Plan, Elevation and 3D Shadow Diagrams: What Is the Difference?

Shadow Diagrams

Shadow diagrams can be presented as plans, elevations or three-dimensional views. These formats do not necessarily represent different shadow assessments. Instead, they provide different ways of viewing the modelled shadow condition, with each format making particular spatial relationships easier to understand.

In Brief

A plan shadow diagram shows the shadow from above and is useful for understanding where it falls across the site and surrounding land. An elevation shows the shadow in relation to vertical building geometry, while a 3D view provides a more spatial representation of the development and its context. The appropriate format depends on what the assessment needs to communicate and the documentation requirements applying to the project.

What is the difference between plan, elevation and 3D Shadow Diagrams?

The main difference between plan, elevation and 3D shadow diagrams is the viewpoint from which the modelled condition is presented.

A plan view looks down on the site from above. This makes the relationship between the development, property boundaries, surrounding buildings and horizontal shadow extent relatively easy to see.

An elevation presents a vertical view from a nominated side or direction. It can help communicate the relationship between the shadow condition and vertical elements of the built form.

A 3D view presents the development and surrounding context spatially, making the relationship between building form and shadow more visually intuitive. Which format is appropriate depends on what needs to be demonstrated rather than one format being universally better than another.

What does a plan Shadow Diagram show?

A plan shadow diagram presents the site from above. The proposed development can be shown in relation to the subject site, surrounding buildings, property boundaries and the shadow extending across the plan.

This viewpoint is particularly useful for understanding the horizontal extent of shadow. It allows the reader to see whether the modelled shadow remains within the subject site or extends across other parts of the represented context.

Plan views can also make it relatively straightforward to compare drawings prepared at different times or to distinguish between existing and proposed shadow conditions where those conditions are represented graphically.

The information shown around the shadow remains important. Site boundaries, orientation, assessment date and time, relevant building outlines and clear graphical conventions provide the context needed to interpret the plan correctly.

The shadow condition may be the same, but the view changes what is easiest to understand. Plan views emphasise where shadow falls across the site, elevations show the vertical relationship, and 3D views provide spatial context.

What does an elevation Shadow Diagram show?

An elevation shadow diagram presents the relevant built form from a vertical viewpoint rather than from above. Depending on the purpose of the drawing, this can make vertical relationships easier to understand.

Building heights, façades, walls and other vertical elements can be read differently in elevation than they can in plan. Where the assessment needs to communicate how shadow relates to a vertical surface or building form, an elevation may provide useful additional information.

An elevation does not replace the horizontal information available in a plan. Property boundaries and the extent of shadow across land are generally easier to understand when viewed from above, while an elevation can clarify a different spatial relationship.

Whether an elevation is required or useful depends on the project, the assessment purpose and the documentation requirements that apply.

What does a 3D Shadow Diagram show?

A 3D shadow diagram presents the modelled development and shadow in a spatial view. Instead of reducing the site to a purely horizontal or vertical projection, it allows building mass, surrounding context and shadow to be seen together.

This can make the drawing more intuitive for readers who are less familiar with architectural plans and elevations. The relationship between a proposed building and the shadow it casts may be easier to recognise when the building form itself is visible three-dimensionally.

A 3D view can also help communicate more complex building forms or site relationships that are difficult to understand from a single flat drawing.

Greater visual realism, however, does not automatically make a 3D view more technically appropriate. The required drawing format still depends on the purpose of the assessment and the documentation expected for the project.

Do plan, elevation and 3D diagrams calculate different shadows?

Not necessarily. Plan, elevation and 3D diagrams can be different representations of the same underlying modelled shadow condition.

If the same development geometry, site orientation, assessment date and time are being represented, changing the view does not itself create a different solar condition. What changes is the way the information is presented to the reader.

This distinction is useful because terms such as “3D shadow diagram” can sound like a separate type of shadow assessment. In practice, a three-dimensional image may simply provide another view of the same model used to prepare plan-based documentation.

The reliability of the represented shadow still depends on the underlying project information, geometry, orientation and assessment conditions rather than on the visual format alone.

Why are plan views commonly used for Shadow Diagrams?

