foil in pipework trenches
Secondary glazing
Lay carpet to vestry
21%
19%
17%
17%
17%
17%
15%
13%
12%
12%
12%
10%
10%
6%
4%
4%
2%
2%
2%
Table 3. Energy efficiency measures recommended
Electricity (non heating)
The top measure which applied to almost every church (88%) was to upgrade the lighting to more
efficient compact fluorescents (CFLs) and LEDs alternatives. Often this could be done by just replacing
the lamp but sometimes the fitting needed to be replaced. For each church, we calculated the kWh
savings that could be achieved by upgrading the lighting which gave the average saving as 940kWh or
£94 per annum. We also provided each church with the cost of purchasing the replacement lamps and
fittings, many of which could be installed by them without the need for an electrician. The biggest kWh
savings were achieved by replacing external sodium light fittings with CFL clusterlites. On one large
church this investment will payback in 6 months and save £1000 per year.
It was acknowledged that some of the light fittings are at high level and difficult to access without a cherry
picker but low energy lamps do blow less often than high energy equivalents and so once installed
access should be required less often.
Voltage optimisation technology such as V phase for single phase systems was recommended in 25% of
cases costing about £400 and saving £40 per year. This technology is too costly for three phase systems
considering the low occupancy.
We were impressed to find that there was virtually no energy being wasted by plug in appliances being
left on when the churches were unoccupied.
Heating system efficiency
47% of churches were heated by gas, 29% by electric and 24% by oil. As many of the churches were
rural, gas was not always available as an option for heating. Sustain’s research revealed that for these
churches where the hours of occupancy are also low it is cheaper to heat with electricity rather than oil
(see Graph 1 below). A lower carbon alternative would be to use wood pellets. Sustain has direct
experience of a wood pellet boiler installation in a rural church within the Diocese although it was not
included in this research project.
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£3,500
Annual energy spend
£3,000
£2,500
£2,000
Gas
£1,500
Electricity
Oil
£1,000
£500
£0
50
100
150
200
250
300
350
Hours of occupancy per year
Graph 1. Graph to show annual energy spend against hours of occupancy for different heating fuels (for
the 30 churches with lowest occupancy)
Every church had a different heating design and specification. There were variations in local heating at
pews versus heating the whole space, radiant heating versus air heating and whether heating should be
on low for longer or high for a shorter length of time.
The control of heating systems was an area where savings can be made. Most systems had frost
protection where the heating system will come on when the air temperature drops below a critical
temperature in order to avoid the risk of burst pipes. This critical temperature varied greatly between
churches with one being as high as 9 degrees when 2-3 degrees is sufficient. A low energy alternative to
this is to fill the heating system with a glycol antifreeze and avoid the need to run the heating when the air
temperature is low.
Heating systems which are just controlled by timeclock should have the pre-heat time adjusted for the
seasons. The timeclock can also be set to switch off before the end of services as the heavyweight nature
of the building means it should retain heat for a good length of time following switch off. There were
occasions where background heating was being used to protect against damp and this could linked to a
humidistat control as it may be that it is not needed in summer.
Insulation and draught proofing
There were 31% churches where loft insulation may be suitable but concerns were expressed on access
and over how this would affect ventilation to the fabric of the building. It is preferable that roof insulation
(23% of cases) and possibly also loft insulation is added when re-roofing works take place. Tower ceilings
should also be insulated. As cavity wall insulation is only relevant to modern buildings this was only
applicable in 10% of cases.
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Draught proofing the floorboards of the pews and insulating beneath them proved to be a popular
measure with it being recommended in 42% of cases. This would also have a large impact on perceived
comfort which may allow space heating temperatures to be turned down.
There was some debate about the most appropriate method of draught proofing the main entrance doors.
When the congregation is arriving the most effective option would be a high velocity or heated air curtain
but the capital cost of this is hard to justify on energy savings alone. When the church is not in use a thick
fabric curtain would be suitable but the lowest cost option would be to draught seal the doors.
Some churches had uninsulated pipework running through the occupied space and in floor trenches.
Whilst this is providing heating to the space indirectly it is not an efficient method of heating as it is not
concentrated where the congregation will sit and heat will be lost to heating the building fabric. Insulating
pipework in concealed floor trenches is admittedly very difficult but anywhere that reflective foil, insulation
board or insulation covers can be added would be of benefit. This would also help protect against burst
pipes.
Renewable energy
Despite the perception that listed buildings cannot make use of renewable technologies we found there
were many opportunities for them to be included as shown below.
Measure
Solar photovoltaics
Biomass/wood pellets
ASHP
Micro hydro
Solar thermal
GSHP
Wind
% of churches
50%
35%
12%
4%
2%
2%
0%
Table 4. Renewable energy measures recommended
50% of churches could have solar photovoltaics installed despite many of them being listed. This is
because the arrays would not be visible from the ground and hence are more likely to be granted
planning permission. Alongside this project Sustain also undertook a wider exercise using aerial
photography to establish the feasibility of installing solar photovoltaics on each of the nearly 400 churches
in the Diocese.
Biomass and air source heat pumps were recommended for further investigation mainly where electricity
was the primary heating fuel or where the existing oil boiler was due for replacement.
Ground source heat pumps were only suitable in one situation as the graveyards surrounding the
churches limited the amount of suitable space available. Micro hydro was only applicable to two sites as a
suitable body of water in the vicinity is required.
Appendix
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160.00
140.00
Annual CO2 footprint (tonnes)
120.00
100.00
80.00
60.00
40.00
20.00
0.00
0
-20.00
200
400
600
800
1000
1200
Floor area
Graph showing values and positive correlation between annual CO2 footprint and floor area.
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1400
160.00
Annual CO2 footprint (tonnes)
140.00
120.00
100.00
80.00
60.00
40.00
20.00
0.00
0
50
100
150
200
250
Hours use per month
Graph showing values and positive correlation between annual CO2 footprint and hours use per month.
8