uPVC vs Aluminium Windows & Doors

The Complete Guide for Cornwall Homeowners.

If you’re planning to upgrade your windows or doors, one of the biggest decisions you’ll face is choosing between uPVC and aluminium.

At St Austell Bay Plastics, we install both every week across Cornwall — from simple replacements to full home transformations — so this guide is based on real experience, not just theory.

Get a quote for Aluminium windows and doors from one our experts here:

https://www.staustellbayplastics.co.uk/contact-us

Let’s break it down properly.

Material basics - Whats the difference?

uPVC - A rigid plastic that’s been used in UK homes for decades.

It’s designed to be:

• Affordable

• Energy efficient

• Low maintenance

You’ll typically see it in:

- Standard casement windows

- Smaller openings

- Traditional-style homes.

Aluminium - A high-strength metal used in modern glazing systems.

It’s known for:

• Exceptional strength

• Slim, architectural frames

• Premium finish

Commonly used for:

- Bi-fold doors.

- Sliding doors.

- Large feature windows.

- Modern extensions.

Cost: Short term vs longterm

uPVC:

• Lower upfront cost

• Ideal for tight budgets

• Great for rental properties or quick upgrades

Aluminium:

• Higher initial investment

• But significantly longer lifespan

• Adds more perceived value to your property

💡 Real-world insight:

Many Cornwall homeowners now see aluminium as an investment, not just a purchase — especially when improving resale value or kerb appeal.

🌊 Cornwall Climate performance.

Living in Cornwall means your windows need to handle: Salt air, High winds and Driving rain.

uPVC

✔ Won’t rot or corrode

✔ Performs well in most conditions

Aluminium

✔ Powder-coated for excellent corrosion resistance

✔ Handles extreme exposure better long-term

✔ Less expansion/contraction in temperature swings

Key takeaway:

Both perform well — but aluminium is often the better choice for coastal and exposed locations.

Still Thinking about your options?

Whether you’re still comparing or ready for a quote, we’re happy to help.

We can:

✔ Talk you through both options

✔ Show real examples

✔ Recommend what suits your property best Visit: https://www.staustellbayplastics.co.uk/

We install aluminium windows and doors across Cornwall including St Austell,

Truro, Newquay, Falmouth and beyond.