What a garden concept design includes

The concept design turns the briefing and the site analysis into a spatial proposal that can be understood, discussed and changed.

It does not yet contain all the details needed to build. It should, however, define layout, scale, main levels, the language of materials and the planting structure clearly enough for decisions to be taken.

The stage ends when there is an approved scheme to take forward, and not just a set of images.

The plan shows routes, seating areas, access points, pool, water, structural planting and the relationship with buildings.

The scale should make it possible to read measurements and distances. Generic shapes with no dimensions can create an idea that is pleasant and impossible to build.

The plan distinguishes between what exists, what is proposed and what is to be removed.

It also shows orientation and the limits of the work.

The concept explains the principles that organise the space.

It may connect indoors and outdoors, work with the topography, reinforce a rural landscape or create a sequence of settings.

The text should be tied to the decisions. Abstract expressions with no consequence in the design do not help to assess the proposal.

The concept is there to compare alternatives and keep things coherent through the detail.

Each area is given a function or a degree of flexibility.

The proposal shows how people move around and how the uses relate to one another. A dining area needs a link to the house, shade and support space. A kitchen garden needs sun, water and access.

Transitional spaces are designed too, avoiding a collection of disconnected compartments.

The main terraces, steps, ramps, walls and banks are identified.

At this stage the levels can still be adjusted, but the feasibility must be real. A design that ignores the change in level can change completely when it reaches the detailed design.

Schematic sections help to show relationships that the plan does not.

The cut-and-fill balance and the retaining structures start to influence the estimate.

The concept design presents families of materials, references and principles for their use.

There is no need to settle on every brand, but character, performance and the relationship with the architecture should be defined.

Stone, timber, concrete, gravel and other materials are assessed together, avoiding too broad a palette.

Drainage, slip resistance and maintenance are part of the selection.

The structure is defined: trees, large shrubs, masses, herbaceous layers, lawns, meadows and productive areas.

The main species can be named, especially when they determine the image or the feasibility.

The detailed planting plan, the spacings and the quantities are normally left for the next stage.

When mature trees are used, realistic sizes and forms can be shown. A mature crown should not be drawn if the budget provides for very young stock without explaining the time involved.

Pool, pond, watercourse, drainage and irrigation are shown as an integrated whole.

The position takes account of sun, wind, views, levels and technical access.

The concept design should indicate the general type of system. A natural swimming pool is not simply a conventional pool with plants, and it needs specialist sizing.

A lighting strategy can be presented: routes, trees, façades and seating areas.

Circuits and fittings are not necessarily fixed yet, but effects that are incompatible with the design are avoided.

Comfort, glare and the relationship with wildlife are part of the proposal.

Moodboards, 3D models, renders and video help to convey atmosphere and scale.

They should stay consistent with the plan and with the sizes at planting.

The image should not hide walls, equipment or limitations that will be visible on site.

Several angles make it possible to compare the experience and not just choose the most flattering view.

The concept design is checked against the financial framework.

The areas of paving, retaining structures, water, infrastructure and plant size all have an impact.

The estimate at this stage includes assumptions and a margin of uncertainty. It becomes more accurate at detailed design.

If the scheme exceeds the framework, priorities or phasing are adjusted before detailing.

The garden can be built in stages, but each of them needs to work.

The first phase prepares levels, services and access so that work is not destroyed later.

Trees and structural elements can go in early, while other planting and finishes are left for later.

Phasing should not leave areas without drainage or maintenance.

The concept design identifies elements that may require a formal procedure: walls, pools, structures, ground modelling, access points and impermeable surfacing, among others.

The analysis depends on the PDM (municipal master plan), the constraints and the legal regime in force.

The proposal may need adjusting before it goes forward to the planning application documents.

The client receives enough information to comment on decisions and not just choose images.

Changes are recorded and assessed together. Moving a pool can change levels, views and investment; it is not an isolated move.

The stage ends with an approved version and with the matters still to be resolved identified.

Unless specifically commissioned, the concept design is no substitute for construction details, specialist engineering calculations, full measured quantities or site supervision.

This distinction should be clear in the fee proposal.

The value of the concept design lies in taking the decisions with the greatest impact while they are still simple to change.

• How a project is developed
• From sketch to video
• Detailed design

1. Principles of project phasing in landscape architecture.
2. Diaplant’s method for concept design and visualisation.
3. RJUE (Portugal’s legal framework for urban development and building) and the territorial planning instruments applicable to each project.