Best Aluminium Windows UK: Cortizo, Schuco and Origin

Search for the best aluminium windows and you will find long lists of brand names with very little to separate them. The honest answer is that a handful of profile systems account for most premium aluminium windows fitted in the UK, and the right one depends on the look you want, the thermal target you need to hit and how the window will be used. This guide compares the three window ranges we supply and fit, Cortizo, Schuco and Origin, using the manufacturers' own published figures, and explains how to choose between them for your home.

What Makes an Aluminium Window "the Best"?

Every system on this list meets current Building Regulations when specified correctly, so the differences that matter are practical ones:

• Sightlines. How much frame you see around the glass. Slimmer frames give more glass and a more contemporary look; our slimline aluminium windows and doors page shows the narrowest options side by side.
• Thermal performance. Replacement windows in England must achieve a whole-window U-value of 1.4 W/m²K or a Window Energy Rating of band B, a rule in force since 15 June 2022. The best systems go well beyond it with triple glazing.
• Opening style. Outward casement, flush casement, hidden sash or inward-opening tilt and turn. The opening style shapes both the look and how you live with the window.
• Security. Look for PAS 24 testing, the standard referenced by Approved Document Q and by Secured by Design.
• Who makes and fits it. A strong profile system can be let down by poor fabrication or installation. Ask who cuts, assembles and fits the window, and whether the installation is FENSA registered.

The Systems Compared

Cortizo: The Best All-Rounder

Cortizo is a Spanish aluminium systems company, and its Cor 70 Hidden Sash is the window we specify most often. The opening sash sits concealed behind the outer frame, so opening and fixed lights look identical from outside, with a visible section of 66mm. Cortizo publishes a whole-window U-value from 0.84 W/m²K for the system, and the same frame can be configured as a casement or an inward-opening tilt and turn. It is tested to PAS 24.

We manufacture and fabricate Cortizo windows in our own Uxbridge workshop from genuine Cortizo profile, then install them with our own team, so one company is responsible from survey to handover. For most homes that want slim, uniform aluminium windows with strong thermal performance, Cortizo is where we start. Our Cortizo aluminium windows review goes into the range in more detail, and the Cortizo windows page has the full specification.

Schuco: Premium German Engineering

Schuco is the German systems house many architects default to, and its AWS 70 range covers three distinct windows:

• AWS 70.HI, the mainstream casement, with a 70mm frame depth, frame U-values (Uf) from 1.6 W/m²K and face widths of 105mm outward opening or 117mm inward opening.
• AWS 70 SC Slimline, a narrower 63.5mm profile for contemporary elevations where a lighter frame matters.
• AWS 70 Tilt-and-Turn, the inward-opening version, which suits upper floors and windows you want to clean from inside.

Schuco systems can be specified to PAS 24 where Approved Document Q applies. We fabricate Schuco in-house in Uxbridge, the same as Cortizo. Schuco tends to suit projects where an architect has specified it by name, or where the buyer wants the depth of engineering documentation Schuco is known for. Our Schuco aluminium windows review explains where it is the right answer and where it is not, and the Schuco windows page lists the configurations.

Origin: British-Made Flush Casements

Origin manufactures its windows in its own factory in High Wycombe, and we supply and install them as an Origin Approved Partner. The range is built around flush casements:

• OW-70 Slimline, with sightlines of 65mm where frame meets sash and the sash sitting flush with the frame on the outside face. It is tested to PAS 24:2022 and Secured by Design.
• OW-80 Premium, flush on both faces for Origin's clean Gallery look, with glass units up to 44mm and a best U-value of 0.9 W/m²K, or 0.8 W/m²K with the optional Aerogel upgrade. Also PAS 24:2022 and Secured by Design.
• Origin tilt and turn, in short-leg and long-leg frames, from 1.4 W/m²K double glazed down to 0.83 W/m²K triple glazed, tested to PAS 24:2022.

