Window U value regulations for replacements in 2026
Replacing windows in 2026? The legal limit is a maximum U-value, not a target. Here is what Part L asks of a replacement, where the new-build rules differ and when to go further.
Installing Windows in Cold Weather: What 5 °C Changes
Timber frames cope with frost. The foam, tapes and sealants around them are what struggle below 5 °C. Here is what a careful fitter changes on a winter job.
Timber Windows Coastal Guide: Salt, Damp and Detailing
On a seafront elevation the timber is rarely the first thing to go. A practical guide to specifying coastal timber windows: stainless grades, trickle vents, coatings and sealed units.
Draughty Windows: Find the Leak, Choose the Fix
Most cold air arrives past the frame, not through the glass. How to locate the real leak in a timber window, what each fix costs you in effort, and when to stop spending.
Timber Window Installation: What Happens on Site
What actually happens when timber windows go in: how long the opening stays open, who makes good the plaster, where the perimeter seal fails, and why two fitting quotes rarely match.
Timber Patio Doors: Sizes, U-Values, What to Specify
Standard sizes, Part L U-value limits, hardware weight classes, thresholds and Part F ventilation: a manufacturer's guide to specifying a large glazed timber door properly.
Scandinavian Windows: Why They Open Outward
Outward-opening, top-swing, alu-clad: the scandinavian window works differently to a British casement. What that actually changes, and when it earns its price.
Secondary Glazing vs Double Glazing for Period Homes
Secondary glazing vs double glazing in a period home: which passes planning, which beats street noise, and the front-versus-rear rule most guides miss entirely.
Dutch Windows: What They Are and Why They Look Like That
Why are Dutch windows so tall, so thick, and so uncurtained? A timber manufacturer explains the 17th-century logic, the leaning-house myth, and how the design meets UK rules.
Condensation Between Window Panes: Fixable or Not?
Mist trapped inside the glass means the sealed unit has failed. A joiner's take on what actually fixes it, what defogging really buys you, and the real cost.