What Is Better for Greenhouses: Plastic or Glass Glazing?

Light is the heartbeat of plant growth. This means that, in a greenhouse, choosing the right glazing impacts the success of your growing.  There are two options: plastic’s flexibility and the timeless durability of glass.

In this guide, we’ll discuss each material. Join us as we go through the ins and outs to help you make an informed decision tailored to your needs. Read and discover which glazing shines brightest for your flourishing greens!

Greenhouse Glazing Explained

Glazing is the protective covering that completes a garden greenhouse. It plays a pivotal role in establishing a controlled environment for plant growth. Imagine it as the structure’s skin, doing important jobs for cultivation success.

First, insulation: glazing traps heat, fostering a climate conducive to optimal plant development. Second, light transmission: it enables sunlight to penetrate while diffusing it evenly. This ensures plants receive the essential rays for photosynthesis. Last, durability: glazing shields plants from external elements. It safeguards them from harsh weather conditions.

Greenhouse glazing does more than just protect. It manages temperature, light, and shelter for a thriving greenhouse ecosystem. Understanding these is crucial when choosing materials like plastic or glass.

Plastic Glazing

BillyOh 4000 Lincoln Wooden Polycarbonate Greenhouse
BillyOh 4000 Lincoln Wooden Polycarbonate Greenhouse

Plastic glazing is a protective covering for greenhouses made from plastic materials like:

  • Polyethylene: Valued for its affordability and flexibility. It allows ample light transmission, fostering plant growth. Yet, it may have a shorter lifespan and can degrade over time, particularly with UV exposure. Regular inspection and maintenance are essential to ensure longevity.
  • Polycarbonate: Renowned for its impact resistance and excellent light diffusion. It offers better insulation than glass and is often UV-resistant. Though pricier, its longevity and insulating properties make it worth investing in. Overall, polycarbonate greenhouses ensure a stable environment for plant cultivation. Regular cleaning maintains its clarity and efficiency.


Serving as a transparent barrier, it allows sunlight to enter the greenhouse. At the same time, it creates a controlled environment for plant growth. The plastic material is chosen for its flexibility, lightweightness, and cost-effectiveness. Moreover, it helps regulate temperature and humidity, providing an optimal setting for cultivating plants. But there’s more!



BillyOh 4000 Lincoln Wooden Polycarbonate Greenhouse
BillyOh 4000 Lincoln Wooden Polycarbonate Greenhouse

Plastic glazing offers a myriad of advantages beyond its well-known traits. To add, plastic is an excellent insulator, helping maintain a stable greenhouse temperature. It also provides diffused light, reducing shadows and promoting even plant growth. This is particularly beneficial for light-sensitive crops.

The versatility of plastic accommodates various greenhouse designs and sizes. This makes it adaptable to different horticultural needs. Additionally, plastic glazing materials often resist breakage and are UV-stabilised, ensuring prolonged durability.


With these qualities, plastic stands out as a practical choice. Ideal for those seeking efficient, cost-conscious, and sturdy greenhouse solutions.


Behind the numerous advantages, longevity concerns and potential aesthetic impacts are worth considering. Over time, plastic may degrade due to UV exposure, affecting its lifespan. To mitigate this, regular inspection and timely replacement of worn-out panels are crucial.

Aesthetic concerns arise from the wear and tear that plastic can exhibit. This, in turn, impacts the overall visual appeal of the greenhouse. To counter this, periodic cleaning and maintenance routines help uphold the greenhouse’s appearance.

Despite these considerations, the overall benefits of plastic glazing often outweigh these challenges. The key here is to choose high-quality, UV-resistant materials and proper maintenance practices. Such practices can enhance the longevity and visual appeal of plastic-glazed greenhouses.

Glass Glazing

Interior view of a Victorian glass greenhouse with a display of potted plants on shelves.

(Image Credit: Flickr)


Glass glazing refers to the use of glass as a transparent covering for greenhouses. Like the plastic type, it serves as a protective barrier. The glass also allows sunlight to penetrate while creating a controlled plant environment.


This glazing material is known for its durability and clarity. Various types of glass can be utilised in greenhouse construction, including:

  • Float glass: Produced by floating molten glass on a bed of molten metal. This results in a smooth and uniform surface. It provides excellent light transmission and clarity. However, it is more susceptible to breakage, and thus the need for regular maintenance.
  • Tempered glass: Undergoes a process of controlled heating and rapid cooling. This type of glass is highly resistant to breakage and shattering. Its durability and safety features contribute to a longer lifespan. Moreover, this reduces maintenance needs compared to other glass types.


Glass is valued for its ability to let in lots of light efficiently and create a stable climate. A classic choice for a more enduring and traditional solution for greenhouse cultivation.




Glass offers the advantage of being resistant to scratches and discolouration over time. Its smooth surface is easy to clean, ensuring long-lasting transparency. Moreover, glass provides a timeless aesthetic. Its transparency enhances the visual aspect of the greenhouse.

Glass excels in transmitting sunlight efficiently, providing plants with ample energy for photosynthesis. Simultaneously, its thermal properties help regulate temperatures inside the greenhouse. Glass traps also heat effectively. This creates a stable and warm environment conducive to plant growth.


Despite its merits, glass has drawbacks. Its weight can pose challenges in construction and may require sturdier framing. Glass may need extra insulation to prevent heat loss, especially in colder climates. The initial cost of glass is often higher than other materials, which adds up to the overall expenses.


Furthermore, safety is a concern with glass in greenhouses. Breakage can occur due to impacts or extreme weather conditions. This, in turn, poses risks to both plants and people. To mitigate this, using tempered glass is recommended. Proper maintenance is essential to ensure a safe greenhouse environment.


Making the Decision

Consider factors like cost, insulation needs, and climate when deciding plastic vs glass. Both materials have pros and cons that affect how well your plants grow.

Different plants and climates also have unique requirements. Evaluate sunlight needs, insulation demands, and temperature considerations. Such considerations will help align your choice with your specific greenhouse goals.

To make an informed decision, assess your budget, local climate, and the types of plants you wish to grow. For reference, check out these best plants for greenhouse. Additionally, prioritise other factors like durability, maintenance, and aesthetic preferences. Tailor your choice to match the specific needs and circumstances of your greenhouse.


The choice between plastic and glass glazing hinges on your unique needs. While plastic offers affordability and flexibility, glass boasts durability and timeless appeal. Think about the climate, the type of plants, and your budget, as each material has its good points. Your choice comes down to finding a balance between what works and what looks good.

Discover our range of greenhouses for sale, featuring a wooden polycarbonate greenhouse unit. Explore today at Garden Buildings Direct! Up next on your reading list: The Best Polycarbonate Greenhouses UK