Origin gives up to a 20-year guarantee on parts (Origin's terms apply). It is a strong choice for buyers who want a British-made flush casement and a single supplier for windows, doors and bifolds. See our Origin windows page for sizes and configurations.

Side-by-Side Summary

A note on the numbers: manufacturers publish different measures (a whole-window Uw against a frame-only Uf, or a visible section against a sightline), so a straight comparison of figures can mislead. We confirm the exact performance of the specification we quote for your openings.

Which Is Best for Your Home?

Choose Cortizo if you want the cleanest, most uniform modern look, strong thermal performance and a window made and fitted by one team. It is our default recommendation for full-house replacements and new extensions.

Choose Schuco if your architect has specified it, if you want the AWS 70 SC Slimline profile, or if you prefer a long-established German system with deep technical support.

Choose Origin if you want a flush casement with Secured by Design certification, or if you are also choosing Origin bifold or sliding doors and want everything from one British manufacturer.

For period properties and conservation areas the decision changes again, because planning officers look closely at proportions and glazing bars. Our guide to the best aluminium windows for conservation areas covers that case.

Not sure which system suits your home? Request a free quote or call 0800 861 1450 and we will recommend the right aluminium window for your property, with a written quote and no obligation.

What About uPVC?

Aluminium is not always the right answer. If budget is the deciding factor, a premium uPVC system such as Rehau TOTAL70 gives excellent thermal performance for less. Our aluminium vs uPVC windows comparison sets out the trade-offs honestly, and our aluminium windows cost guide explains what drives the price of each system.

Our Recommendation

There is no single best aluminium window, only the best system for a given house. We fit all three ranges, so we have no reason to push one over another. We manufacture and fabricate Cortizo and Schuco windows in Uxbridge and supply and install Origin as an Approved Partner, across Buckinghamshire, Berkshire, Hertfordshire, Surrey, Hampshire, Oxfordshire and West London. Every installation is FENSA registered and backed by our 10-year CPA insurance-backed guarantee. Request a free quotation and we will recommend the system that fits your property, your thermal target and the way you use each room.

Frequently Asked Questions

What are the best aluminium windows in the UK?

For most homes, Cortizo, Schuco and Origin sit at the top of the market. Cortizo's Cor 70 Hidden Sash gives the most uniform modern look with a published Uw from 0.84 W/m²K. Schuco's AWS 70 range suits architect-specified projects. Origin's OW-70 and OW-80 flush casements are made in High Wycombe and carry PAS 24:2022 and Secured by Design. The best choice depends on the look, thermal target and opening style you need.

Are aluminium windows better than uPVC?

Aluminium gives slimmer frames, more glass and a longer service life, and it can be powder coated in almost any RAL colour. Premium uPVC costs less and performs very well thermally. Both meet Building Regulations when specified correctly. If slim sightlines and a contemporary look matter most, aluminium is usually the better fit.

Which aluminium windows are the most energy efficient?

Among the systems we fit, the highest published figures are Cortizo's Cor 70 Hidden Sash at a Uw from 0.84 W/m²K and Origin's OW-80 at 0.8 W/m²K with the Aerogel upgrade. Both need triple glazing to reach those figures. Every system here meets the 1.4 W/m²K requirement for replacement windows in England.

Can I get aluminium tilt and turn windows?

Yes. Cortizo, Schuco and Origin all offer an inward-opening tilt and turn version. It tilts in at the top for secure ventilation and turns fully open on its side hinges so you can clean the outside pane from indoors, which is why it is popular for upper floors. Our tilt and turn windows guide explains how they work.

Do you manufacture aluminium windows yourselves?

We manufacture and fabricate Cortizo and Schuco windows in our own Uxbridge workshop from the brands' genuine profile, and fit them with our own installation team. Origin windows are made by Origin in High Wycombe, and we supply and install them as an Approved Partner. Every installation is FENSA registered with a 10-year CPA insurance-backed guarantee.