Heritage church heating specialists

Most churches don't have
a boiler problem.
They have a delivery problem.

We produce independent engineering assessments that find the real cause of church heating failure — and set out a practical, grant-supported path to genuine comfort and lower carbon.

£0*
Cost to eligible churches
via grant funding
16,000+
Church of England churches
with a 2030 net zero target
48wk
Typical turnaround from
survey to report

The problem with church heating

Why the standard approach fails

Most churches are advised to simply replace the old boiler — often with a heat pump. But in a heritage nave with a 9-metre apex, solid masonry walls and an intermittent occupancy pattern, the boiler is rarely the limiting factor. Replacing it without first solving delivery and load will produce a more expensive system that heats no better.

Common assumption

"The boiler isn't big enough."

The old boiler is old, inefficient and unreliable. Replace it with something modern — ideally a heat pump — and comfort will follow.

What we find

The boiler output often matches the heat loss.

At St Anne's the 58.6 kW boiler had headroom over the design loss at the realistic 16°C comfort target. The source was not the problem. The delivery was.

The real issue

Heat is going to the wrong place.

Low-level convective emitters warm air that stratifies into an unheated roof void. Occupants sit in a cold radiant zone regardless of how hard the boiler works.

apex 9.56 m 3.62 m 5.3 m void OCCUPIED ZONE warm air stratifies here cold draught

Building physics

Why a 9-metre nave is a different engineering problem

Warm air rises — away from occupants

Low-level radiators and exposed pipework warm air by convection. That air rises directly into the roof void, typically 5+ metres above the window heads. Occupants in the lowest 1.8 m receive little benefit.

Cold glass drives downdraughts

Single-glazed stained glass creates a cold radiant surface and a convective downdraught along the wall. Even if air temperature is reasonable, the mean radiant temperature at pew level remains low.

Intermittent use defeats pre-heat

High thermal mass means the building cannot be brought to comfort in a 3-hour pre-heat. Short sessions in an under-heated space are the result — not a controllable strategy.

What we do

Three stages.
One continuous relationship.

Each stage builds on the last. Stage 1 generates the evidence; Stage 2 turns it into a design; AR Heating Services delivers it.

01

Stage 1 — Feasibility Assessment

An independent engineering report covering building fabric, heat loss, existing emitter analysis, energy data, occupancy profile and electrical capacity. Sets out a sequenced strategy and provides the evidence base for grant applications.

  • Full site survey by senior engineer
  • Energy and utility data analysis
  • Building physics assessment
  • Decarbonisation pathway with confidence ratings
  • Suitable for PCC approval and grant bodies
From £2,000 + VAT  ·  Often grant-fundable
02

Stage 2 — Concept Design

Following Stage 1, we develop a coordinated concept design: refined heat loss with measured infiltration, emitter schedules, ASHP location review, nave radiant or air-to-air strategy, controls and zoning philosophy, and a capital/carbon comparison.

  • Measured infiltration and temperature logging
  • Full emitter and distribution schedule
  • Electrical max-demand assessment
  • Controls and zoning design
  • Budget cost plan and grant application support
From £4,000 + VAT
03

Installation Management

The Atlas specification is delivered by our installation partner, AR Heating Services Ltd — a company that already understands the building, the constraints and the chosen strategy. Full oversight from survey to commissioning, with conflict of interest formally disclosed at every stage.

  • One relationship from survey to handover
  • Heritage-sensitive installation methods
  • Grant compliance and documentation
  • Post-installation verification and commissioning
8–12% of project value  ·  Projects typically £40k–£200k

How it works

A sequenced approach.
No premature commitments.

We don't arrive with a preferred solution. The evidence determines the strategy — which means no heat source is chosen until the load and delivery picture are properly understood.

1

Initial consultation

A 20-minute call to understand the building, current heating, grant eligibility and what the PCC needs from an assessment.

2

Site survey

Half-day site visit covering geometry, fabric, boiler, emitters, controls, electrical and external plant areas. Utility bills and booking calendar reviewed.

3

Stage 1 report

Fully formatted engineering report with photographs, technical figures and a sequenced decarbonisation strategy, typically within four to six weeks of survey.

4

Stage 2 and beyond

Detailed design, installation and grant drawdown — carried forward only when the evidence from Stage 1 supports it.

A note on grant timing: The Church of England's Decarbonising Churches Grant Fund opened in June 2026. Heritage fabric measures, electrical upgrades and feasibility studies may be eligible for funding — but grant rules change and Atlas does not provide grant advice. We recommend verifying current eligibility with your Diocesan Net Zero Carbon Officer before commissioning any work.

