Aluminium vs steel windows

When choosing windows for your home or commercial property, the decision between aluminium and steel will shape not only the look of your building, but also your project’s budget and the longevity, performance and sustainability of your windows.

As experts in installing replacement windows for thousands of properties throughout Sussex, we explain the difference between these robust materials to help you make the right choice for your project, whether for a domestic or business setting.

The attributes of aluminium vs steel

While aluminium and steel windows share a similar aesthetic – both materials offer slim, elegant sightlines – they each have distinct attributes that will inform your choice depending on the context and priorities of your project.

Aluminium windows

Strength and aesthetics

Aluminium is incredibility strong, yet lightweight. This means that it is highly adaptable when it comes to form and, because it’s light, it can be used to create expansive areas of glazing.

It can be moulded into a variety of profiles and its slim, lightweight and malleable nature allows it to be easily formed into a variety of shapes and sizes.

For example, our range of aluminium windows are available in a ‘flush sash’ style, which gives a sleek, contemporary look, or with sculpted details and Georgian bars to suit traditional properties.

Security

Despite their lightweight nature and slim profile, aluminium windows offer unrivalled security, meeting the PAS24 security accreditation.

Advanced manufacturing methods also strengthen the frame corners, securing both the frames and the glazing.

Thermal efficiency

Aluminium windows are manufactured with the latest thermal break technology, which gives them excellent thermal insulation and minimises condensation.

All opening windows also include double rebates and in-built weather seals, to prevent draughts and water ingress.

Maintenance

Renowned for its longevity, aluminium doesn’t rust or corrode. It is highly durable in all weather conditions.

Aluminium is very low maintenance, especially when it has been powder coated and finished in the chosen colour. It requires only occasional, light cleaning.

Colour choice

Colour selection is a key part of the design of your project.

Available in the full spectrum of RAL colours and a selection of anodised finishes, with aluminium windows the choice of colour and finish is virtually limitless.

While the current trend is for black aluminium window frames, you can actually choose from thousands of different colours.

Sustainability

Aluminium is not only abundantly available, is one of the most recyclable materials on the planet, making it a highly sustainable resource.

According to the International Aluminium Institute, the recycling process uses only 5% of the energy required to make new aluminium.

Cost

Aluminium is a significantly more affordable option than steel – costing usually four to five times less.

Aluminium emulating tradition

For this period Sussex property, aluminium windows not only achieve the desired traditional aesthetic, they provide long-term energy efficiency, low-maintenance and longevity.

Steel Windows

Strength and aesthetics

Steel, by its nature, is incredibly strong. When used for windows, this strength allows for enormous panes of glass and ultra-slim profiles. Think The Shard or the Eden Project’s domes.

Steel lends itself to industrial-style architecture and period or listed properties where its use may be stipulated as a like-for-like replacement.

Modern steel windows can also be styled with precision and creativity, but this is a more labour-intensive process as you’d expect from such a robust material.

Security

The sheer strength of steel makes it a very secure material for windows, as it is very difficult to bend or damage.

Steel windows can be fitted with multi-point locking systems and glazing bars for increased security.

Thermal efficiency

Not all steel windows include a thermal break within their frames. This reduces thermal insulation and can cause condensation to form.

However, most modern steel windows do meet the required standards for energy efficiency.

Maintenance

Steel is susceptible to rust and corrosion. Whilst painted steel will resist corrosion, regular inspection is required to check for any rust. Cleaning and re-painting the surface where necessary will protect the metal.

Colour choice

Steel windows are available in a wide range of RAL colours.

Sustainability

Steel can be endlessly recycled without loss of quality. Its strength gives it longevity when properly maintained, and many steel windows are made from recycled content.

However, its production is energy-intensive when compared to aluminium

Cost

Steel windows are a more specialised option and typically come at a much higher cost – around four to five times more than aluminium windows.

A Sussex icon of steel

The De La Warr Pavilion is the most famous building in Bexhill. According to Discover Bexhill, it was the first welded steel frame building in this country and one of the best early examples of the International Modernist style.

Aluminium vs steel at a glance

Here’s a quick summary of the different characteristics of aluminium and steel windows:

Strength and aesthetics

Aluminium Steel
  • High strength-to-weight ratio, meaning it is light whilst providing high levels of strength for many applications
  • Versatile and adaptable to aesthetic styles
  • Superior raw strength, much heavier than aluminium
  • Greater strength offers the option for ultra-slim profiles

Security

Aluminium Steel
  • Meets all standards
  • Meets all standards

Thermal efficiency

Aluminium Steel
  • Thermal breaks included as standard, along with high-performance double or triple glazed sealed units to enhance energy efficiency
  • Typically, B and C energy ratings

Maintenance

Aluminium Steel
  • Low maintenance, does not rust or corrode
  • Can rust and corrode if not properly maintained

 

Colour choice

Aluminium Steel
  • Full RAL colour choice plus anodized colour options
  • Full RAL choice

 

Sustainability

Aluminium Steel
  • Fully recyclable
  • Fully recyclable
  • More energy-intensive processes

Cost

Aluminium Steel
  • Cost-effective alternative to steel
  • 4 to 5 times the cost of aluminium

Residential and commercial projects

Residential

For residential projects, aluminium is usually the preferable option. It delivers exceptional performance, stunning visual appeal and excellent value.

Even for homeowners who are replacing Crittall steel in their property, local authorities are often supportive of replacement with a matching design in aluminium.

Commercial

For commercial properties or architecturally sensitive buildings, both materials can be appropriate.

Aluminium is often chosen for modern office spaces, while steel may be preferable for historic buildings or design-led commercial projects.

For this Sussex school, expansive aluminium windows and doors were used throughout to achieve the sleek modern design.

Expert advice in aluminium and steel windows

At Window Wise, we specialise in high-quality aluminium window systems for homes and businesses but also collaborate with trusted partners to deliver specialist steel windows when the project requires it.

Our role is to give you unbiased, practical advice – ensuring you get the right solution, both aesthetically and for your needs and budget.

Find out more or book a design consultation

Explore our full range of stylish, secure and energy efficient aluminium windows, or see them for yourself at our Haywards Heath showroom.

Call our team on 01444 457 145 to book a design consultation at our showroom or your location.