How an outdoor space is built

Building an outdoor space means coordinating ground, drainage, structures, services, materials and planting. Planting is an important stage, but it depends on everything that has been built before it.

At Diaplant, the build can take in ground modelling, walls, paving, irrigation, lighting, water features, planting and aftercare. Managing it all together reduces conflicts between disciplines.

The build starts with setting out, protecting what is to stay and organising access. Existing trees, soils to be retained and storage areas are marked.

The design, the applicable permits and the safety conditions are also confirmed.

Ground modelling establishes levels, falls and platforms. Cut and fill are controlled so as not to create unstable areas or block drainage.

Topsoil is set aside when it is of good quality and protected from compaction.

Drainage, irrigation, electrics, lighting and underground services go in before the finishes. Runs and boxes are coordinated with trees, walls and paving.

Their location is recorded before they are covered.

Foundations, retaining structures, walls, steps, paving and decks are built. Each material needs a suitable base, joints, edge details and run-off.

Finished levels are checked continuously. A small error can create uncomfortable steps or leave water against the house.

Pools, ponds, pumps and plant rooms are tied in with levels and maintenance access.

Waterproofing and the overflow need to be resolved before the surface finishes go on.

After the heavy stages, the soil is decompacted and prepared. It should not be treated as a route or a storage area before planting.

Drainage, organic matter and soil profiles are adjusted zone by zone.

Large specimens go in while access and the crane are still possible. The planting hole, the equipment and the team are made ready before arrival.

Orientation and level are confirmed against the design.

Planting follows the layers and densities. Positions are set out on the ground, adjusting small differences without losing the composition.

Initial watering, mulching and finishing are carried out straight after each area.

Services are tested, and drainage, finishes and stability are reviewed. The client receives instructions and a maintenance plan.

The build is physically finished, but the planting is starting its establishment period.

In the first few months, watering, staking and settlement are corrected. The garden is assessed in real use and not just on handover day.

Trees, walls, paving and services that are to stay should be protected before any excavation. With a tree, protection does not stop at the trunk: the soil and the roots cannot be used as a site compound, a parking area or a storage zone.

Existing vegetation is recorded before work starts. When an unforeseen root or service turns up during excavation, work should stop at that point and the change be decided on the basis of the design, rather than being settled solely by the team that found the obstacle.

Some work needs to be inspected before it is hidden. Buried services are tested and photographed; levels and falls are confirmed before the finishes; waterproofing and bases are checked before the surface goes on.

These checks avoid discovering a fault when putting it right already means demolition. The record also makes it possible to produce as-built drawings that are useful for maintenance.

On handover day, materials and plants are at different stages. The stone and paving already show much of the result; the planting is only beginning to establish.

The space should be built to accept growth, leaf fall, maintenance and small adaptations. A well-built outdoor space is not just what looks finished in the final photograph, but what still works when the garden starts to mature.

An outdoor build brings together teams working at different paces. Earthworks, structures, electrics, plumbing, paving and planting need to work to the same levels and the same version of the design.

Site meetings should settle decisions before each stage is covered up. When an unforeseen service or soil condition appears, the change is recorded and assessed as a whole. Moving a box can affect a tree; changing a level can alter drainage, steps and quantities.

The soil in the planted areas is reviewed once machinery has stopped moving around the site. Even ground prepared at the start can become compacted during the build.

Decompaction, corrections and final modelling are carried out before planting. After that, the beds are no longer used as a route or for storage. This change of phase is essential if the roots are to find a working volume of soil and not a layer of topsoil over a hard base.

• Diaplant design and construction method.
• Good practice in landscape construction.