London's Tewke is betting that solving the neutral wire problem—a frustration most homeowners don't know they have—could unlock energy automation for millions
Most UK homes hide an electrical quirk that the smart home industry has been working around for years. Ask any installer: there's no neutral wire at the light switch. Not in older properties, certainly. But often not in newer ones either.
That small wiring detail has spawned an entire sub-category of workarounds—dimmers that pulse power, modules that tuck into ceiling roses, wireless switches that abandon the wall box entirely. None have cracked the code on what homeowners actually seem to want: a proper touchscreen controller, mounted where the old light switch used to be, that just works.
London-based climate tech startup Tewke thinks it's found the answer. The company announced this week that it closed a £1.5 million funding round in February 2026, bringing in JamJar Investments, Cur8 Capital, Energy Mix Ventures, and Project Ventures. The investor list also includes Vlad Yatsenko—Revolut's co-founder and CTO—lending some fintech credibility to what is essentially a hardware play in the messy, capital-intensive world of smart home devices.
For a company that shipped its flagship product barely a year ago, the backing suggests something more than incremental improvement is at stake here.
An Invisible Engineering Challenge
The Tap smart switch—Tewke's main product—looks unremarkable at first glance. It's a sleek touchscreen panel that fits into a standard UK single-gang wall box. You could mistake it for any number of competitors flooding the market.
What's different is underneath. The device works in homes wired without neutral wires at the switch location, a configuration that covers most British properties built before the 1990s and, frustratingly, plenty built since. Traditional smart switches need that neutral connection to power their electronics continuously. Without it, they're inert plastic.
Homeowners typically face an unpleasant choice: pay an electrician hundreds or thousands of pounds to rewire the house, or give up on in-wall smart controls altogether. Tewke claims Tap is the first touchscreen light switch designed to function either way—neutral or no neutral.
The device controls up to three dimmable lighting channels at 100 watts each, for a 300-watt total. In no-neutral installations, it requires compatible dimmable LED or incandescent loads. (The company provides compatibility lists, because not all LEDs behave the same when you're pulling power through the load itself.) It's not magic. Just careful electrical engineering married to software that knows how to manage tight power budgets.
Whether that combination holds up at scale remains to be seen.
The Bigger Bet: Energy, Not Lighting
Founder and CEO Piers Daniell didn't set out to build a better dimmer switch. His background is in telecom—he previously built Fluidata, a business connectivity firm. The Tap device, with its 3.92-inch touchscreen running at 1080×1240 resolution, feels more like a small computer that happens to control lights.
It is, in fact, exactly that. A quad-core processor, 2GB of RAM, 16GB of storage. Doppler radar motion sensing, temperature, humidity, air pressure, ambient light sensors. VOC sensors and calculated CO2 readings. There's even a microphone for a planned voice assistant called TewkeAI, powered by Google Gemini and expected in the first half of this year.
The hardware is manufactured and hand-assembled in the UK—a decision Daniell tied to quality control and the company's B Corp certification, achieved in September 2025 with a B Impact Score of 93.8. That's well above the threshold and suggests the sustainability commitments go deeper than marketing veneer. Then again, B Corp status doesn't guarantee commercial success.
What Tewke is really building is an energy platform disguised as a light switch. The touchscreen displays real-time tariff pricing. The company is working with Octopus Energy to surface grid insights directly on the device. Smart meter integration and historical usage data are slated for early 2026, with automations that respond to carbon intensity and variable pricing to follow shortly after.
The pitch is straightforward enough: shift appliance usage to periods when renewable energy is abundant and cheap. Then make that behavior automatic so people don't have to think about it.
Whether British households are ready to let a wall switch manage their washing machines is another question entirely.
Building in Public, Sort Of
COO and co-founder Rowan Dixon, a 2020 graduate of Imperial College London's Design Engineering program, led product development. The company debuted Tap at CES 2025 following an October 2024 launch event in London and a Red Dot Award for Design Concept earlier that year. Awards, of course, don't pay the bills.
More telling, perhaps: fifty-four Tap units are installed in Daniell's own Warwickshire property, a renovation project that aired on Channel 4's Grand Designs in late 2025. Developer Norse Homes is installing the device in every room of three new UK properties for live trials, providing performance data in real-world conditions. That was announced in January.
Retail pricing sits at £389 for the full unit—not cheap, particularly when compared to £40 smart switches from competitors. Early adopters who signed up for the Tap Preview program can access it for £7.99 monthly over 12 months, plus a £99 setup fee. Distribution includes direct-to-consumer sales and trade channels like City Electrical Factors.
Thread connectivity and Matter-readiness via over-the-air update are baked in, though buyers should confirm certification status at purchase. Smart-plug integration went live in May 2025. Two additional products are coming: the £209 "One" capacitive touch switch in March 2026, and the £449 "Sonar" four-gang model with integrated speaker.
Each new product widens the addressable market. Each also increases complexity and support burden.
A Crowded Field, A Narrow Opening
Tewke isn't alone in tackling the no-neutral problem. Lutron's Caséta dimmers work without neutral wires, as do GE Cync switches and Lightwave's UK-focused offerings. Aqara's Zigbee devices handle it, and Shelly modules offer DIY solutions for the technically inclined. What none of them offer is a high-resolution touchscreen, significant onboard compute, and the sensor array Tap packages into one device.
Whether that combination justifies the premium pricing depends entirely on execution. Energy automation requires more than slick hardware. It needs reliable software, useful automations, seamless integration with energy providers, and enough user trust to hand over decision-making to an algorithm.
Tewke's November 2024 seed round of €3.1 million—plus grants from the UK Net Zero Pre-Commercialisation Support Fund and Housing Digital Innovation Award—gave the company initial runway. This new £1.5 million extends it. Chairman Sir James Wates, former head of construction giant Wates Group, brings industry connections. Participation in Google's AI for Energy Accelerator adds technical credibility.
The timing might be right. Variable energy tariffs are becoming more common in the UK as grid operators seek demand flexibility. Decarbonization targets are pushing renewable deployment, creating greater price volatility and opportunity for load shifting. Consumers are increasingly aware of energy costs, if not always equipped to act on that awareness.
Whether a £389 light switch becomes the interface for that behavioral shift is the £1.5 million question. Investors, at least for now, seem willing to find out.
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Correction: An earlier version of this article misstated the Thread connectivity status. It has been clarified that buyers should confirm Matter certification status at the time of purchase.
