Home » People & Society » Social Issues & Advocacy » Green Living & Environmental Issues » A Royal Horticultural Society Test Building Covered in Ivy Stayed 7.2 Celsius Cooler than Non-Covered Buildings. The Leaves Also Kept the Walls Dry which Lowered Humidity and Protected it from Corrosion.
Ivy Plant

A Royal Horticultural Society Test Building Covered in Ivy Stayed 7.2 Celsius Cooler than Non-Covered Buildings. The Leaves Also Kept the Walls Dry which Lowered Humidity and Protected it from Corrosion.

vy plants are known for their ability to adhere strongly to walls and other surfaces. While this may be a cause for concern for several homeowners, there are positive benefits to having ivy growing on walls. Did you know that these plants can essentially make your home cooler?

A Royal Horticultural Society (RHS) test building covered in ivy remained 7.2 degrees Celsius cooler than non-covered buildings. The leaf structure also kept the walls dry, reducing humidity and protecting the walls from corrosion.

The Organic Cooler

According to a study by the RHS and the University of Reading, ivy is the most effective plant cover for cooling buildings and reducing humidity. The paper, which was recently published in the journal Building and Environment, investigates the effect of green facades and vegetative cover on building temperature and relative humidity.

As more people turn to vertical gardening through green walls, this study is ideal for gardeners. Green walls made of climbing plants are inexpensive and have a small footprint, making them ideal for those gardening in small spaces.

Concerns have been raised that green walls may increase relative humidity and cause dampness issues on the walls, but this study shows that this is not the case. During the summer, all plant species reduced the air temperature internally and externally by at least 1 Celsius compared to ‘bare’ buildings.

The evidence showed that ivy was the best plant for summer cooling. It reduced the temperature of the internal and external walls by 7.2 Celsius and 5.7 Celsius, respectively. (Source: Royal Horticultural Society

How Can Creeping Ivy Plants Benefit Your Home During Summer and Winter Time?

Ivy provided the best summer cooling for buildings and demonstrated the greatest reduction in daily variation of relative humidity during the summer. During warm winter afternoons, RH was 5.7% lower inside ivy-covered buildings than outside. This means that ivy-covered walls keep buildings less humid during the winter.

Our research is important in growing our understanding of green walls. Many people with limited space are turning towards vertical gardening as a way of greening their homes or workplaces. We are encouraged by the findings that all the plants tested provide summer cooling benefits without causing humidity issues. 

Dr. Tijana Blanuša, RHS Principal Horticultural Scientist

With less humidity, this means fewer chances of dealing with corrosion. 

The RHS has been keen to encourage new ways of gardening and the development of technically simple vertical green walls using affordable climbing plants has proved to be a welcome addition. I hope that this research will help people decide which plants they want to grow.

Dr. Faye Thomsit-Ireland, University of Reading

(Source: Royal Horticultural Society

Appreciating the Ivy Plant

Ivy provided the best summer cooling for buildings and demonstrated the most significant reduction in daily variation of relative humidity during the summer.

Over the years, ivy has earned an undeserved reputation as a garden pest. Hopefully, this will provide an opportunity for new generations of gardeners to learn that ivy is not the enemy and can be a beautiful, versatile addition to the garden.

If you want to trim ivy in your garden, the RHS recommends first making sure there are no birds nesting there.

When working on ivy, make sure there are no birds nesting because it is an offense under the Wildlife & Countryside Act 1981 to damage or destroy a wild bird’s nest while it is in use or being built. (Source: Royal Horticultural Society

Image from LawrenceParkGarden

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