Aluminium vs uPVC windows: An honest comparison

In short

Lower price	uPVC
Slimmer frames, more glass	Aluminium
Energy performance	Both can reach 1.4 W/m²K or better
Dark and custom colours	Aluminium
Big openings and doors	Aluminium
Longest service life	Aluminium

We supply and fit both aluminium and uPVC windows, so we have no reason to push you one way. The truth is that both materials make good windows, and the right choice depends on your house, your budget and what you care about most.

Price

uPVC windows are cheaper, often noticeably so. On a tight budget, a good uPVC window beats a poor aluminium one every time. Aluminium costs more up front because the material and the engineering cost more.

Frame size and glass area

Aluminium is much stiffer than uPVC, so the frames and sashes can be slimmer for the same size of window. On a large window, that means more glass, more daylight and a cleaner look. uPVC needs thicker sections, often with steel reinforcement inside, to stay rigid.

Energy performance

Both can be very energy-efficient. Modern aluminium windows use a thermal break, and both materials can reach a whole-window U-value of 1.4 W/m²K or better, the level the SEAI windows grant requires. The glass and the quality of the installation matter as much as the frame material. Always compare whole-window U-values.

Colour and finish

Aluminium is powder coated in any RAL colour, and dark colours hold up well in sun. uPVC comes in white as standard. Colours are usually foils or coatings, and dark uPVC frames absorb more heat. If you want anthracite grey, black or a bold colour, aluminium is the more natural fit.

Strength and big openings

For large sliding doors, bifolds and big picture windows, aluminium’s strength lets panels and panes be larger. That’s why most large glazed doors are aluminium.

Lifespan and maintenance

Both need little maintenance: wash them, clear the drainage slots and oil the hinges. Aluminium frames tend to have a longer service life and keep their looks longer, especially in dark colours. Near the sea, aluminium needs a marine-grade finish and regular washing. uPVC isn’t affected by salt.

Sustainability

Aluminium can be recycled repeatedly without losing quality, and recycled aluminium needs a fraction of the energy of new metal. uPVC can also be recycled, and recycling schemes are improving. A long service life is good for the environment with either material.

So which should you choose?

• Choose aluminium for slim frames, dark or custom colours, big openings, a modern look and the longest life.
• Choose uPVC if budget is the deciding factor and white or standard colours suit the house.

See our aluminium windows or all window types.

Aluminium and uPVC window FAQs

Are aluminium windows better than uPVC?

They’re better for slim frames, big openings, colours and lifespan. uPVC is better on price. Both can achieve excellent energy performance, so the right choice depends on your priorities and budget.

Are aluminium windows colder than uPVC?

Not modern ones. Thermally broken aluminium windows can reach a U-value of 1.4 W/m²K or better, the same performance level as good uPVC windows.

Do aluminium windows cost more than uPVC?

Yes, aluminium windows usually cost more up front. Over their life the gap narrows, because aluminium frames tend to last longer and keep their appearance.

Which lasts longer, aluminium or uPVC?

Aluminium frames generally have a longer service life and keep their colour and shape longer, especially in dark colours. Both need occasional cleaning and hardware maintenance.