Wooden vs Aluminium Greenhouses: Cost, Heat & Maintenance
Wooden greenhouses cost 30–50% more than aluminium but retain heat up to 40% better. Timber is a natural insulator. Aluminium frames need no maintenance and let in more light through thinner bars. Wooden frames suit traditional gardens and exposed sites where weight matters. Most UK buyers choose aluminium for low upkeep. Serious growers wanting a garden focal point often prefer wood.
Key Takeaways
- Wooden greenhouses cost 30–50% more but stay 2–4°C warmer overnight without heating
- Aluminium needs zero maintenance; ThermoWood needs very little thanks to heat treatment at 200°C
- A Swallow Kingfisher 6x6 costs £2,958 including installation, staging, and auto vents
- Choose wood for heat retention and appearance; choose aluminium for budget and low upkeep
Installer's Note
We've fitted both types across hundreds of UK gardens over 15 years. Aluminium goes up faster and you can forget about it. Wooden ones take longer to install, but they feel different inside. Warmer, quieter, and they look like they belong. The Swallow ThermoWood frames we fit are a cut above on the timber side. If your budget stretches, timber is the one you won't regret.
How wooden and aluminium greenhouses compare
Aluminium has dominated the UK greenhouse market for decades. It's light, cheap to produce, and needs almost zero maintenance. But wooden greenhouses have never gone away, and for good reason.
The choice comes down to four things: heat retention, maintenance, cost, and appearance. Get clear on your priorities and the decision becomes straightforward.
Heat retention and insulation
Timber is a natural insulator. A wooden frame loses heat far more slowly than an aluminium one. That matters in spring when you're starting seeds, and in autumn when you're squeezing the last tomatoes off the vine.
Aluminium conducts heat roughly 1,000 times faster than wood. In practice, that means a wooden greenhouse stays 2–4°C warmer overnight without any additional heating. Over a full growing season, that temperature buffer adds weeks to both ends.
If you're in a northern or exposed area, that extra warmth makes a real difference. Wooden greenhouses are heavier too. A Swallow Kingfisher 6x8 weighs around 180kg versus 40–50kg for a typical aluminium 6x8. That weight keeps them planted during storms.
Want to keep your greenhouse warm without running up bills? Read our guide to heating a greenhouse without electricity. For electric and gas options, see how to heat a greenhouse.
Maintenance requirements
This is where aluminium wins clearly. A powder-coated aluminium frame needs nothing beyond an occasional wipe-down. It won't rot, warp, or need repainting.
Traditional softwood greenhouses need treating every 1–2 years with a microporous paint or preservative. Skip it and you'll see the wood grey, crack, and eventually rot at the joints.
ThermoWood changes the equation. Swallow greenhouses use heat-treated timber (ThermoWood®) that's been kiln-processed at over 200°C. This removes the moisture and sugars that cause rot. The result is timber that's naturally resistant to decay without chemical treatment. Swallow back this with a 12-year warranty, one of the longest in the UK for a wooden greenhouse.
You can leave ThermoWood in its natural honey-brown finish or paint it any colour you like. Either way, it holds up far longer than untreated softwood.
Storms can damage any greenhouse frame. Our greenhouse wind damage guide covers prevention steps for both types.
Cost comparison
Aluminium greenhouses start from around £200 for a basic 6x4 model. A comparable wooden greenhouse starts around £2,000. At the premium end, large Swallow models run to £6,000–£9,000.
That gap is real. But hidden costs with budget aluminium narrow it:
- Aluminium frames rarely include installation — add £200–£500 depending on size
- Staging and shelving are usually extras — another £100–£300
- Auto roof vents are optional on most aluminium models — £30–£50 each
Swallow wooden greenhouses include installation, staging, auto vents, and locking doors in the price. The Swallow Kingfisher 6x6 at £2,958 includes everything fitted in your garden.
An aluminium 6x6 plus installation, staging, and auto vents totals £700–£1,000. The real gap is closer to 2x than 4x once you add the extras.
Appearance and garden fit
A wooden greenhouse looks like it grew there. Timber blends with fencing, decking, and planting in a way aluminium never quite manages. In a cottage garden or a period property, a wooden greenhouse is the obvious choice.
Modern aluminium greenhouses have closed the gap with painted finishes in green, black, and anthracite. But the glazing bars are still thin and metallic. Wooden frames have a depth and texture that photographs don't fully capture. You notice it most when you're inside.
Swallow offer ThermoWood (natural), oiled, or painted finishes in eight colours. Options include Midnight, Olive, Summer Green, and Robins Egg Blue. You can match your greenhouse to your garden scheme exactly.
