Feasibility studies & heat decarbonisation plans
How a building or estate moves off fossil heat: in what order, at what capital cost, at what running cost, and with what carbon saving. Built to be delivered and defended, not filed.
The study a committee can actually use
Decarbonising heat changes the load on the electrical supply, the temperatures the distribution has to run at, the space the plant occupies, the noise outside it and the way the building has to be controlled. A study that considers only the heat source produces a number that turns out to be wrong at the first design stage.
And since the funding stopped, a study that only counts carbon does not get approved. The cases that survive now are condition-led and whole-life costed, with the running-cost consequence stated openly. That is how we write them — see the listed school feasibility for a worked example.
Every option, side by side. Including do-minimum, including like-for-like, including the ones we do not recommend. If the lowest-carbon option costs £3.5m and adds £7,000 a year to the bill, that belongs in the paper.
What a study covers
- Existing heating and hot water systems, age and condition
- Mechanical and electrical infrastructure
- Half-hourly utility data and metered consumption baseline
- Heat demand profile and degree-day regression to a true peak
- Building fabric and load reduction opportunities
- Plant space and external equipment locations
- Electrical capacity, cable rating and DNO reinforcement cost and lead time
- Acoustic constraints and planning considerations
- Operational constraints, phasing and occupancy
- Capital cost, lifecycle cost and annual running cost per option
- Operational carbon by option, at current and projected grid factors
- Funding routes and eligibility as they currently stand
Funding, as it actually stands
| Scheme | Status |
|---|---|
| Public Sector Decarbonisation Scheme (England) | Cancelled June 2025. Phase 4 delivery only, complete by 31 March 2028. No new applications. |
| Low Carbon Skills Fund | No allocation since 2024/25. Phase 5 was the last. |
| Scotland Public Sector Heat Decarbonisation Fund | Phase 3 live. Spend deadline 31 March 2027. |
| Wales Funding Programme | Open. Wales retains a 2030 public sector net zero target. |
| Great British Energy Solar | £255m. Schools, colleges and 260 NHS sites. |
| Green Heat Network Fund / HNES | Open to applications. |
| Condition Improvement Fund | Next round expected autumn 2026. Condition-led, not carbon-led. |
| MEND | Open for eligible museums. |
Position as at August 2026. Scheme rules change; we confirm the current position when you enquire.
How a plan is produced
Data and baseline
Twelve months of metered gas and electricity, floor areas, occupancy and asset information. The baseline everything is measured against.
Survey
Plant condition, plant space, distribution, emitters, electrical intake and the constraints that never show up in a spreadsheet.
Modelling
Heat demand, technology options, capital and lifecycle cost, running cost, carbon per measure, and how the measures interact.
Costed programme
A prioritised, phased plan with cost, carbon and funding route per phase — ready for a board or a funder.
Send us the scope
A building, a stage, a date. We will come back with whether we can take it, what it costs and what we would need from you — usually within a working day.
Your questions, answered
What is a heat decarbonisation plan?
A technical document setting out how a building or estate moves off fossil-fuel heating. It establishes a baseline from metered data, assesses fabric and existing services, identifies feasible technologies, and sets out a costed, sequenced programme with carbon savings, running-cost consequences and funding routes attached.
How long does one take?
Four to eight weeks for a single building from survey to issue. Eight to sixteen weeks for a multi-site estate, depending on the number of sites, data quality and access. Tell us your deadline first — it usually drives everything.
What information do you need to start?
Twelve months of half-hourly or monthly gas and electricity data, floor plans, an asset list or condition survey, details of existing plant and its age, and occupancy and maintenance patterns. Where data is missing we can work from meter readings and survey, but the plan is stronger with it.
Will you tell us to replace everything at once?
No. A plan that ignores when plant is due for replacement will not get funded and will not get built. We sequence against asset life, available capital, term dates or trading patterns, and electrical capacity constraints. Most estates end up with a phased programme over several years.
Do you show options you do not recommend?
Always, including do-minimum and like-for-like replacement. A study that presents one option is asking a committee to take it on trust. Ours show every realistic route with capital, running cost and carbon side by side, so the decision is visibly yours.
Will you tell us if the numbers do not work?
Yes. On one estate we recommended waiting for a district heat network that was not available for two years rather than installing heat pumps immediately, and taking solar in the meantime — which was a smaller fee for us. That is the job.