How to create a great driveway
Whether you’re building a new driveway or updating an existing one, here we lay out the essentials, from the rules and regs you need to follow to the various material options
The driveway is the first thing you set eyes on as you approach a house — but all too often, it’s one of the most overlooked areas of self-build and renovation projects. As well as playing an important role in boosting your home’s kerb appeal, the driveway serves an important practical purpose.
The rules & regs
One of the key stipulations you’ll need to adhere to when constructing or re-vamping your driveway is concerned with surface water runoff. “Over recent years of climate change we have seen increased flooding. Government legislation introduced in 2008 aims to minimise any additional load on the existing sewerage drainage systems already in place,” says Mick Haley of The Gentleman Architect. The key regulations you need to abide by are laid out in SUDS (Sustainable Drainage Systems 2008).
Essentially, in 2008 Permitted Development rights were updated to state that if any hard surface to be covered is more than 5m2 between the front of your house and the highway, then the laying of non-porous surfacing requires planning permission. But, using a porous (permeable) surfacing like permeable block pavers, which comply with SUDS guidelines, does not need planning consent. In Wales, new rules came into force in January 2019 that stipulate all developments where the construction area is greater than 100m2 require SUDS approval, too.
Whether you’re building a new driveway or replacing an existing one, the most straightforward solution is to use or replace impermeable surfaces with a porous alternative that allows rainwater to pass through. There are various permeable, Sudscompliant options including gravel, permeable concrete block pavers or porous asphalt, to name a few (see ‘Material Options’ on page 83).
If opting for a porous surface treatment, you’ll also need to incorporate a permeable subbase. The depth of this layer depends on the size and load of the vehicles that will be using it — typically, a depth of 150mm is adequate for most residential projects. The most common material is MOT Type 1, which is a mixture of crushed rock particles measuring between 40mm at the largest, mixed with smaller particles that have been ground down to a finer form, right down to dust.
This blend is ideal for driveway drainage as it is designed to ensure there are minimal voids in the material once it has been compacted. The larger, interlocking stones ensure the layer remains in place as water drains through it, as they can’t be washed away as easily.
If you hope to instead use a hard surface driveway such as non-porous tarmac, you must incorporate adequate drainage for the effective discharge of water to a pervious area of ground, such as a grass garden — this will not need planning permission but is covered in Part H of the Building Regs. A typical solution would be to incorporate a drain outlet to a soakaway. “This is essentially a large underground pit filled with gravel that allows for better drainage. However, it must be positioned well away from the foundations ideally 5m from the house itself and 2.5m from the boundary,” says Mick Haley of The Gentleman Architect.
According to Building Regs, where excess water is to be drained onto ground next to the area of hard surfacing, the edge of the paving should sit above or flush with the area of pervious ground to ensure sufficient runoff.
Typically, all ground levels should slope away from the house. However, this isn’t always possible, so where necessary you can incorporate additional drainage channels and gullies to direct water towards your soakaway. You can also build extra capacity into your soakaway(s).