Paving gardens to driveways – the hidden urban flood risk?

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A tidal wave of grey is sweeping away Britain’s front gardens, according to the Royal Horticultural Society (RHS), with three times as many front gardens completely paved over compared to a decade ago. Paving gardens to driveways – the hidden urban flood risk?

Understandably there are numerous reasons for this trend:

  1. With more than 38 million vehicles licensed on UK roads and a decline in freely available kerbside parking it’s no wonder homeowners are taking to paving their front garden. According to a report by the RAC a car spends around 80% of its life parked at home. In areas where the council has introduced fee paying Controlled Parking Zones for residents or where parking is at a premium it’s no surprise the only option is to pave over the front garden to create off street parking.
  2. Privately rented accommodation is most likely to have seen its front plot paved, with one in five plots “hard landscaped” from 2001-2007 according to the English Housing Survey.
  3. Busy lives and the lack of gardening knowledge has led to easy to maintain gardens which require little upkeep. Hard landscaping is seen as the only option.
  4. The boom in the ‘buy-to-let’ market has seen landlords in inner city boroughs turning to concrete in order to avoid paying for garden upkeep.
  5. TV makeover programmes have been partly blamed for the decline in gardens by encouraging people to replace greenery with patios.
  6. In addition, a parking space with a property would typically add around 8% to the value of a property according to a report published by Nationwide. Paving over the front garden is positively encouraged by the likes of Phil Spencer the presenter of Location, Location, Location and ranks No.6 in his Top 20 ways to add value to your home.

“if you want to add value in an area where parking is at a premium, then it is concrete every time. You may need planning permission, and may have to spend £10-£20,000, but added value could be £50,000 in an expensive urban location.”

Paving gardens to driveways – the hidden urban flood risk?

However, there’s an environmental cost. Paving increases the risk of flash flooding – instead of grass and soil soaking up the rain, it runs straight off paving and overwhelms drainage systems and floods roads.

Reversing the trend that has seen 4.5 million front gardens totally paved over is “vital for the nation’s health”, the RHS said, “for wildlife, to mitigate against pollution and heat waves and to protect the UK’s homes from flooding”.

The charity has called on householders to turn away from gravel, paving and concrete, now used in almost a quarter of British front gardens, and instead use plants, shrubbery and grass for the public good.  Householders are encouraged to make a pledge to help the charity transform 6,000 grey spaced into living green places by the end of 2017.

Alistair Griffiths, director of science at the RHS, said the charity “had an idea of the increase in paving front gardens, but not as much as this. We need to tackle this issue and while plants won’t solve the while thing, they are certainly part of the answer”.

The research reveals that paving over front gardens can have a “surprising” impact on the wider environment. Gardens can soak up rain, but paving, tarmac and concrete are less porous, leading to water flowing into street drains, which can cause flooding.

RHS director-general Sue Biggs, said: “We need to urgently increase plants in urban environments, and better understand how to select and use ornamental plants, not reduce them.”

Perhaps unsurprisingly, Londoners were the worst culprits for paving over their front gardens, with half paved over, up 36% in a decade. The only region to reduce the number of paved gardens was the North-east, which boosted planted front gardens by 50%.

The RHS provide an array of advice notes to home owners on how to achieve a balance of hardscaping and planting for front gardens

Paving your front garden – the Planning rules:

  In England

You will not need planning permission if a new or replacement driveway of any size uses permeable (or porous) surfacing which allows water to drain through, such as gravel, permeable concrete block paving or porous asphalt, or if the rainwater is directed to a lawn or border to drain naturally.

If the surface to be covered is more than five square metres planning permission will be needed for laying traditional, impermeable driveways that do not provide for the water to run to a permeable area. This means a planning application to be made to your local council, and there is usually a fee payable (typically around £150)

In some areas of the country, known generally as ‘designated areas’, permitted development rights are more restricted. If you live in a Conservation Area, a World Heritage Site, a National Park, an Area of Outstanding Natural Beauty or the Norfolk or Suffolk Broads, you will need to apply for planning permission for certain types of work which do not need an application in other areas

For more information, visit the government’s Planning Portal.

   In Wales

If you are intending to lay or replace a hard surface to the front of your house you must use permeable or porous materials; alternatively surface water run-off from an impermeable hard surface, such as concrete, must be directed to a permeable or porous surface to the front of your home.

You can replace or repair a small area of up to 5 square metres of existing hard-surfacing without using permeable or porous materials. For example, to repair pot holes in a driveway, or replace paving slabs in an existing patio.

Significant works of embanking or terracing to support a hard surface might need a planning application. If you live in a listed building, you may need listed building consent for any significant works whether internal or external.

For more information, visit the government’s Planning Portal and select the Welsh site option in the top right.


Additional drainage legislation:

While the law mentioned above should be sufficient for most domestic driveways, contractors and those undertaking extensive or public projects should be aware that there is the Flood and Water Management Act 2010. This sets out the requirements of Sustainable Urban Drainage (SUDS): DEFRA: information on Flood and Water Management Act 2010. Unda can assist in any Drainage Strategy and Design for Planning purposes.  Find out more about Flood Risk Assessment for Planning.


Paving gardens to driveways - the hidden urban flood risk?