An attached greenhouse — also known as a lean-to greenhouse — is a greenhouse structure that is built directly against an existing building, such as a house, garage, or shed. This design offers a range of benefits for gardeners who want to maximize growing space, reduce construction costs, and improve energy efficiency.

What is an Attached Greenhouse?

Unlike standalone greenhouses that require their own walls and foundations, attached greenhouses share one wall with the main building. This often means one side of the greenhouse is made of the existing building’s wall, while the other three sides are glass, polycarbonate, or plastic to allow sunlight in.

Attached greenhouses can be designed in various sizes — from small structures suitable for patios to large rooms used for year-round growing.

Benefits of an Attached Greenhouse

1. Energy Efficiency and Cost Savings

Because an attached greenhouse uses the existing building’s wall, it gains warmth from the indoor environment. The wall acts as an additional thermal mass, retaining heat and moderating temperatures inside the greenhouse. This reduces the need for extra heating during colder months, lowering energy bills.

Additionally, construction costs are generally lower since one wall already exists, and fewer materials are needed.

2. Space-Saving Design

For gardeners with limited outdoor space, an attached greenhouse is an ideal solution. It fits snugly alongside your home or other structure, utilizing otherwise unused space such as patios, decks, or narrow yard sides.

3. Convenient Access

Since the greenhouse is attached to your home, it offers easy access to your plants, especially during adverse weather. This convenience encourages more frequent care and harvesting, improving your gardening experience.

4. Versatility

Attached greenhouses can serve multiple purposes:

• Starting seedlings early in the season

• Growing tropical plants that require warmth and humidity

• Extending the growing season for vegetables and herbs

• Creating a relaxing sunroom or garden retreat

5. Protection from Harsh Weather

Sharing a wall with a building offers better protection from wind, rain, and extreme temperatures. This creates a more stable microclimate for your plants, which is especially useful in regions with unpredictable weather.

Design Considerations

When planning an attached greenhouse, consider the following:

• Orientation: The greenhouse should ideally face south (in the Northern Hemisphere) or north (in the Southern Hemisphere) to maximize sunlight exposure.

• Building Wall Condition: Ensure the existing wall is structurally sound and well insulated to support the greenhouse’s function.

• Ventilation: Proper ventilation is essential to regulate humidity and temperature, preventing mold and overheating.

• Materials: Use durable glazing materials such as tempered glass or polycarbonate for safety and insulation.

• Foundation: Although one wall is shared, the greenhouse still requires a solid foundation to maintain stability and drainage.

Conclusion

An attached greenhouse offers gardeners an efficient, cost-effective way to grow plants year-round while saving space and energy. By leveraging the existing structure of a home or building, it provides warmth, protection, and convenience. Whether you want to start seedlings early, grow exotic plants, or simply enjoy a green retreat, an attached greenhouse is a smart choice for both novice and experienced gardeners.