Recent work

St Anne's Church, Eastville

Project profile
9.56
Apex height (m)
58.6
Boiler output (kW)
18.3
Annual gas use (MWh)
~10×
Under-heated vs comfort demand
Source not the problem: At the realistic 16°C comfort target, the existing boiler has headroom over the design heat loss. Boiler replacement alone would not resolve the comfort problem.
Delivery is the problem: All emission is low-level and convective, stratifying into 5.3 m of unheated void. Occupants sit in a low mean-radiant-temperature zone regardless of boiler output.
Direct ASHP on existing radiators rejected: At heat pump flow temperatures the existing emitters roughly halve in output. Naive electrification would deliver worse comfort at higher capital cost.
Assessment summary

St Anne's is a Grade II listed Victorian church with a solid masonry nave, open timber roof to 9.56 m, single-glazed stained glass and an end-of-life atmospheric boiler. The PCC reported poor comfort below 5°C external despite a three-hour pre-heat.

Atlas Engineering completed a Stage 1 Heating Decarbonisation Feasibility Assessment covering building fabric, heat loss, existing system analysis, metered energy data, occupancy profiling and electrical infrastructure.

The central finding was that the existing problem is one of heat delivery mode and position, not heat source capacity. The report set out a sequenced strategy: fabric and load reduction first, then a zoned mixed-technology approach separating the nave from the new low-temperature extension — with the heat source selection deferred until load and delivery are properly quantified.

The PCC received a report they could present to the diocese and grant body with confidence. The assessment was completed within six weeks of the site survey.

Request a sample report →

Funding landscape

Your survey may cost
your church nothing.

The Church of England's net zero programme has opened new grant streams in 2026. A Stage 1 feasibility study is often the first requirement for accessing capital funding. We structure our assessments to align with the evidence grant bodies expect.

Atlas Engineering does not provide grant advice. Eligibility should be confirmed with your Diocesan NZC Officer and verified against current grant conditions before commissioning any work. Grant availability is subject to change.

Decarbonising Churches Grant Fund

Opened June 2026 to churches across all CofE dioceses. Grants in the £3,000–£10,000 range for eligible decarbonisation work including feasibility assessments.

CofE Demonstrator Churches — Stage 1 Grant

Preparatory grants to support churches in developing a net zero action plan including heating assessment and concept design. Confirm current availability with your diocese.

Boiler Upgrade Scheme

£7,500 government grant toward a qualifying air source heat pump. Available to eligible non-domestic buildings. A feasibility assessment helps confirm suitability before application.

Allchurches Trust / Benefact Trust

Grant funding for church building projects including energy improvements. Stage 1 feasibility evidence typically required as part of any capital application.

About Atlas Engineering

Specialist. Independent.
Evidence-led.

Atlas Engineering was founded to address a specific gap in the heritage church decarbonisation market: the absence of independent, engineering-grade heating feasibility assessments. Most churches are advised by heat pump installers with a commercial interest in the outcome, or by generalist consultants without specific expertise in heritage building physics.

We come from the other direction. Our assessments are produced by a building services engineer with direct hands-on experience of heritage church heating systems — the buildings, the constraints, and the occupancy patterns that make them a fundamentally different engineering problem from a school or an office.

We deliberately take on a limited number of assessments each month to ensure senior engineer involvement in every project. We do not subcontract survey work or report writing.

Our installation partner, AR Heating Services Ltd, carries out installation work arising from Atlas designs. This relationship is formally disclosed in writing in every Atlas engagement letter, and clients are always free to appoint their own contractor at Stage 2.

Adam Roberts

BEng (Hons)  ·  Technical Director
  • Building services engineering — mechanical and heating systems
  • Heritage church heating assessment and design
  • Heat pump feasibility and low-temperature system design
  • Church of England grant-funded feasibility projects
  • Installation and commissioning — commercial and heritage
  • Energy data analysis and carbon modelling
Conflict of interest disclosure: Atlas Engineering (consultancy) and AR Heating Services Ltd (installation) are related entities under common directorship. This relationship is disclosed in writing in every Atlas Engineering engagement letter. Clients are not obligated to use AR Heating Services for installation work.

Get in touch

Start with a conversation.

Atlas Engineering

Bristol-based. Working with churches and Diocese officers across England. All assessments involve senior engineer site attendance — we do not send surveyors.