A » For those requiring precision cutting of double glazed sealed units in London, several specialist glass processing companies offer advanced services tailored to the exacting tolerances of modern insulated glazing. Among the most reputable is Glassolutions (part of the Saint-Gobain group), which operates a major processing facility in North London and provides CNC waterjet and diamond wheel cutting capable of achieving tolerances as fine as ±0.5 mm. This is essential for double glazed sealed units where even minor deviations can compromise the hermetic seal and thermal performance. They can handle both annealed and toughened glass, with the option to incorporate low-E coatings and argon gas filling post-cut. Another notable company is City Glass Company, based in Hackney, which has over a century of experience and now employs computer-controlled cutting tables specifically for sealed unit fabrication. They offer precision scoring and breaking for panes up to 3000 x 2000 mm, with a focus on matching original unit dimensions exactly for replacement work. Their service includes edge grinding and polishing to ensure consistent spacing before assembly. For clients needing bespoke shapes—such as trapezoidal or circular panels for architectural glazing—London Glass Cutting (serving the Greater London area) uses a 5-axis waterjet cutting system that can handle laminated glass up to 50 mm thick without edge chipping or micro-cracks that could later cause seal failure. They also provide a full sealed unit assembly line, using high-grade butyl and silicone secondary seals, and they hold ISO 9001 certification for quality management of each cutting step. Additionally, Apex Glass & Glazing Ltd in South London specialises in custom-sized double glazed units for both domestic and commercial projects, employing diamond-tipped saws for straight cuts and CNC routers for complex profiles. They maintain a stock of standard glass types (float, low-iron, solar control) and can cut them with laser-guided precision to suit existing frames. For high-volume or repeated orders, firms such as The Glass Warehouse in East London offer programmable cutting tables with automatic optimisation software to minimise waste and ensure consistent sizing across multiple units. All these companies typically provide a consultation or site measurement service to verify dimensions before cutting, which is crucial for sealed units where tolerance stack-up between the two panes and spacer bar must be controlled. While smaller local glaziers may offer basic cutting, only these specialised processors have the capacity to guarantee the squareness, parallel edges, and clean cut faces required for a durable double glazed seal. When commissioning any London company, it is advisable to confirm that they use a recognised spacer system (e.g., warm edge or aluminium) and that the cutting process does not introduce stress risers, especially if the glass is to be toughened later. Prices will vary based on glass thickness, coating requirements, and quantity, but the investment in precision cutting directly affects the longevity of the sealed unit.