Timber vs. Aluminium: Which Window Material Delivers the Best Value for Your Home?
A Homeowner's Evidence-Based Guide to Choosing the Right Windows
Quick Answer: Timber windows offer unmatched warmth, character, and thermal performance but require regular upkeep. Aluminium windows are low-maintenance, durable, and sleek, ideal for modern homes. The best choice depends on your budget, climate, home style, and willingness to maintain.
When it comes to replacing or installing new windows, the choice between timber and aluminium is one of the most consequential decisions you'll make. It affects your home's energy bills, kerb appeal, long-term maintenance costs, and even its resale value.
This guide cuts through the noise — comparing timber and aluminium windows across every key dimension so you can make a clear, confident decision. Whether you're renovating a heritage cottage or fitting out a new-build contemporary home, the answer lies in understanding what each material genuinely delivers.
Thermal Performance: Which Keeps the Heat In?
Timber Windows
Wood is a naturally poor conductor of heat, making timber frames inherently excellent insulators. In cold climates, timber windows help reduce heating costs and maintain comfortable indoor temperatures without needing engineering modifications.
Naturally low thermal conductivity (~0.12 W/mK)
Works well even without thermal breaks
Pairs exceptionally with double or triple glazing
Helps meet Passivhaus and high-performance building standards
Aluminium Windows
Aluminium is a highly conductive metal — without a thermal break (a non-conductive barrier inside the frame), it can cause heat loss and condensation. Modern aluminium windows, however, almost always include thermal break technology, which significantly closes the performance gap.
Aluminium conducts heat ~1,000x faster than timber
Thermal break frames dramatically reduce heat transfer
High-spec aluminium windows can achieve U-values of 1.0 W/m²K or lower
Suitable for all climates when properly specified
Verdict: Timber wins on raw thermal performance, but modern thermal-break aluminium is a strong competitor. For maximum energy efficiency without compromise, timber remains the top choice.
Durability and Lifespan: Which Lasts Longer?
Timber Windows
Properly maintained timber windows can last 80 years or more — there are Victorian-era homes with original timber frames still performing today. The caveat is that word: "maintained." Without regular treatment, timber is vulnerable to moisture, rot, and pest damage.
Lifespan: 40–80+ years with proper care
Vulnerable to moisture, rot, UV degradation, and insect damage
Requires repainting or re-staining every 3–7 years depending on climate
Engineered timber (e.g., laminated timber) offers improved stability
Aluminium Windows
Aluminium is inherently resistant to rust, rot, and the expansion/contraction caused by humidity and temperature swings. It holds its shape reliably over decades, making it especially well-suited to coastal, high-humidity, or high-rainfall environments.
Lifespan: 30–50+ years with minimal maintenance
Resistant to corrosion, rot, pests, and UV degradation
Powder-coat finishes last 15–25 years before touching up
Excellent performance in coastal and extreme weather environments
Verdict: Aluminium wins for hands-off durability. Timber can outlast aluminium — but only with consistent, active maintenance. In harsh or coastal climates, aluminium is the more reliable long-term bet.
Aesthetic Appeal: Which Looks Better?
Timber Windows
For many homeowners, there is simply no substitute for the warmth and character of timber. The natural grain, depth of colour, and craftsmanship of wooden frames complement traditional, period, and rural architecture in a way no synthetic material fully replicates.
Authentic look that suits heritage, Georgian, Victorian, and cottage-style homes
Paintable and stainable — customisable to any colour or finish
Warm, tactile quality that enhances interior comfort
Adds perceived prestige and value in period property markets
Aluminium Windows
Aluminium's strength allows for slimmer profiles, larger panes of glass, and cleaner sight lines — qualities that define contemporary architecture. The modern aesthetic of aluminium suits urban, industrial, and minimalist design languages exceptionally well.
Slim profiles maximise glass area and natural light
Available in thousands of RAL and powder-coat colours
Clean, precise lines suit modern and contemporary builds
Consistent finish that doesn't fade, chip, or peel for years
Verdict: It depends entirely on your home's character. Timber wins for warmth and period authenticity. Aluminium wins for clean, modern minimalism and design flexibility.
Cost and Value: What's the True Investment?
Many homeowners focus only on upfront supply-and-install costs. However, the real financial picture includes maintenance costs, energy savings, and impact on resale value over the life of the window.
Note: Costs vary significantly by region, window size, glazing specification, and installer. These figures reflect typical mid-to-high range residential projects.
Verdict: Aluminium often wins on total lifetime cost when maintenance is factored in. Timber can deliver superior ROI in heritage property markets, but requires a real maintenance budget commitment.
Sustainability and Environmental Impact
Timber Windows
Sustainably sourced timber is one of the most environmentally responsible building materials available. It is renewable, sequesters carbon during its growing phase, and biodegrades at end of life. Look for FSC (Forest Stewardship Council) or PEFC certification.
Carbon-sequestering during tree growth phase
Low embodied energy in manufacturing vs. metals
Fully biodegradable and compostable at end of life
FSC/PEFC certification confirms responsible forestry
Aluminium Windows
Aluminium production is energy-intensive, but aluminium is infinitely recyclable without quality loss. Recycled aluminium requires only 5% of the energy needed to produce virgin aluminium — making sourcing and end-of-life choices critical environmental factors.
High embodied energy in primary production
Infinitely recyclable — up to 75% of all aluminium ever produced is still in use
Extremely long product lifespan reduces replacement frequency
Choose suppliers using recycled content or green-certified aluminium
Verdict: Sustainably certified timber has the lower environmental footprint from the outset. Aluminium is more sustainable at end-of-life. Both can be responsible choices when specified thoughtfully.
Maintenance Reality: What Does Each Material Demand?
Timber Maintenance Requirements
Inspect annually for cracks, peeling paint, rot, or gaps in sealant
Repaint or re-stain exterior faces every 3–7 years
Apply flexible sealant around frames and glazing annually
Check and lubricate hardware (hinges, locks) annually
Treat any bare wood immediately to prevent moisture ingress
Aluminium Maintenance Requirements
Wipe frames down with mild soap and water 1–2x per year
Clean and lubricate hinges, handles, and locking mechanisms annually
Inspect rubber seals/gaskets every 5 years and replace as needed
Touch up any scratches in the powder coat to prevent oxidation
Verdict: Aluminium wins decisively on low maintenance. If you want windows you can essentially forget about, aluminium is the clear choice.
Conclusion: Timber vs. Aluminium - The Final Verdict
There is no single winner in the timber vs. aluminium window debate — because the best window material is the one that is right for your home, your lifestyle, and your priorities.
Choose timber if you value warmth, character, heritage authenticity, and peak thermal performance and you're committed to regular maintenance.
Choose aluminium if you prioritise low maintenance, modern aesthetics, weather resistance, and long-term reliability with minimal ongoing cost.
Consider timber-look aluminium if you want the visual warmth of wood with the durability of metal.
In either case, the quality of installation and the specification of glazing (double vs. triple) will have as much impact on performance as the frame material itself. Invest in a reputable, certified installer and you'll be happy with your windows for decades.
