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Windows, doors & conservatories - London, Surrey, Kent & surrounding areas
Osborn Glass, 33/34 High Street,
South Norwood, London, SE25 6HA
Call Osborn Glass, London Double Glazing

Call Osborn Glass, London Double Glazing 020 8683 8406

Home » Windows » Casement Window Installer » Aluminium Casement Windows

Outstanding aesthetics and thermal performance

If you’re refurbishing you home windows, or you’re kitting out a commercial build, aluminium casements offer great versatility. Their energy rating and green guide ratings are both at the top end, meaning you’re spending less on the bills, and doing your bit towards saving our planet.

The brand of casements we instal for you is Kitemarked – including PAS24:2016 – which in translation means excellent security and weather performance. In short, they keep all you’re valuable heat in, and unwanted weather and intruders out.

Available in single or dual colours

Aluminium isn’t known for hosting a variety of colours; the quality powdered coat comes suits modern applications most. But, if you’d like a less common colour, or to layer up with dual colour, we can have that arranged too.

Alitherm 800 Flush Casement

Providing a ‘French mullion’ option for contemporary properties, the high-quality Alitherm 800 Flush Casement window delivers outstanding aesthetics and thermal performance.

Delivering an ‘A’ window energy rating and a U-value of just 1.3W/m²K (dependant on the sealed unit used), Alitherm 800 windows are suitable for a wide range of applications, including both residential and light commercial new build and refurbishment projects.

The high-performance Alitherm 800 system offers a range of options, including side-hung, top-hung and the completely new French casement variants, as well as a number of the outer frames, sash and bead options.

• BRE Green Guide A+
• Window Energy Rating A
• U Values up to 1.3 W/m²K (depending on system and glass unit)
• Kitemarked – which includes PAS24:2016 security and high weather performance.

Smart aluminium windows and doors

For 40 years, smart has grown into one of the UK’s leading suppliers of aluminium glazing systems and bespoke aluminium extrusions. Their designs and technical expertise are second to none, and they live up to their reputation as industry innovators.

We have helped to instal smart’s products in a host of new-build and refurbishment projects in and around South London, UK. Our clients have ranged from architectural, commercial, public, new-build and retail applications.

You’ll find smart HQ in Based in Yatton, North Somerset. Their 60,000m² purpose-built premises is quite something. It hosts state-of-the-art extrusion, finishing, warehousing and distribution facilities. We’re lucky to be one of their trusted partners and installers.


Sheerline offer a range of window, door, bi-fold and lantern systems; creating warm, slim and ultra-secure products, designed for discerning homeowners who aren’t willing to compromise. Built around our innovative Thermlock® multi-chamber thermal break, Sheerline windows use a patented construction method that creates the most beautiful, high-quality finish possible. Stylish, safe and sustainable – and offered with unbeatable service levels – Sheerline is the right choice for homeowners, installers and fabricators.

Call Osborn Glass, London Double Glazing 020 8683 8406

Window and door installations in South London and beyond

Since 1966 we’ve been supplying and installing the finest windows, doors, conservatories and more to people just like you. Most of our customers are located in London, Kent and Surrey, but we are happy to supply and install our windows right across the Home Counties, East Anglia and the Southeast. Get in touch with us today with any questions, concerns or queries and we’ll be happy to help.

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