Planning a New Driveway: What Matters Before the Surface

The surface is the last thing to arrive and the least of the decisions. What a lasting driveway is really made of, plus the rules on rainwater and on getting a car across the pavement, worth settling before anyone digs.

A driveway fails from underneath. The gravel, the blocks, the resin. That’s the part you can see. What decides whether a drive still looks right in fifteen years is the couple of hundred millimetres below: the dig-out, the stone, the compaction, and where the water goes. Get those right and almost any surface will serve you. Get them wrong and you get a drive that dips at the gate two winters in, whatever you paid per square metre.

The ground does the work

Strip back any decent drive and you’ll find a bed of crushed stone, usually a graded aggregate the trade calls Type 1, or an open-graded version where the drive needs to drain down through itself. Its job is to spread a wheel load of half a tonne until the ground beneath barely notices. The trimmed ground it sits on is what we call the formation level, and it matters just as much: soft spots get dug out and filled, not covered over and hoped for.

As a rule of thumb, a car drive wants at least 150mm of compacted sub-base, laid in two lifts, each compacted properly, not tipped in as one loose heap and driven over. On clay, which holds water and moves with the seasons, you’d go deeper and add a geotextile membrane at formation so the stone can’t slowly punch into the wet ground. Much of the ground round here sits on clay with flints, so that’s no theoretical point here.

All that digging makes spoil, and spoil has to be carted away. Muck-away is often the line on a quote that surprises people. A modest drive can fill several grab lorries. It’s honest cost, not padding. A contractor who barely digs out has kept the price down by leaving the problem in the ground.

Choosing a surface honestly

Gravel is the cheapest to lay and drains naturally. The crunch underfoot divides opinion. Some people like hearing a car arrive. It migrates, though: expect to rake it back and top it up every few years, and it’s a poor choice on a slope. It lives or dies by its edging.

Block paving suits a period frontage and has one quietly brilliant property: if a pipe under the drive ever needs attention, the blocks lift and go back down without a scar. The jointing sand wants re-topping, and weeds will try the joints. Fully permeable versions exist. Worth asking about.

Resin-bound gravel gives the cleanest, most contemporary finish. Smooth, no loose stone, permeable when laid over an open-graded base. It’s also the least forgiving of what sits beneath it: resin over a weak base mirrors every fault, with no tidy local repair the way blocks allow. Ask about the resin itself, too. Cheaper ones yellow in sunlight.

Tarmac is the honest workhorse. Quick to lay, tough, and usually the sensible answer on a long drive where the square metres add up. It isn’t permeable unless specified as an open-graded mix, and wheels turned on the spot in a heatwave will scuff it.

Almost everything that decides how long a drive lasts is buried by the end of the first week.

The rules on water

England has rules about front gardens, brought in after years of paved-over frontages sending rain straight onto the road. The test is a narrow one and worth getting the right way round. Lay an impermeable surface over more than five square metres of front garden, meaning the ground between the front wall of the house and a highway, and you need planning permission, unless the run-off is directed to a permeable area within your own boundary. Replacing an existing surface counts towards that five square metres, not just laying a fresh one.

So there are two ways to stay inside permitted development. Build the surface so water passes through it. Gravel, permeable block paving, an open-graded resin or asphalt. Or lay something solid and fall it into a lawn, border or other permeable ground inside the plot. What doesn’t work is falling a solid surface towards the road and hoping nobody notices.

The detail shifts and the exceptions matter. Conservation areas, listed buildings, Article 4 directions, estates with planning conditions of their own. So put it to your local planning authority before anything is ordered. Be careful what you take from that conversation, though. A planning officer will give you a view on the phone or by email, and that view is informal. It doesn’t bind the council and it won’t stop enforcement later. The only answer you can rely on is a lawful development certificate: you apply, the council decides, and if it’s granted you hold a legal document saying the work is lawful. On a driveway it’s a modest application. It is also the difference between somebody’s opinion and something you can hand a buyer’s solicitor in ten years’ time.

Permeable on clay: the honest version

There’s a tension in all of the above that driveway sales patter tends to skate over. The way out of the planning rule is to let the water soak into your own ground. Much of the ground round here is clay, and clay soaks up very little. A soakaway dug into stiff clay can sit full for days after a storm and then back up over the ground it was meant to protect.

Permeable construction still works on clay. It just stops being a soakaway and becomes storage. The open stone under a permeable drive holds a fair volume of water in the gaps between the pieces, and where the ground won’t take it, that layer is lined and given a controlled outlet. Water is held through the downpour and let out slowly afterwards, at a rate agreed with whoever owns the pipe or ditch it ends up in. Where the ground takes some but not all, you get a bit of both: partial soakage with an overflow for the days it can’t cope.

What matters is that somebody works it out rather than assumes. As a rule of thumb, ask for a soakage test on the actual plot before any drainage design is settled. The standard method is BRE Digest 365. Clay varies from one end of a garden to the other, and a test pit costs a fraction of a drive that ponds. Connecting surface water to a public sewer isn’t automatic either: you have to notify the sewerage undertaker first and they can refuse. Your drainage engineer, and the local authority in its flood-risk role, will confirm what your plot actually allows.

Getting the car across the footway

A drive is no use if you can’t legally drive onto it, and this is a separate consent from everything above. Different law, different department, sometimes a different council altogether. Where a car has to cross a footway or a grass verge to reach your property, that crossing is made under section 184 of the Highways Act 1980 and the licence comes from the highway authority. In a unitary or London borough area that’s the same council. In a two-tier area it’s the county, not the district that handles your planning. On some main roads it’s a different body again. Planning permission and a dropped kerb are two consents, and holding the first gets you nowhere with the second.

Planning permission comes into the crossover separately, and it turns on how the road outside is classified. Forming a new access onto an unclassified or private road is generally permitted development where it goes with the drive itself. Onto a classified road, meaning an A, B or C road, it isn’t, and a planning application is needed as well as the highway licence. Your council can tell you which yours is. Ask early: it’s the one question that can change the shape of a drive after the drawings are done.

The highway authority then judges the crossing on its own terms: sightlines, footway width, street furniture, gullies, whether there’s room to pull off and turn rather than reverse out blind. It can say no. As a rule the works are carried out by the authority or by a contractor approved by it, to its specification, and the householder pays. Fees and waiting times vary a good deal between authorities, so ask yours before you fix a start date with anyone.

Edges, falls and gullies

Every surface needs restraint at the edges: gravel spreads, blocks creep, resin needs a firm edge to finish against. A proper edge course is bedded on concrete and haunched behind. That is the difference between a drive that holds its line and one that slumps at the borders.

A drive must also shed water: a gentle cross fall, around 1 in 60 to 1 in 80 as a rule of thumb, always away from the house. Where a drive runs down towards a garage, a channel drain across the threshold catches the water before the door does. That water must go somewhere legitimate. A soakaway where the ground will take it, otherwise whatever outfall the drainage design settles on, and never quietly into the foul drain, a building-regulations matter in its own right.

How the job should run

When the quotes come in, read them against that sequence. The cheap one has usually saved its money below the formation level, where you’ll never see it. Until you do. There’s a companion piece on reading a groundworks quote if you want the same honesty applied to the paperwork.