Creating Functional Areas
No matter how stunning your garden, it will be a constant source of frustration to you if your steps are too steep, your patio too small or your paths are too narrow. Planning your garden and working accurately to scale means you can work out how big all your features can eventually be, and amend them as necessary.
However, working ergonomically - that is, making sure that each space performs the function it is designed for - relates to more than just the size of the spaces. Thinking about how the garden will be enjoyed and used is all part of garden design. If you intend to build a pond, is there somewhere to sit, relax and watch the fish? If you have planned your compost heap in a particular place, can you access it easily, without, for instance, wearing bare patches in a lawn?
We've put together some size guidelines to help plan all your garden features. However, you'll need to remember that planting will form a part of your final garden design, and may affect access around the garden. For example, a path edged with plants spilling over on to it must be at least 25 cm (10 in) wider than a simple path edging a boundary or lawn. Planting areas also need to be planned for easy maintenance. Narrow borders will force you to plant in a single straight line, which is undesirable if you want to create appealing planting schemes. They will tend to dry out quickly too. On the other hand, you may need to put a path through very wide borders to enable you to maintain and prune the plants at the back.
You will also need to consider your boundaries as an important part of the overall design. Make sure that any walls are thick enough for their height, and allow extra space in front of any hedges to enable you to maintain and clip them.
By following these space guidelines, you will be able to create a garden that looks and works in exactly the way you want.
Barbecues and Work Tops
The height of these can vary slightly depending on personal choice, but should be between 75-85 cm (30-33 in). Position carefully in relation to sun, wind and neighbours.
Boundaries
Walls can cast rain shadows on beds beneath them. Hedges planted at the backs of borders need to have 30 cm (1 ft) access behind the planting for maintenance, clipping and so on.
Lawns
Lawns need to be in sun or light shade, and the seed mixture or turf should be chosen accordingly. It's a good idea to construct a mowing edge to your lawn from brick or other frost-proof material.
Pergolas and Arches
These should always be high enough for adequate head clearance, remembering that climbers will also take up head room: 2.1 m (7 ft) is a good average. They should be generously wide with their posts a minimum of 45 cm (18 in) from the edge of a path.
Paving
The minimum size for a patio or terrace is 3.6 x 3.6 m (12 x 12 ft). This will give you enough space for a modest-sized table and four chairs.
All surfaces should be at least 2 courses of brick below the house damp proof course (15 cm or 6 in).
Paving should fall gently away from the house (not less than 1:100) to avoid water running towards the foundations of the house.
Paths should be no less than 60 cm (2 ft) wide. If you need access for wheeled toys and barrows, just less than 1 m (3 ft) is better.
Ponds
The average garden pond does not need to be more than 60 cm (2 ft) deep, with marginal shelves 22 cm (9 in) below the surface. Shelves should be approximately 30 cm (1 ft) wide.
Pools should be positioned in full sun for water plants, but away from deciduous trees that will drop leaves into the water.
To calculate the area of a pond liner, add the maximum width and length of the pool to twice the maximum depth. Take a look at our article on building a pond with a flexible liner for more details.
Seating
Built-in seats, raised beds used as seats, and seats around trees should be approximately 45 cm (18 in) high.
Steps and Ramps
Ideally, steps should have a riser height of 15 cm (6 in) and a tread of 45 cm (18 in). Calculations to find the right tread:riser proportion may be found here...
The maximum gradient of a ramp should be no more than 1:10, or you will find them tricky to negotiate in icy weather or with heavy barrowloads.