Glass, polycarbonate, or PE film, all three materials have their advantages. In this article, we go through a direct test based on 8 criteria, and then recommend which one is best for different users.
Comparison criteria
We evaluate the material for the greenhouse based on 8 key criteria:
- Light transmittance (PAR, photosynthetically active radiation)
- Thermal insulation (U-value)
- Mechanical strength (hail, snow, wind)
- UV resistance (yellowing, brittleness)
- Price
- Lifespan
- Maintenance
- Aesthetics
Glass, classic with a long history
Advantages:
- Highest light transmittance (90-92%)
- Longevity: 50+ years with proper maintenance
- Premium aesthetics
- Can be completely cleaned
Disadvantages:
- Heavy (45-50 kg/m² for double), requires stronger frame
- Brittle (hail, stones)
- Poor insulation at single glazing (U = 5.8 W/m²K)
- Expensive (60-100 €/m² with assembly)
- Difficult to replace broken glass
Most suitable for: professional gardens, greenhouses, decorative greenhouses near houses.
Polycarbonate, modern choice
Advantages:
- High light transmittance (80-86%) with diffusion (less leaf burning)
- Excellent insulation (4 mm double-glazed: U = 3.3 W/m²K, 6 mm: U = 2.8)
- Practically unbreakable (does not break with hail or stones)
- Lightweight (1.3 kg/m²), possible lighter frame
- UV protective coating (against yellowing)
- Longevity 15-25 years
Disadvantages:
- Average price (25-40 €/m² for sheet + frame)
- Yellowing over time (but very slow)
- Dust accumulates in internal channels
- Thermal expansion, we must provide a gap
Most suitable for: hobby gardeners, family greenhouses, where we want long-term use without major concerns.
PE film, cheapest option
Advantages:
- Cheapest (5-10 €/m²)
- Lightweight, quick assembly
- High light transmittance (88-91%)
- Easy to replace in case of damage
Disadvantages:
- Short lifespan (2-4 years)
- Poor insulation (U = 6-7 W/m²K)
- Stretches and falls off the frame
- UV degradation (becomes brittle)
- Not suitable for winter
- Wind damages it quickly
Most suitable for: seasonal greenhouses, professional gardens with large areas, temporary solutions.
Recommendation by user profile
Our recommendations:
Hobby gardener (1-2 times a year culture change):
- → Polycarbonate 4 mm, best price/quality ratio
- Longevity 15-20 years, without worries
Full self-sufficiency (year-round use):
- → Polycarbonate 6 mm, better insulation
- Possibility of winter harvest without heating
Premium decorative greenhouse:
- → Glass, aesthetics and longevity
- With good maintenance 50+ years
Professional garden (1000+ m²):
- → Double PE film with vertical ventilation
- Replacement every 3-4 years, but the price of everything
"The material is not the most important decision when it comes to the greenhouse, but it is a decision that cannot be changed later.", Termoplast advisor
Before purchasing, be sure to check the UV protection of the polycarbonate sheet, quality ones have a 10-year warranty against yellowing (HRD-X UV protection). Cheaper sheets yellow already after 3-5 years.
Termoplast polycarbonate 4-6 mm
We supply all our greenhouses with premium polycarbonate with a 10-year UV warranty. Warranty package 10 years.
Termoplast greenhouses