With cars getting wider and on-street parking space at a premium, driveway installations are likely to be a key investment for UK property owners during 2024.

Jamie Gledhill, Technical Engineer at Brett Landscaping

Jamie Gledhill, Technical Engineer at Brett Landscaping, has advice for builders on the main requirements and considerations, the enduring advantages of permeable block paving and how to upsell water management systems for environment-conscious customers.

The land battle

Last year Prime Minister Rishi Sunak raised eyebrows when he declared an end to the ‘war on motorists’, focusing on traffic-calming schemes and the government’s pledge to ban the sale of new petrol and diesel cars by 2035. If there is a war on motorists, I would argue that it is actually a battle over territory.

According to research from car manufacturer Vauxhall, 40% of motorists don’t have access to a driveway, which rises to 60% of motorists who live in our towns[1]. This comes at a time when the clean transport campaign group Transport & Environment has revealed that new car models are getting too big for British roads, exceeding the 180cm minimum for on-street parking[2].

It is no wonder that research by Aviva Home Insurance in summer 2022 found that as many as 25% of homeowners have already made changes to their outside space to accommodate cars and other vehicles with a further 17% of homeowners planning to increase their available driveway areas[3].

However, this motorist demand for space needs to find a working balance with the homeowner responsibility over surface water management on their property – essentially the rainwater running off surfaces such as driveways in a way that seeks to minimise risk and impact on roadside drains, sewers and to neighbouring land/property. This is an issue builders need to flag with their customers before work starts.

The rules of engagement

Permeable block paving in situ

To begin with, it is vital to note that since 2008, any installation of a driveway using an impermeable surface material that doesn’t actively absorb rainwater and is more than five square metres in area size, will require planning permission from the customer’s local planning authority.

For a sense of scale, the standard UK car park bay size of 2.5 metres by 5 metres generates an area of 12.5 square metres, so it is a very low threshold before planning permission is a requirement when using impermeable driveway materials such as asphalt, porcelain paving slabs or tarmac.

Planning permission may also be a requirement if the property is in a special designated conservation area, and the plan is to convert a significant proportion of garden land.

These regulations were introduced to account for the huge rise in properties where garden land was being converted to additional parking spaces for cars, leading to ‘urban creep’. This has reduced the available area for rainwater to be absorbed naturally back into the ground, leading to more surface water runoff reaching roadside drains and sewer systems which were never intended to take this additional surface water.

As the intensity of rainfall events increases with the effects of climate change, many of those in the industry including legislators want to encourage a more considerate way of dealing with surface water running off private property.

Permeable block paving

The solution to a balance between usable area for traffic, effective stormwater management and meeting legal requirements is available and in use. Planning permission is rarely required if using concrete block permeable paving as long as it is installed with a fully permeable sub-base. These systems, such as Brett Landscaping’s Invicta Flow and Omega Flow, and others like them, offer great design flexibility to meet homeowner need for space, they absorb and manage rainwater to meet legal requirements, as well ensuring issues on surface water pooling do not affect the final installation.

Builders and driveway specialists do have other incentives for advising the use of permeable block paving. For a start, the material is readily available in a wide range of product system options and remains at a competitive cost per square metre comparable to permeable tarmac.

Permeable block paving can be installed in wet weather, which allows work to continue, even during the unpredictable UK downpours.

If the paving is installed properly the ongoing maintenance requirements and costs for the homeowner is minimal, ensuring costly call backs to previous work can be avoided.

Homeowners also have a financial incentive, as some water companies will offer money off water bills if the water landing on a property is disconnected from the local sewer system.

The social responsibility case

All the above sets out the current requirements and practicalities of a driveway conversion or extension. Brett Landscaping works closely with the Association of SuDS Authorities (ASA), which represents local authorities across England with supporting the delivery of sustainable drainage.

Co-Chair of the ASA, and head of the Flood Risk Management Team at Lancashire County Council, Laura Bigley, argues that at a time of increasing storm events placing existing drainage systems under growing pressure, homeowners have an intrinsic social responsibility to think about how their renovations will affect the properties in their vicinity:

“Land drainage law is a complex area of regulations, but at its centre is a very simple premise – the landowner is responsible for the drainage on their land and should not cause a nuisance to others. While homeowners should not alter their terrain without understanding how this will affect other properties, there is still a situation where work often proceeds without due diligence by the property owner and undertaken by builders.”

“We hope that in time permeable surfaces will become ‘the norm’ for homeowners to use on their driveways and garden areas. This will help us to all contribute towards responsibly managing surface water from our property by keeping it out of the drainage systems and allowing it to mimic natural processes.”

Flood and Drought resilent driveways

The ASA advises that there are some measures that can be taken to compensate for the lost permeable area and habitat an extended driveway may cause. This provides an opportunity for builders to offer further advice on how to create a flood and drought resilient garden.

The planting of evergreen hedges along the boundaries of a driveway in preference to fencing assists with surface water management and absorption, but also provides noise reduction and improvement in air quality as well as habitat for birds, hedgehogs and other wildlife.

The installation of water butts is another great option for homeowners to consider. Not only are they cheap and easy to install, but they can remove many litres of rainwater from the drains and sewers, helping to better manage flood risk in the community. There are many sizes, styles and even ‘smart’ water butts to choose from to suit any sized space and aesthetic.

With on-street parking space at a premium and family cars getting larger, driveway extensions projects are going to be on the rise.

Advising customers of permeable driveway options to avoid the need for planning permission, and that ‘urban creep’ can be offset with green solutions that removes pressure to existing drainage systems does not have to be a bruising battle, but instead can lead to inspirational design that is both practical, cost effective and socially responsible.

This is the longer version of an article that has appeared in Professional Builder.

[1] Vauxhall research: https://www.thisismoney.co.uk/money/electriccars/article-12404667/Over-two-thirds-councils-no-plans-install-residential-street-chargers-electric-cars.html

[2] Car size research: https://www.transportenvironment.org/discover/cars-are-getting-too-big-for-british-roads-new-research-shows/#:~:text=On%20average%20cars%20were%20found,two%20decades%20up%20to%202020

[3] Homeowner attitudes: https://www.aviva.com/newsroom/news-releases/2022/07/gardens-being-uprooted-in-favour-of-driveways-and-artificial-grass-new-research-reveals/

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