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Composite windows (UK): A complete guide

Composite windows are a sophisticated blend of materials designed to offer superior performance compared to traditional window options. Also known as alu-clad windows due to their makeup of timber with aluminium-cladding, these windows combine the aesthetics and strength of timber with the durability and low-maintenance properties of aluminium. By integrating different materials, composite doors and windows deliver a high-performance product that can enhance both the functionality and appearance of a home.

Here, we provide you with a comprehensive understanding of alu-clad windows, from their construction to their benefits and versatility.

Commonly used materials in composite windows

Our window frame styles are available in two types of frame and two depth options; timber, and aluminium-clad timber.

Timber

Prized for its natural beauty and excellent insulating properties, timber offers a blend of traditional charm, energy efficiency, and – if sourced responsibly – environmental sustainability. All 21 Degrees windows and doors are made from FSC®certified Redwood timber. Modern timber finishes provide a warm, classic look that can complement various architectural styles. What’s more, they’re so durable that when asked whether composite or uPVC windows are the best choice, we’d recommend alu-clad timber composite windows for almost every project.

Aluminium

Renowned for its strength and durability, aluminium provides excellent structural integrity, is resistant to corrosion, and requires minimal upkeep. It offers sleek sightlines and can accommodate large glass panels, maximising views and natural light ingress. When combined with timber, aluminium composite windows offer structural integrity and a low-maintenance exterior. 

Enhancing performance and durability

The combination of materials in alu-clad windows enhances their overall performance and durability. The timber interior provides excellent insulation and aesthetic appeal, while the aluminium exterior protects against the elements and reduces the need for regular maintenance. This synergy results in windows that are not only robust and long-lasting, but also energy efficient.

Thermal insulation and energy efficiency

One of the key benefits of alu-clad windows is their superior thermal insulation properties. The timber component acts as a natural insulator, significantly reducing heat transfer between the inside and outside of your home. This means that your home stays warmer in the winter and cooler in the summer, helping to reduce energy consumption and lower utility bills. 

What’s more, all our windows are Argon-filled, triple-glazed, and have dual compression seals, offering low U values, comfort, thermal performance, and airtightness. Taking all these factors into consideration, 21 Degrees alu-clad windows are an excellent choice for those looking to enhance their home's energy efficiency.

Resistance to environmental stressors

We’re often asked ‘Are alu-clad windows suitable for different climates?’. Generally, yes – the aluminium exterior protects against most harsh weather conditions, while the timber interior provides excellent insulation, making them ideal for both hot and cold environments. 

Furthermore, composite materials are engineered to withstand various environmental stresses. The aluminium exterior provides a protective barrier that is resistant to warping, rotting, and – in most cases – corrosion. However, it’s important to note that aluminium cladding is unsuitable for coastal locations due to salt corrosion. 

All of this makes alu-clad wood composite windows a durable and reliable choice for most climates, ensuring that they maintain their performance and appearance over time. What’s more, for projects where re-painting is not possible or for commercial applications where windows won’t be correctly maintained, aluminium-clad windows and doors can be a preferred specification.

Versatility in architectural styles and designs

Composite windows offer unmatched versatility in terms of design and application. Whether you have a traditional, rustic home or a sleek, modern building, alu-clad windows can be tailored to match your architectural style. The combination of timber and aluminium allows for a wide range of finishes and colours, ensuring that your windows complement your overall design aesthetic. Our windows and doors are available in a selection of natural wood stains or the RAL classic range, and we offer a range of frame styles, glazing options, and hardware to ensure your windows are unique to your project.

Minimal upkeep compared to traditional materials

One of the standout benefits of composite windows is their low-maintenance requirements. Alu-clad windows only require occasional cleaning to maintain their appearance. This makes them an ideal choice for homeowners seeking the beauty of wood without the associated upkeep, such as repainting.

Even so, you may still ask ‘But can you paint composite windows, if you want to?’ and the answer is yes, though it’s usually not necessary due to the durable finishes available. If you do choose to paint them, it's important to use appropriate primers and paints designed for use on both timber and aluminium surfaces.

Alu-clad windows represent the best of both worlds, combining the natural beauty and insulation of timber with the durability and low maintenance of aluminium. They offer enhanced performance, energy efficiency, and versatility in design, making them an excellent choice for any home. Whether you are looking for the best composite windows in the UK or are seeking reliable composite window suppliers, understanding the benefits and features of these innovative windows will help you make an informed decision for your home.

By choosing alu-clad windows, you invest in a product that not only enhances the aesthetic appeal of your home but also contributes to energy savings and long-term durability.To find the right window type for your personal project and its requirements, get in touch with our composite windows and doors team.

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