Gas Boiler, Heat Pump or Pellets? Heating Small Premises
When the old boiler in your shop, studio or small office starts making strange noises, the big question arrives fast: replace like for like, switch to a heat pump or try wood pellets? This guide compares the three options on the costs that actually matter for small premises, explains where grant schemes stand in the UK, Germany and France, and gives you a simple template to run your own numbers.
Key takeaways
- Compare heating options on the full picture: upfront cost, running cost, maintenance, insulation, space and noise rules, not just the price of the unit.
- In England and Wales, the Boiler Upgrade Scheme gives grants toward heat pumps. Check the current amount on Ofgem.
- Germany's reformed heating law (now the Building Modernisation Act) took effect in July 2026. New gas heating is allowed again, and working systems do not have to be replaced.
- In France, MaPrimeRénov' supports heating upgrades, so check the current conditions before you sign a quote.
- Rule of thumb: insulate and seal drafts first, then choose the heat source.
Heating is a cost many small business owners notice only when the first cold week arrives or the bill lands. Yet the system you pick will shape your running costs for many winters, so an afternoon of careful comparison now beats a rushed decision after a January breakdown.
This article is written for owners of small premises such as a shop, a workshop, a salon, a small office or a mixed home and work building. It is general information, not legal, tax or engineering advice. Grant rules and building regulations change, so confirm the details with an accredited installer, an energy advisor or the official scheme websites before you commit.
The three options in plain terms
Before comparing costs, it helps to be clear about what each system does and what it needs from your building.
Gas boiler
A gas boiler burns natural gas to heat water, which then flows through radiators or underfloor pipes. It is the familiar choice in much of the UK and Germany. Installation is usually straightforward if you already have a gas connection, and boilers produce high water temperatures, so they work with older radiators sized for that heat. The trade-off is that your running cost tracks gas prices, and climate policy in Europe is steadily pushing toward lower-carbon heating.
Heat pump
A heat pump moves heat from outside air (or the ground) into your building using electricity. Air-source heat pumps have an outdoor unit, roughly the size of a large air conditioning box, connected to the heating system inside. They tend to run best at lower water temperatures, which is why insulation and radiator size matter so much. Your running cost follows electricity prices and how efficiently the system is designed and set up.
Wood pellet boiler
A pellet boiler burns compressed wood pellets, fed automatically from a hopper or a storage room. It can produce high temperatures, which suits some older buildings, and it uses a renewable fuel. The catch is space: you need room for the boiler, a dry pellet store and access for deliveries, and someone has to keep an eye on ash removal and servicing.
What to compare: the six cost factors
A heating quote usually shows one big number. To compare fairly, break the decision into six parts and score each option against your own premises.
- Upfront cost. The unit, installation, any pipework or radiator changes, electrical upgrades, a flue or chimney liner, and removal of the old system. Ask each installer to itemize these lines.
- Running cost. What you will pay for fuel or electricity each year. This depends on local gas, electricity and pellet prices, how much heat your building loses and how efficiently the system runs. Get the installer to explain the assumptions behind any estimate.
- Maintenance. Annual servicing, safety checks, filter cleaning, ash removal for pellets and the likely cost of common repairs. Ask what the warranty covers and what it requires from you.
- Building insulation. A drafty, poorly insulated space wastes heat whatever the source. Heat pumps in particular may need larger radiators or better insulation to keep the space comfortable efficiently.
- Space. A heat pump needs a spot for the outdoor unit. A pellet system needs room for the boiler and a dry pellet store with delivery access. A gas boiler needs a gas supply and a flue.
- Noise and local rules. Outdoor heat pump units make some noise, so check local noise rules and how close the unit would be to neighbors. If you rent, your lease and landlord may restrict what you can install.
Pro tip
Ask every installer the same five questions and write the answers in the same table: total installed price, expected yearly running cost and the assumptions behind it, service cost, warranty terms and installation lead time. Identical questions make quotes comparable.
Grants and rules in the UK, Germany and France
Public support can change the math considerably, but schemes have conditions, application steps and sometimes limited budgets. Treat this section as a starting map, then check the official source for your country before you sign anything.
UK: the Boiler Upgrade Scheme
In England and Wales, the Boiler Upgrade Scheme gives grants toward heat pumps. The amount and eligibility rules can change, so check the current figure and conditions on Ofgem before you plan your budget. Ask your installer how the application works for your premises and how the grant is shown on the quote.
Germany: the Building Modernisation Act
Germany's heating law has been one of the most discussed small business topics of the past few years. A reform took effect in July 2026 and renamed it the Building Modernisation Act. The main points for owners of small premises:
- The requirement that new heating systems use 65% renewable energy was removed, so new gas heating is allowed again.
- New gas systems will need a rising share of green fuels from 2029, so factor that into long-term running costs.
- Working systems do not have to be replaced. If your current boiler runs well, you are not forced to rip it out.
- KfW heat pump subsidies continue under revised guidelines from 21 July 2026. Check the current rates with KfW before applying.
France: MaPrimeRénov'
In France, MaPrimeRénov' supports heating upgrades, including moves to lower-carbon systems. Conditions depend on the type of work, the property and the applicant, and they have been adjusted several times, so check the current rules on the official MaPrimeRénov' site and confirm whether your premises and project qualify before work starts.
