Heat pump or boiler? Solar or battery? Insulation first? Every supplier sells you their answer. You're left guessing whether it's the right one for your house.
Book a free 15 minutes with a Master's-trained renewable energy engineer. We listen to your problem, look at your photos, and tell you what we'd actually do. Honest. Tech-agnostic.
If any of this sounds familiar
If your house doesn't quite work the way the brochures said it should, you are not alone. Here's what we hear most often. Click any one to start a free 15-minute call about it.
Two bathrooms, one combi, no pressure. A system change, an unvented cylinder, or an accumulator could fix it — the right answer depends on flow rate, demand pattern and house size.
Talk it through 02 · Heating controlBedrooms baking, kitchen freezing, bills going up. Zoning a heating system properly is mostly plumbing and a bit of physics — and far cheaper than people think when done right.
Talk it through 03 · Older homesPre-1970s solid-wall construction, draughty floors, single-glazing remnants. The order matters: insulation, then heating, then renewables. Most people do it backwards and waste thousands.
Talk it through 04 · Heat pumpsIt depends on your radiators, your insulation, your hot water demand and your roof. We've seen brilliant heat pump installs and disastrous ones. The difference is a 30-minute conversation upfront.
Talk it through 05 · Solar & batteryThe maths changes with your usage pattern, your tariff and your roof. Sometimes a battery pays back in five years, sometimes it never does. Run the numbers properly before signing.
Talk it through 06 · Smart homeThe thermostat got smart but the system underneath didn't. Often it's flow temperatures, weather compensation, or the heating curve. Fix the boiler's brain, not the wall display.
Talk it throughFour shapes of help, prices visible
The free 15 minutes is the front door. The next three are situational — pick the one that fits your house. No day rates. No retainers. No hidden costs.
Anyone with a problem and 15 minutes. Most homeowners will find this is enough to know what to do next.
If the call uncovered something worth doing, we'll sketch it on your existing drawings or photos. Plumber gets a parts list they can quote against.
Bigger or older properties — 5+ bedrooms, 4+ bathrooms, awkward existing systems — need eyes on. We attend, measure, photograph, and write a scope of works your plumber can follow.
If your plumber wants a second pair of eyes on a tricky install, we attend on an hourly basis. Problem-solving billed by the problem, not chair-warming. Hours logged, agreed in advance.
We believe you won't need this unless your existing install has gone bad.
What you actually get to keep
After the call, after the sketch, after the survey — you walk away with a simple diagram of how energy moves through your home. We call it a digital twin. Big firms sell this for thousands and lock it inside their app. We hand you the file.
01
On a small device the size of a phone charger. It does not sit on our server, the manufacturer's server, or anyone else's server. Ever.
02
Standard plumbing for sensor data — the same kind hospitals and factories use. If you ever change tools, the file moves with you.
03
No subscription, no contract beyond what we agreed for the job. If we stop adding value, the right answer is for us to leave.
Most consultants sell you that capability locked inside their platform on a multi-year licence. When the contract ends, the dashboard goes dark — and the data goes with them. We do it the other way round.
How we work, on a real job
No stock illustrations. No AI mock-ups. This is the actual five-stage process we follow on a Bluebell job — the marked-up sketches, the M&E drawings, the tender package, the contract set, and the snagging visit at the end. The hands are ours, the handwriting is ours.
A typical Bluebell engagement. Yours may not need every stage — most homes don't. The Tier 2 sketch covers Stage 1. The Tier 3 survey covers Stages 1–2. Tier 4 hand-holding picks up at Stage 5 if your installer needs a second pair of eyes.
How a Bluebell call works
Three things make the free 15 minutes feel like an hour. Here's how.
Address, the problem, a few photos of your boiler, radiators, utility bills. The more you send, the more we prepare.
Cost: nothing. Effort: 5 minutes.
By the time we're on the call, we've reviewed your photos, looked up the kit, and worked out what we'd want to ask. No introductory waffle.
15 min feels like 60.
You'll know what to do next, what to ignore, what to ask your plumber. If you want more, you pick a tier. If not, no awkwardness.
No upsell. Genuinely.
Why bluebell exists
Most homeowners get one of two bad options: hire a £1,200/day consultant who hands a glossy report to a contractor, or trust the installer who sells you whichever product they happen to fit. Neither is good engineering.
The old way
The Bluebell way
Who runs bluebell
Harshal Sankhe
Mechanical Engineer · Founder
I genuinely love homes. I love the physics of how heat moves through a wall, how water pressure drops through a pipe, how the sun hits a roof in February. I love that the engineering used on Thames Valley Police estates, on district heating networks, on solid-oxide fuel cell power plants — the same maths can lower your gas bill in Hounslow.
I also know times are hard. Bills are real. Climate change is real. We have to do everything we can to protect what we value, lower our carbon, and help our communities adapt without being sold the wrong product by the loudest installer.
That's why bluebell starts with a free 15 minutes. If I can help in fifteen minutes, brilliant — you go and do it. If you want more, the prices are on this page. No day rates, no retainers, no quietly favoured manufacturer.
Twenty years on UK sites, an MSc from Cranfield self-funded, a clean-energy company in the background — the same engineering discipline that designs a 600–850 °C fuel cell stack, scaled down to your boiler cupboard. With your plumber, not without them.
Tech-agnostic by design
No commercial relationship with any manufacturer. No commission, no kickback, no preferred installer. When we recommend a heat pump, a boiler, a battery or a smart valve, it's because the maths says so for your house.
For commercial work
Defects investigation reports, options appraisals, M&E scope documents, compliance assessments (HTM 04-01, HSG274, CIBSE, BS 8558). Care home and healthcare estates speciality. Independent. Mechanically led.
Independent root-cause investigation. Cause separated from trigger. Liability allocated cleanly.
Three costed options, the engineering reasoning behind each, the recommendation.
HTM 04-01 Part D, HSG274 Part 2 Legionella, CIBSE Guide A&C, Part L 2021.
Stages 0, 1, 4 and 6 — where independent M&E judgement reduces project risk most.
News & views
A small library of articles, scans, and hand-drawn explainers we've found genuinely useful. Some by us, some by others — credited and linked. We learn in public.
Foundations · 5 min read
Big consultancies sell digital twins for thousands. We strip the term back to its useful core: a live picture of your house that helps you spend less on energy. Plus what we steal from open-source and what we don't.
Read article →From the press · scan
Valeria Ferrando (IES) on the difference between BIM and a digital twin, and why the live model wins. Full scan with our annotations on what applies to a single home.
Read article →Heat pumps · 7 min read
Flow temperature. Radiator output. Hot water demand. Insulation. Get these right and a heat pump pays back. Get them wrong and it's a £15,000 mistake. The plain-English version.
Read article →Solar & battery · 6 min read
Tariff structure changes everything. Octopus Agile, Cosy, Go. We work the numbers on three real Bluebell calls — names redacted, photos and bills shared with permission.
Read article →Older homes · 8 min read
The order matters more than the brand. The fabric of a 1950s house is the cheapest place to find £400 a year. Heat pumps love a well-insulated home. Sequencing is everything.
Read article →Smart homes · 6 min read
A smart thermostat doesn't fix a dumb heating curve. We open up what weather compensation actually does, with screenshots from a real Bluebell setup — and the £180/year saving it found.
Read article →More coming as we write them. The reading room is built to grow.