As the UK prepares to mandate solar power in new homes, a race is under way to make glass itself a source of clean energy, and to do it without sacrificing the view
The glass in the facade of a modern office block does three things: it keeps the rain out, lets the light in, and, if the building’s energy performance consultant is doing their job, loses as little heat as possible. For most of the past century, that has been considered sufficient. A generation of researchers, and a growing cohort of manufacturers, now believe it should do considerably more.
Building-integrated photovoltaic glazing — BIPV, in the trade’s useful compression — is the technology at the heart of this ambition. The proposition is straightforward: replace the inert glass in a building’s windows, facades, and skylights with glass that converts sunlight into electricity. The execution, as the industry is discovering, is considerably less so.
The basic commercial case has been articulated for years. The UK Green Building Council has noted that while solar PV glass costs approximately twice the price of conventional glazing, when incorporated into a curtain walling system it represents a small fraction of total build cost, with payback periods of between five and 20 years and revenue potential stretching over three decades. The challenge has always been persuading a risk-averse construction sector to move first.
That calculus is about to change, and the agent of change is Whitehall. The Future Homes Standard, confirmed by the Department for Energy Security and Net Zero in 2025, mandates that new residential buildings install solar PV covering the equivalent of 40% of the ground floor area as a default requirement, with full compliance required from March 2028. Where rooftop panels cannot be accommodated, due to shading, orientation, or design constraints, facade-integrated BIPV glazing provides an architecturally coherent alternative route to compliance. For commercial developers constructing high-rise schemes above 18 metres, where the rooftop mandate does not apply, the same technology becomes a voluntary means of meeting net-zero ambitions.
The timing is propitious. The global BIPV market was valued at $23.41 billion in 2025 and is projected to expand to $85.9 billion by 2034, growing at a compound annual rate approaching 15%. Europe held a 41.8% share of that market in 2025 — a dominance driven partly by the continent’s stringent building energy codes and partly by the architectural preferences of a region where glass-dominant facades have long been fashionable. Within that broader market, the glazing-specific segment is growing faster still: BIPV glass alone is forecast to reach $24.1 billion globally by 2035, up from $4.6 billion today.
Yet it is the next generation of the technology — rather than today’s commercially available products — that has investors and researchers most animated. Current BIPV glass products, including offerings from NSG Group’s Pilkington subsidiary and UK-based Polysolar, use crystalline silicon cells embedded between glass panes. The transparency is achieved by varying the spacing and density of the cells. The result is functional, warranted for 25 years, and increasingly specified for commercial projects. But it remains, in the eyes of the research community, an interim solution.
The technology attracting serious scientific capital is perovskite-based semi-transparent solar glass. Perovskite solar cells — named for their characteristic crystal structure — use hybrid organic-inorganic compounds that can be applied to glass as an ultra-thin coating through solution-based processes including spin-coating and inkjet printing. The implications for manufacturing economics are significant: unlike silicon-based photovoltaics, which require energy-intensive high-temperature production, perovskite layers can in principle be deposited at lower cost and with greater flexibility in terms of transparency and colour.
The efficiency numbers are beginning to catch up with the promise. Researchers at the ARC Centre of Excellence in Exciton Science have developed solar window prototypes achieving 17% power-conversion efficiency while remaining visually transparent — approaching the 20% efficiency of conventional opaque rooftop panels. Oxford PV, the Oxford University spin-out co-founded specifically to commercialise perovskite technology for glass-clad buildings, has demonstrated that once integrated into a building facade, the technology is “capable of powering much of the building’s lighting and IT infrastructure.”
The obstacles are real and should not be minimised. Perovskite stability under prolonged UV exposure and the toxicity concerns associated with lead-based formulations remain active research problems. The global perovskite solar panel market, currently valued at $271 million, is projected to reach only $488 million by 2034. These are not the numbers of a technology on the cusp of mass adoption.
But in an industry accustomed to decade-long product cycles, the trajectory matters as much as the destination. For UK fenestration manufacturers prepared to move earlier than their peers — establishing supply chain relationships, investing in technical competence, and engaging with the research ecosystem — the window of competitive advantage is open. The question is whether they will look through it.
