The Invisible Leak: Why Your Home is Bleeding Heat The signs are familiar. A persistent chill in the hallway, long after the heating has stopped. A room that never quite reaches temperature, even with modern double glazing. The thermostat rises. The warmth does not stay. Conventional wisdom places the blame on the glazing. Triple panes, … Continued
The Myth of the Pane: Why U‑Values Aren’t What You Think For decades, homeowners have been led to believe that window performance begins and ends with glass. Add another pane, they’re told — double it, or triple it — and efficiency will follow. It’s a simple message, and an incomplete one. In reality, energy performance … Continued
Winter Is Approaching — Are Your Windows Up to Standard? As the days shorten and temperatures drop, the ambient warmth within your home begins to slip away — often more rapidly than expected. You turn up the thermostat. You reach for another layer. Yet the cold persists, subtly but insistently. In most cases, it isn’t … Continued
The Silent Culprit Behind Rising Energy Bills London’s most distinguished homes — with their soaring ceilings, intricate cornices, and elegant sash windows — were designed for grandeur, not thermal performance. Yet behind their architectural beauty lies a persistent and largely invisible inefficiency: the steady loss of heat through outdated glazing. Each winter, the symptoms become … Continued
The Truth Behind the Badge The Passive House standard has become something of a byword for building excellence—particularly when it comes to windows. Certified systems are marketed as the pinnacle of performance: energy-efficient, expertly engineered, and future-ready. But a fundamental question remains—does certification automatically guarantee real-world benefit? At Sash Windows London, we recognise the scientific … Continued
Why Frame Material Matters More Than Most Realise When discussions turn to energy-efficient windows, attention typically falls on the glazing — double, triple, solar control, low-E coatings. But glass is only part of the equation. The true determinant of long-term performance lies not in what you look through, but in what holds it together. The … Continued
The Invisible Cost of Charm Sash windows are undeniably beautiful. They embody heritage, craftsmanship, and architectural continuity — elements no modern substitute can authentically reproduce. Yet beneath this character lies a quiet liability: poor performance. A single-glazed, unsealed sash window can be responsible for up to 30% of a property’s total heat loss during winter. … Continued
The Unseen Saboteur: Where Performance Actually Fails You can specify the highest-rated triple-glazed window, select thermally broken frames, even invest in Passivhaus-certified units— and still suffer avoidable heat loss. Not because of the product. Not because of the glazing. But because of what happens at the perimeter. Performance often fails not in the window itself, … Continued
