Three ways to deck a slope
There is no single right answer. The shape of the garden and what you want to do in it decide which layout makes sense.
- One raised deck at house level. Best when the back door opens onto the drop. You step straight out onto a flat floor, and the space under the deck takes the bins and the mower. It is the most expensive per square metre because the frame is tallest at the far edge.
- A split-level deck. Two platforms, usually 40 to 60 cm apart, joined by a wide step. Each frame stays lower, which can keep both under the 30 cm planning limit if the ground is stepped first, and the garden feels less like a balcony.
- A deck at the bottom, steps down to it. For gardens that rise behind the house. A level deck goes on the flattest part, with a path or steps up. The frame stays low and cheap; the cost moves into the steps.
Planning: the 30 cm line
Under the national permitted development rules, a deck or platform in a back garden does not need planning permission as long as no part of it is more than 30 cm above the ground, and together with extensions and outbuildings it covers no more than half the garden.
On a slope that 30 cm is measured from the ground directly beneath, so the far end of a deck taken out level from the door is usually well over it. That means a raised deck on a falling garden normally needs a householder planning application to Bradford Council. A split-level design can sometimes stay inside the limit, which is one reason it is popular here.
Raised decks can also look straight into next door. Councils weigh up overlooking when they decide, so a privacy screen on the side facing a neighbour helps an application.
Why composite suits a Bradford slope
A sloping deck is often half-shaded by the house and the bank, and Bradford is wet for much of the year. Timber in that spot goes green and slippery within a couple of winters. Capped composite boards shrug off algae far better, need a wash rather than a stain, and do not splinter on the stairs.
The frame matters as much as the boards. On a tall deck, ask for treated joists rated for ground contact, or aluminium joists, and posts on concrete pads rather than in the soil.
How long it takes
A simple deck on pedestals over a gentle fall is two or three days. A raised deck on posts usually takes four to six, because the footings need a day to go off before the frame goes on. If planning permission is needed, allow eight weeks for the council to decide before work starts.