Greener Church Study Event: St Mary the Virgin, Denby

Friday, 15 May 2026 12:17

Greener Church Study Event: St Mary the Virgin, Denby

St Mary the Virgin’s in Denby near Derby is a beautiful small rural church which dates from the 13^th century.

On February 24^th Forty of us gathered to learn more about their new electrical heating system.

The following is a summary of our discussion.

You can learn more about their project here:

http://www.denbychurch.org.uk/new%20heaters.html

Why was the project done?

Heating a small, rural, ancient church economically and sustainably is difficult. The previous gas boiler and radiators at St Mary’s did not heat the church even after being left on for 6 hours before a service in winter! The heat simply went up and out. Most of the pipes and radiators were 100 years old and leaks had meant that some radiators had been isolated. The boiler was not big enough to give useful heat, and we were wasting a lot of money for no benefit.

The PCC started to think about what could be done, with the pandemic slowing things down a lot. It was difficult to find a heating engineer, when we did, he wrote a specification for a gas boiler system with new pipework and seven fan assisted radiators. We obtained two quotes, which were shockingly high (£60,000 and £77,000). This led to a total rethink.

What did you do?

We were unsure what to do next. This uncertainty and lack of a plan was one of the hardest parts of the whole process.

Part of the Church of England’s approach to net zero has been the development of the ‘’5 Ws’’ ¹

This aims to help decide what is really needed, both now and in the future.

We also used the approach to net zero checklist ²to see what else could be done and identify possible ideas.

We chanced upon an article in Church Times about a new infrared heating system being trialled in a church in Bristol. Two of us visited the manufacturer ³ in Avonmouth twice in early 2023 to understand the technology. The large heater, called a Halo, is suspended from the ceiling and has been designed for heritage buildings. The technology is called “zero-light, far infrared.” The heaters do not emit any light and use a lower frequency of infrared compared to legacy infrared heaters. The frequency is nearer that of the sun’s rays - it does not boil your forehead while keeping your feet cold!

We have two 7.8 kW halo heaters with smaller 2.6 kW ‘Summit’ and 1.9 kW ‘Aspect’ heaters at the sides of the building.

All of this necessitated a new fuse box, distribution board and electricity meter. We also needed switchgear and cabling to the heaters. We were fortunate to already have a three-phase electrical supply, so external work to connect this was not needed.

What were the hardest parts?

Dealing with the uncertainty of how to proceed. We are lucky in having a retired electrical engineer with a wealth of project management experience as a member of the PCC. Other churches will not be in that position. The good news is that people who do have the knowledge and skills are often willing to help.

The other hard part was changing perceptions. People are very familiar with gas boilers and how they heat their houses, by warming all the air in the room. The far infrared (FIR) technology works differently, warming people and objects rather than air. This is a different way of thinking about heating, and some people were sceptical at first.

What other options did you think about and why did you choose this one? We looked at lots of other options. A gas boiler was the easiest to think about as it is very familiar. But as we needed a completely new system it was an expensive option. It would also be ignoring the fact that human induced climate change is happening, and we all need to do what we can to limit this.

Heat pumps and an electric boiler were also considered, but these work by work by heating up all the air in the (big and draughty) church. As the warm air rises, so do the running costs!

After our visit to see the technology in action, we began to think seriously about infra-red heating.

Did everyone agree? If not, how were they persuaded?

Some people were sceptical of the technology. However, they trusted the people who had been looking in detail for a solution to the problem.

Did anything go better than expected?!

We were glad to find that we already had 3 phase electricity.

The company we worked with were excellent. We chose them from a recommendation. Don’t be afraid to pick the contractor who you think will do the best job, even if this does cost more. These are projects which will affect the church for years to come, so it is important to get it right.

Was the diocese involved?

As a Grade I Listed Church, an application for a Faculty had to be made to the Derby Diocesan Advisory Committee (DAC). The following documents were written for the faculty application:

•Project Overview & Plan
•Background & Options Appraisal (including the Five Ws)⁵
•Specification (2 documents)
•A Statement of Significance
•A set of photographs.
•A completed Church of England Checklist called the Practical Path to Net Zero Carbon.

The DAC members asked a few questions prior to their meeting, but the proposal was supported first time. The most important document was the Options Appraisal ⁵ which looked at all possible options for the energy source (electricity, gas, air-source heat pumps, solar panels, etc) and how the heat would be emitted (radiators, under floor heating elements, infrared panels, heated pew cushions, etc). The conclusion was that the only viable and affordable option was the new technology infrared electric system. This system was calculated to reduce the running cost by 66% and reduce the carbon emissions by 88%. The main decision making (by the PCC), planning and preparing the documents took about 8 months. The faculty process took 4 months.

Raising the money

It took five years to raise the money! Few grants for heating systems in churches were available. This situation is improving now. We successfully applied to the following grant making bodies:

•The Benefact Trust
•The Garfield Weston Foundation
•The Raymond Ross Fund (managed by Diocese of Derby) We also received a small grant from the Derbyshire County Council Members’ Community Leadership Scheme, which helped to fund the early specification work.

A church decarbonisation grant is being launched in 2026 which will be accessed through the grant management platform ⁴.

Contact netzero@derby.anglican.org for up to date information about funding.

What was the result?

One of the things that was really important to us was to make better use of the building. It’s a beautiful church, we didn’t want it to stand there, almost unused. We had a small kitchen and toilet extension built a few years earlier, so we just had to make the building more comfortable to be in.

Since the work was completed, the building has seen much more use. This is especially apparent in the autumn and winter months. Last year there were over 40 events between September and December which simply wouldn’t have been possible without the new heating system. With the technology we have chosen, the rapid warm up time means we can switch the heating on a few minutes before the building is needed, rather than hours before with a conventional system.

Is there anything which you would do differently if you were to do it again?

We installed 7.8 kW halo heaters with 1.9kW aspect heaters in the north aisle. These are adequate, but in retrospect it would have been worth spending a little more to spec heaters with a slightly higher output for when the weather is at its coldest.

What would you say to someone thinking about a similar project?

Go for it! The hardest part is making a start.

Be patient. There are many facets to this, and lots of questions to be answered and tasks to be done. It can feel overwhelming at times, but progress will happen.

Be organised.

Take the time to make sure that you know what you want, and why you want it. Have a good look at other examples of option appraisals which have been done by other churches going through a similar process. This will save a lot of time trying to work out what you need to do. Get in touch with netzero@derby.anglican.org for help with this.

References.