5 Key Differences: Glass vs. Polycarbonate Greenhouses

When planning a glass greenhouse or polycarbonate greenhouse, one of your most important choices is the type of glazing material. Both offer unique advantages — but depending on your goals, space, and budget, one may clearly be a better fit. This guide breaks down the key differences to help you choose with confidence.

1. Appearance and Aesthetic

Glass greenhouses have a timeless, classic look. Their crystal-clear walls and roof offer unobstructed views of your plants and garden beyond. This transparency makes them a popular choice for garden enthusiasts who value form as much as function.

Polycarbonate greenhouses, on the other hand, have a slightly matte or frosted appearance. They diffuse light more than they let it shine directly through, which may not offer the same visual elegance — but can benefit certain growing conditions.

2. Light Transmission and Growing Conditions

Glass offers superior clarity and light transmission, which is ideal for sun-loving plants like tomatoes or orchids. It allows direct sunlight in, helping create ideal growing conditions in spring and fall.

Polycarbonate panels provide a softer, more diffused light. This helps prevent leaf burn in hot climates and can reduce internal temperature fluctuations. However, less light means slightly slower growth for some crops.

3. Durability and Lifespan

A well-built glass greenhouse can last for decades. At Sturdi-Built, we use tempered glass that is highly durable and less prone to breakage. While glass is heavier and requires a sturdy frame, it stands the test of time.

Polycarbonate greenhouses have a shorter lifespan — typically 10 to 15 years before panels may yellow, crack, or degrade due to UV exposure. For this reason, Sturdi-Built is phasing out polycarbonate in most new models in favor of long-lasting materials like redwood and tempered glass.

4. Insulation and Energy Efficiency

Polycarbonate panels are often better insulators than single-pane glass. Twin-wall or triple-wall polycarbonate traps air between layers, making it more energy efficient. This is beneficial for year-round growing, especially in colder climates.

However, glass greenhouses can also be energy efficient when built with insulated glazing and paired with proper ventilation and heating systems. For those looking to extend the growing season without sacrificing looks, glass remains a solid option.

5. Cost and Investment

Polycarbonate greenhouses generally cost less upfront, making them appealing to DIY gardeners or those testing greenhouse gardening for the first time. However, replacement costs over time can add up.

A glass greenhouse requires a higher initial investment, but it can increase property value, reduce long-term maintenance, and serve as a permanent architectural feature in your garden. As noted by The Spruce, investing in quality materials can pay off over time.

Which Greenhouse Type Is Right for You?

Ask yourself these questions:

• Do you want a greenhouse that enhances your garden’s appearance? → Go with glass.

• Is long-term durability a priority? → Choose glass.

• Are you in a hot climate or need high insulation? → Consider polycarbonate.

• Are you just starting out and want something more affordable? → Polycarbonate may work — for now.

For a deeper dive into how kits compare, explore our collection of glass greenhouse models or read about why we’re phasing out polycarbonate greenhouses.

Conclusion

Choosing between a glass greenhouse and polycarbonate greenhouse depends on your priorities. If beauty, durability, and long-term performance top your list, a well-built glass model is worth the investment. Polycarbonate may be suitable for temporary or budget-conscious builds, but its shorter lifespan often means higher long-term costs.

Either way, understanding the differences helps ensure your greenhouse fits your lifestyle and gardening goals.