How long do landscapes last?

In the news today is a report of Martha Schwartz lambasting Manchester City Council for destroying Exchange Square, the place her team designed in the mid 1990s. When it was built, it was much-photographed and awarded but over the years, interventions by MCC have diluted and then destroyed the space. Part of the issue here might be that these interventions should have been considered in the design stage through a more extensive consultation and assessment process, but it brought to mind a question I’ve had for some time: how long do landscapes last for?

In How Buildings Learn, Stewart Brand looks at how fashions and short-term planning combine to restrict the design life of a building much more than designers often realise: if this is true of buildings, why not landscapes too? I’d love to see a study carried out of what happens to our landscapes after they’re built and planted- how long do the planting combinations remain sustainable for, how long do the benches last, how long before the paving needs to be replaced? You know as soon as they’re built that some landscapes will need regenerating / restoring / replacing in 10 years time- either the hard landscape is shoddy, the furniture will date or the planting isn’t being maintained properly- but I suspect that there would be a number of surprising facts to come out of the study, amongst which, I suspect that the budget for a project isn’t as closely linked to longevity as many clients, suppliers and designers like to think.


Bioswales and new walkways being installed as part of Sheffield’s Grey to Green project in autumn 2015

The new Grey to Green route in Sheffield will be a great place to keep an eye on: it’s an expensive, flagship project that will change the way people navigate the city, the hard landscape looks ace and the planting will no doubt be outstanding, and it’ll be interesting to see how it develops. We took students there when the drainage was being installed and the check dams built, although I don’t understand why there’s such a complicated construction detail on them, and nor did the builders (perhaps this disconnect between the designer’s vision and the builders’ understanding is one of the first steps to a landscape breaking down). It looks great at the moment- I wonder how long for?


The completed route and planted bioswale. Photograph by Nigel Dunnett