Why Aluminium Bi-Folds are Replacing Traditional Extensions in 2026

Across Huddersfield and the wider Yorkshire region we’ve seen an increase in the desire for slim-profile aluminium frames that offer a heritage aesthetic but with 21st-century thermal performance.

Why choose aluminium over uPVC for large glazed areas?

While we are experts in uPVC, aluminium is ideal for wide-span openings (like bi-folds).

Strength-to-weight ratio: Aluminium frames are significantly slimmer than uPVC but can support much larger panes of glass. This means more "view" and less "frame."
The "steel-look" aesthetic: Using slimline aluminium with horizontal glazing bars gives you that iconic 1930s Art Deco or industrial look without the high cost and poor insulation of original steel.
Thermal breaks: Modern aluminium doors aren't "cold." Our systems feature a polyamide thermal break, which acts as a barrier to stop heat escaping, ensuring your room stays as warm as one with a brick wall.

Quick comparison: Extension vs. bi-fold transformation

Traditional Brick Extension:

Average Cost: £40,000+
Build Time: 3–6 Months
Natural Light: Limited by windows
Planning Permission: Often required.

Aluminium Bi-Fold / Sliding Transition:

Average Cost: £5,000 - £15,000
Build Time: 1–2 Weeks (inc. structural lintel)
Natural Light: Maximum (floor-to-ceiling)
Planning Permission: Usually "permitted development".

2026 Trend: Out with white - bring in the colour

In 2026, the "standard white" door is being replaced by architectural tones. Our aluminium range comes in 12 colours, but three palettes are dominating the market:

1. Anthracite Grey: The timeless choice for a crisp, modern look.

2. Chartwell Green: For homes looking to blend the extension into the garden.

3. Black: The essential choice for the true "steel-look" industrial vibe.

Expert Tip: If you have a north-facing room, choose a lighter interior frame colour (like White or Painswick) even if the exterior is Anthracite Grey. This bounces more natural light back into your living space.

FAQs

1. Are aluminium bi-folds energy efficient?

Yes. Our aluminium systems, paired with Pilkington KS Glass, achieve exceptionally low U-values (typically 1.4 W/m²K or lower). This exceeds the 2026 UK Building Regulations, ensuring your home remains energy efficient year-round.

2. Are bi-fold doors secure?

Absolutely. At Lockwood Windows, we prioritise security. Our doors feature multi-point locking systems, high-security cylinders, and toughened safety glass as standard, making them just as secure as a traditional solid door.

3. Which is better: bi-fold or sliding doors?

It depends on your space. Bi-folds allow the wall to "disappear" completely, perfect for entertaining. Sliding doors offer even slimmer sightlines and larger glass panes, which are better for uninterrupted views when the doors are closed.

The Lockwood difference: No salesmen, just experts

We know that a new set of doors is a significant investment. Unlike national "hard-sell" companies, Richard (our owner) personally visits every home to provide a technical assessment - not a sales pitch. We manufacture our own products in our Huddersfield factory, ensuring total quality control from the first cut of aluminium to the final installation.