Why plant or protect green walls? What’s the point of them?

There have been good studies on this, focused on green walls for buildings. These have put pound (or dollar) signs on costs of establishment and maintenance, and benefits including:

• increased property value (akin to planting street trees)
• insulating buildings to reduce air conditioning costs in hot climates
• acoustic benefit where the covering is thick
• improving biodiversity
• improving air quality by trapping dust particles
• reducing the frequency of building facade maintenance
• air temperature reduction (urban ‘heat island’)

This study concluded that ‘direct green facades’ – ie climbing plants established onto a building surface – are the most sustainable green wall type, and have a very positive net present value.

There are lots of places in Brighton where this applies – around New England for example, Westergate, American Express, and so on.

For Madeira Drive, our most famous green wall, things are a little different. However, the benefits include:

• green space for relaxation in a community where the vast majority have no garden, balcony or other outside space
• a habitat for wildlife – 100 species of plants, birds, butterflies
• a national arboretum for Japanese spindle, and place to learn how to prune, coppice and manage it
• a place to study Victorian environmental engineering
• a green lung in an otherwise sparsely vegetated area – trapping dust
• a more attractive covering for a rendered cliff face that is so much better visually than sprayed concrete
• a protective coating for the cliff face – limiting damage and deterioration from wind, rain and cold.
• a place for volunteers to get active and health
• a backdrop for TV, film, photo shoots and show piece for Brighton & Hove.

It would be useful to do some economics on this – anyone out there with the requisite skills?