A new report from RE:UK has thrown a spotlight on the scale of rooftop solar capacity being left untapped across the UK, warning that vast areas of viable roof space on homes, warehouses and commercial buildings remain without panels despite the technology's falling costs and improving returns. The findings, covered by Planning, Building & Construction Today, add to a growing body of evidence suggesting that the UK's approach to solar deployment is failing to capitalise on some of the most readily available and least contentious space for renewable generation. Rooftop solar has long been championed by industry figures as a comparatively straightforward route to boosting the UK's clean power capacity, sidestepping many of the land-use disputes and planning battles that have dogged ground-mounted solar farms and other large-scale renewable projects. Unlike utility-scale developments, which often require agricultural land and can face fierce local opposition, rooftops on existing buildings represent space that is already developed and, in many cases, sitting idle in terms of energy generation potential. The report's emphasis on "missed opportunities" points to a persistent gap between the UK's solar ambitions and what is actually being installed on the ground. This is not a new concern for the sector; commentators have repeatedly argued that commercial and industrial rooftops, in particular, offer some of the best returns on investment for solar given their large surface areas and daytime energy consumption patterns that align well with solar generation. Warehouses, distribution centres and retail parks are frequently cited as prime candidates, yet uptake across these building types has historically lagged behind expectations. For households, rooftop solar continues to be viewed as a key tool in reducing energy bills and easing pressure on the wider grid, particularly as electricity demand is expected to rise with the continued rollout of electric vehicles and heat pumps. Every domestic or commercial roof fitted with panels represents a small but meaningful contribution to decentralised generation, reducing reliance on the transmission network and helping to smooth demand at a local level. The publication of this report will likely renew calls for stronger policy incentives, streamlined planning processes and clearer building regulations to encourage greater uptake of rooftop solar across both new-build and existing stock. With the UK government committed to decarbonising the power sector and expanding renewable capacity as part of its broader net zero strategy, the built environment is increasingly seen as an underused asset in that effort. As scrutiny of the UK's renewable energy strategy continues, reports such as this are likely to keep pressure on policymakers, developers and building owners alike to reconsider how existing infrastructure can be better harnessed, rather than relying solely on new large-scale renewable developments to meet the country's climate targets.