Window Profile Systems Comparison Guide | Window Fitters

How to Choose the Right Window Profile System (Deceuninck vs Liniar vs Rehau vs Profile 22)

When homeowners request quotes for new uPVC windows, they often focus on the glass and the double-glazing installer. However, the quality, durability, and thermal performance of a window are largely determined by its profile system - the extruded uPVC frame structure. In the UK trade, four major brands dominate the market: Deceuninck, Liniar, Rehau, and Profile 22. This guide compares these leading systems to help you choose the right frame for your property.

Expert Reviewed by Marian Gheorghe, Head Window Fitter - Last reviewed: July 2026

What is a Window Profile?

A window profile is the extruded plastic section that forms the window frame and sash. Rather than being solid plastic, modern profiles are hollow and divided into multiple internal chambers. These chambers serve two critical functions:

1. Thermal Insulation: The chambers trap pockets of still air, which acts as a barrier to slow down heat transfer, lowering U-values.
2. Structural Strength: The internal walls provide rigidity, and the central chambers are often reinforced with galvanized steel or composite materials to prevent the frame from flexing under wind loads or forced-entry attacks.

Direct Comparison: The Big Four UK Profile Systems

Detailed Brand Analysis

1. Profile 22 (Optima Range)

Profile 22 is one of the most established and trusted manufacturers of PVC-U window and door systems in the UK. Fabricators and installers respect the Optima system for several key reasons:

• Installation Consistency: The profile tolerances are precise, ensuring sashes seal perfectly and locks align without sticking.
• Security: The frames feature localized wall thickening around lock keeps, allowing fixing screws to bite deeper and resist crowbar attacks.
• Aesthetics: The Profile 22 flush sash replicates traditional timber profiles, making it popular in conservation zones.

2. Deceuninck (2500 System)

Deceuninck is a global leader in uPVC extrusion, and their 2500 chamfered profile is a staple of the UK window market. It is highly valued for:

• Affordability: Offers excellent value for whole-house replacement projects.
• Colour Availability: Deceuninck holds the largest stock of color foil laminates in the UK, offering rapid lead times for Anthracite Grey (RAL 7016), Black, and Cream foils.

3. Liniar

Liniar was designed from scratch in 2007 to be the most energy-efficient profile system on the UK market. Its highlights include:

• No Steel Reinforcement Needed: Rather than using steel ribs (which conduct cold), Liniar uses internal webbing and structural plastic reinforcement, achieving U-values as low as 1.2 Uw with standard double glazing.
• Fully Recyclable: Formulated with 100% lead-free uPVC.

4. Rehau (Total 70 System)

Rehau is a premium German engineering brand, and their Total 70 system is regarded as a heavy-duty option. Rehau is selected for:

• Gloss Finish: Rehau profiles have a unique, ultra-smooth surface finish that sheds dirt easily and remains bright white for decades.
• Rigidity: Heavily reinforced with galvanized steel, making it the preferred choice for commercial developments and large sashes.

5. Norrsken / morsken (High-Performance Timber & Alu-Clad)

For high-spec eco builds, Passivhaus developments, and architectural refurbishments where wood warmth meets exterior aluminium protection, we source high-performance timber and alu-clad systems such as Norrsken (frequently queried as "morsken"):

• Passivhaus Performance: Triple-glazed alu-clad systems achieve exceptionally low whole-window (Uw) U-values from 0.64 to 0.94 W/m²K.
• Alu-Clad Durability: Engineered timber core provides natural thermal insulation indoors, while exterior powder-coated aluminium cladding shields against extreme weather without requiring repainting.
• Market Sourcing: We can source any system on the market-focusing on quality, structural integrity, and long-term performance.

About the Author: Marian Gheorghe

Head Window Fitter & Active Director, Window Fitters Ltd

Marian Gheorghe is the Head Window Fitter and Director of Window Fitters Ltd. He has spent over 15 years fabricating and fitting Profile 22, Deceuninck, Liniar, and Rehau uPVC window systems for domestic and commercial clients across London.

Connect on LinkedIn → Expert Reviewed: July 2026

Profile Comparison FAQs

Can I mix different profile brands in the same house?

We advise against it. Different brands use slightly different shades of white, and their frame bevels and profiles vary. To maintain visual consistency, use the same system throughout the property.

Which profile system is the most secure?

When fitted with PAS 24 locking hardware, steel reinforcements, and internal glazing beads, all four brands provide equivalent resistance to forced entry, meeting Approved Document Q requirements.

Do uPVC profiles turn yellow over time?

No. Modern uPVC profiles from major brands are formulated with titanium dioxide stabilizers to resist UV radiation. Yellowing is only an issue with cheap, unbranded import profiles.