For many UK homeowners, the question isn’t whether to extend — it’s how.

Do you commit to a full brick-built extension with months of construction, or is a modern aluminium glass room extension a smarter alternative?

At Casa Pergola, we’ve seen a growing number of clients comparing traditional builds with architectural glass structures. The right choice depends on budget, timeline, disruption tolerance, and the type of space you want to create.

Let’s break it down properly.

1. Build Time & Disruption

Traditional Extension

• 4–9 months typical build time

• Foundations, brickwork, roofing, electrics, plastering

• Significant disruption to your home

• Often involves moving out temporarily

Glass Room Extension

• Approx. 12–13+ weeks from sign-off

• Minimal structural disturbance

• Clean aluminium framework

• Installed with precision and efficiency

If speed and minimal disruption matter, a glass room extension is often the clear winner.

2. Planning Permission & Regulations

Traditional extensions frequently require:

• Full planning approval

• Structural engineering

• Building control sign-off

• Complex party wall agreements

Glass room extensions can, in many cases, fall within permitted development (site dependent). Every property differs, but the process is typically more streamlined.

For homeowners in areas such as London and Hertfordshire, where planning restrictions can slow projects significantly, this can be a decisive factor.

3. Cost Comparison

Traditional Brick Extension

• £60,000 – £120,000+

• Additional costs for architects, engineers, delays

Luxury Aluminium Glass Room

• Typically £25,000 – £60,000 depending on size & specification

• Integrated LED lighting

• Sliding or fixed glazing systems

• Optional heaters & blinds

• Electric roof systems

The cost difference is often substantial — especially when factoring in project overruns common with traditional builds.

4. Aesthetic & Architectural Impact

Traditional extensions are permanent structural additions. They add square footage but often blend into the existing brickwork.

A glass room extension is different.

It creates:

• Seamless indoor-outdoor flow

• Maximum natural light

• Modern architectural presence

• Fully openable sliding glass systems

The structure becomes a design feature, not just additional space.

5. Year-Round Use

Modern aluminium systems are not basic conservatories.

With:

• Double-glazed sliding glass walls

• Heat-retention roof options

• Integrated infrared heaters

• LED perimeter lighting

A well-specified glass room becomes usable in spring, summer, autumn and even winter.

This is particularly valuable in unpredictable UK weather.

6. Flexibility vs Permanence

A traditional extension is fixed — walls, doors, layout locked in.

A glass room extension can be:

• Fully enclosed

• Partially open

• Fully retracted in summer

• Adaptable to entertaining, dining, or relaxation

That flexibility is something brick cannot offer.

7. Property Value Consideration

Both options can add value, but buyers increasingly favour:

• Contemporary glass architecture

• Energy-efficient aluminium systems

• Low-maintenance materials

• Modern outdoor living spaces

In higher-value areas across United Kingdom, design-led garden rooms are becoming a strong resale advantage.

When a Traditional Extension Makes Sense

Be honest:

Choose brick and mortar if:

• You need permanent internal living space

• You are adding bedrooms or structural square footage

• You want a completely insulated room integrated into the main house

When a Glass Room Extension Is the Smarter Choice

Choose a luxury aluminium glass room if:

• You want additional entertaining space

• You value light and openness

• You want faster installation

• You prefer lower disruption

• You want architectural impact without £100k+ spend

Final Thought

The decision isn’t about which is “better.”

It’s about which suits your lifestyle.

If you’re debating a rear extension this year, it’s worth exploring whether a bespoke aluminium glass room delivers the space, flexibility, and architectural presence you’re looking for — without the delays and cost escalation of traditional building works.