Common mistake
Signing a quote or starting work before the grant is confirmed. Many schemes require you to apply, or to use an approved installer, before the work begins. Get the grant steps in writing first, then book the installation.
Pros and cons side by side
No option wins everywhere. Here is how they tend to compare for small premises, in general terms.
Strengths
- Gas boiler: familiar, usually simple to swap if you already have gas, works with existing radiators.
- Heat pump: runs on electricity, lower-carbon, can pair with rooftop solar, grants available in several countries.
- Wood pellets: renewable fuel, high water temperatures for older buildings, an option where there is no gas grid.
Watch-outs
- Gas boiler: exposed to gas prices and to future rules on greener fuels.
- Heat pump: design and insulation matter, may need larger radiators, outdoor unit needs space and noise checks.
- Wood pellets: needs storage space and delivery access, more hands-on maintenance, ash removal.
A heating cost comparison template
Copy this table into a spreadsheet and fill in one row per quote. All amounts below are made-up examples for illustration only, not real prices. Replace them with the figures from your own quotes and bills.
| Option | Installed price (example) | Grant (example) | Yearly running cost (example) | Yearly service (example) | Space needed | Notes |
|---|---|---|---|---|---|---|
| New gas boiler | £3,000 | None | £1,800 | £120 | Existing boiler spot | Check future fuel rules |
| Air-source heat pump | £11,000 | £5,000 | £1,400 | £150 | Outdoor unit, side yard | Two radiators upsized |
| Wood pellet boiler | £12,000 | None | £1,600 | £250 | Back room for pellet store | Delivery access via lane |
Then add a final column for "10-year total" (installed price minus grant, plus ten years of running and service costs). The made-up numbers are only there to show the method. Your real figures could point to any of the three options.
Hypothetical example
Imagine Priya, who runs a small yoga studio on the ground floor of an older terraced building. Her gas boiler is 18 years old and needs a costly repair. Before choosing, she gets an energy check and learns that the front door and old sash windows leak a lot of heat. She spends a modest amount sealing drafts and adding insulation to the ceiling first. With the building holding heat better, a heat pump quote now needs fewer radiator changes. She fills in the template with three quotes, checks the grant rules and decides on the option with the lowest 10-year total she can comfortably afford upfront. A neighbor with no outdoor space reached a different answer, which is why you run your own numbers.
Practical steps before you choose
Use this order to avoid paying for the wrong system or the wrong size.
Start with the building
Walk around your premises on a cold, windy day. Feel for drafts around doors, windows, letterboxes and pipe openings. Check the loft or ceiling insulation where you can reach it. Cheap fixes such as draft strips, door brushes and thermal curtains can make the space more comfortable this winter, whatever you decide about the heat source. If you also look after a home, our guide on winterizing a house covers similar ground.
Check your current system honestly
If your boiler works and is serviced, you may not need to replace it right now. In Germany, working systems do not have to be replaced under the reformed law. A good service and a few repairs can buy you time to plan, save and wait for the right grant window. For a simple service routine, our HVAC maintenance checklist is a useful starting point.
Talk to your landlord early
If you rent, the heating system usually belongs to the landlord. Ask who pays for what and whether the lease allows an outdoor unit or a pellet store, and get it in writing.
Get at least three quotes
Ask accredited installers for a site visit and a heat loss assessment rather than a quote by phone. Use the same questions with each one, and be wary of anyone who sizes a system without measuring the building.
Your heating decision checklist
- Check for drafts and missing insulation, and fix the cheap items first
- Note the age, condition and service history of your current system
- Collect last year's gas or electricity bills to see your real heating use
- Ask your landlord about ownership, permission and cost sharing if you rent
- Check the current grant rules on Ofgem, KfW or MaPrimeRénov' for your country
- Measure space for an outdoor unit or a pellet store, and check noise rules
- Get three itemized quotes with running cost assumptions and warranty terms
- Fill in the comparison template and work out a 10-year total for each option
- Confirm grant approval before you sign and book the installation
Frequently asked questions
Do I have to replace my gas boiler in Germany?
Not if it works. Under the Building Modernisation Act, which took effect in July 2026, working systems do not have to be replaced, and new gas heating is allowed again. New gas systems will need a rising share of green fuels from 2029, so think about long-term fuel costs if you install one.
Will a heat pump work in an older building?
It can, but the design matters. Heat pumps usually run best at lower water temperatures, so poor insulation or small radiators can make the space feel cool or push running costs up. Ask an installer for a proper heat loss assessment and fix drafts and insulation first.
Is wood pellet heating a good choice for a shop?
It can suit premises with no gas connection and enough dry storage space with delivery access. If space is tight or nobody can look after ash removal and servicing, a heat pump or gas boiler may be easier to live with.
How do I find out how much grant I can get?
Check the official source for your country: Ofgem for the Boiler Upgrade Scheme in England and Wales, KfW for heat pump subsidies in Germany, and the MaPrimeRénov' site in France. Amounts and conditions change, so check close to the time you apply.
Related reading
The bottom line
There is no single right answer between a gas boiler, a heat pump and wood pellets. The best choice for your premises depends on the building, the space you have, the grants available where you are and the running costs you can live with for the next decade. Insulate and seal drafts first, then compare itemized quotes on their full cost rather than the headline price.
Block out an afternoon this week, gather your bills, walk the building and fill in the template with real quotes. A calm, well-planned decision now is far cheaper than an emergency replacement in the coldest week of the year.