Already have a colour theme in the garden? Take a look at our painted wooden greenhouse range. For positioning advice, see our guide on the best position for a greenhouse.
Which type is right for you?
Choose aluminium if you want the lowest upfront cost, zero maintenance, and maximum light. It's the practical choice for most first-time buyers. Browse our full range of aluminium greenhouses from £200.
Choose wood if you want better heat retention and a traditional look. Timber suits exposed or windy sites and period properties. Browse our wooden greenhouses from Swallow.
Matt's Tip: Think About Where You're Putting It
Wooden greenhouses are heavy. A Swallow Kingfisher 6x8 weighs around 180kg. You need a proper level base — concrete or paving slabs, not gravel. We've seen timber frames twist on uneven ground within the first year. Get the base right and the greenhouse lasts decades. Aluminium is more forgiving on a slightly uneven surface, but still benefits from a solid base.
New to greenhouse growing? Our best beginner's greenhouse guide covers what to look for. Before ordering either type, sort your base first. Our greenhouse base preparation guide covers concrete, paving slab, and gravel options.
| Feature | Aluminium | Wood (ThermoWood) |
|---|---|---|
| Starting price (6x4) | From £200 | From £2,089 |
| Heat retention | Low — metal conducts heat fast | High — natural insulation |
| Maintenance | None (wipe clean) | Minimal with ThermoWood |
| Warranty (typical) | 10–15 years | 12 years (Swallow) |
| Weight (6x8 approx.) | 40–50kg | 160–180kg |
| Wind resistance | Good (needs anchoring) | Excellent (heavy, rigid) |
| Installation included | Rarely | Yes (Swallow) |
| Light transmission | Higher (thin bars) | Slightly lower (thicker bars) |
| Colour options | 3–5 finishes | 8+ paint colours or natural |
| Matt's Pick | Best for budget and low maintenance | Best for heat, appearance, and exposed sites ★ |
|
Matt's Pick for Aluminium GreenhousesBest For: First-time buyers wanting a solid 8x6 with no maintenance Why I Recommend It: The Apollo 5000 is our most popular aluminium greenhouse. Toughened glass, integral gutters, and a stable 8x6 footprint. The black frame looks smart in any garden. We've fitted hundreds of these and they go up clean every time. Price: £814 |
|
Matt's Pick for Wooden GreenhousesBest For: Most growers wanting a wooden greenhouse that's not too big, not too small Why I Recommend It: The Kingfisher 6x6 is the size we fit most often. Big enough for staging on one side and a growing bed on the other. ThermoWood frame, 12-year warranty, toughened glass, auto vents, and locking door all included. We install it in a day. Price: £2,958 (includes installation) |
Wooden greenhouses worth considering
All three include free installation, toughened glass, auto vents, and staging. The Swallow Lark 4x4 at £2,575 suits tight spaces. The Raven 8x8 at £3,871 has double doors and staging space on both sides.
Still deciding on glazing? Our glass vs polycarbonate guide covers that.
Frequently asked questions
Are wooden greenhouses warmer than aluminium?
Yes, wood insulates far better than aluminium. A wooden greenhouse stays 2–4°C warmer overnight without heating. Timber conducts heat roughly 1,000 times slower than aluminium. In spring and autumn, that buffer protects young plants from overnight drops.
How long does a wooden greenhouse last?
ThermoWood frames last 20+ years with minimal upkeep. Heat treatment removes the moisture and sugars that cause rot. Swallow greenhouses carry a 12-year warranty on the frame. Untreated softwood frames need preservative every 1–2 years to reach similar lifespans.
Do wooden greenhouses need a lot of maintenance?
ThermoWood greenhouses need very little maintenance. The heat-treated timber resists rot naturally without chemical preservatives. If left unpainted, it weathers to a silver-grey over time. Traditional softwood frames need treating every 1–2 years with microporous paint or preservative to prevent cracking and rot.
Is a wooden greenhouse worth the extra cost?
For serious growers, a wooden greenhouse is worth the investment. They cost 2–3x more upfront than aluminium. But they retain heat better, handle wind better, and look more natural in a garden setting. They also hold their value. A well-maintained timber greenhouse adds to a property's appeal in a way aluminium rarely does.
Can I paint a wooden greenhouse any colour?
Yes, timber takes paint easily and holds colour well. Swallow offer eight factory-applied colours including Midnight, Olive, and Robins Egg Blue. You can also buy the ThermoWood finish and paint it yourself later using any exterior microporous paint. Aluminium greenhouses are limited to the manufacturer's powder-coat options.
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- 12 helpful pointers for buying greenhouses
Need help choosing between wooden and aluminium? Email us at info@greenhousestores.co.uk and we'll recommend the best option for your garden.