Plan views provide a direct way to relate the modelled shadow to the layout of the site. The development footprint, subject site boundaries, adjoining land and surrounding buildings can all be represented within the same horizontal view.

This makes plan diagrams particularly effective for showing where a shadow falls geographically in relation to the represented site context. A sequence of plans can also make the changing shadow position at different assessment times relatively easy to compare.

Existing, proposed or additional shadow conditions can also be distinguished within a plan where the drawing conventions allow them to be identified clearly.

The usefulness of a plan still depends on the information around the shadow itself. What Should a Shadow Diagram Show? explains the drawing elements that help establish the represented condition and site context.

When can an elevation view add useful information?

An elevation can add useful information when the vertical relationship between the development, shadow and surrounding built form needs to be communicated more clearly.

A plan is effective at showing where shadow extends across a site, but it compresses vertical building geometry into a view from above. An elevation presents that geometry differently, allowing heights and vertical surfaces to be seen more directly.

This can be useful where the vertical relationship itself is relevant to understanding the documentation. It does not mean that every shadow assessment needs an elevation or that an elevation is more informative in every situation.

The view should be selected because it communicates information required by the assessment, not simply because another graphical format is available.

Why can 3D Shadow Diagrams be easier to understand?

Architectural plans and elevations use drawing conventions that may be unfamiliar to someone who does not work with them regularly. A 3D view can reduce some of that abstraction by showing the building in a form that is closer to the way it is understood spatially.

The reader can see the proposed building mass, neighbouring context and modelled shadow within the same image. This can make it easier to understand which part of the development is associated with the represented shadow and how the site fits together.

That visual accessibility comes with a different emphasis. Perspective and viewpoint can make some spatial relationships less directly measurable or comparable than they are on a scaled plan or elevation.

For this reason, a 3D shadow view can be valuable as a communication tool without automatically replacing the technical drawings required for the assessment.

Does a 3D Shadow Diagram replace a plan or elevation?

Not necessarily. A 3D shadow diagram and a technical plan or elevation serve related but different communication purposes.

A three-dimensional view may make the overall spatial relationship easier to understand, while a plan can provide a clearer horizontal reference to site boundaries and surrounding land. An elevation may communicate vertical relationships that are less obvious from either of those views.

If particular drawing formats are required as part of planning or project documentation, a visually detailed 3D image should not be assumed to satisfy those requirements simply because it contains the same modelled building.

The appropriate documentation should be established from the requirements applying to the project and the information the shadow assessment needs to demonstrate.

Can different Shadow Diagram views be used together?

Yes. Where useful or required, different views can complement one another because each format emphasises a different part of the spatial relationship.

A plan can establish where the shadow falls across the site. An elevation can provide additional information about the vertical relationship. A 3D view can then help communicate how the development, surrounding built form and shadow relate spatially.

Using several views does not necessarily mean that several different shadow conditions are being assessed. They may simply be different representations of the same nominated date, time and development scenario.

Equally, not every project benefits from every format. Additional drawings are useful when they clarify something relevant to the assessment rather than simply repeating the same information from another viewpoint.

Which Shadow Diagram format does your project need?

There is no single shadow diagram format that should be assumed to suit every project. The appropriate view depends on the assessment purpose, project geometry, site context and documentation requirements that apply.

For some projects, plan-based diagrams may provide the information required. Others may benefit from elevations, 3D views or a combination of formats where additional spatial relationships need to be communicated.

The choice should therefore begin with what the documentation needs to demonstrate rather than with a preference for a particular visual style.

Checking the project requirements before preparing the drawing set can help ensure that the selected views provide the necessary information without adding unnecessary or duplicative documentation.

Different views within the wider shadow assessment

Plan, elevation and 3D shadow diagrams are different ways of communicating spatial information from a shadow assessment. Their value lies in what each view makes easier to understand.

Plan views emphasise the horizontal relationship between the shadow, site and surrounding land. Elevations can clarify vertical relationships, while 3D views can make the overall building and shadow relationship more intuitive.

These views can be complementary rather than competing. The most appropriate documentation is the combination that communicates the required shadow condition clearly and satisfies the requirements relevant to the project.

The representation may change from plan to elevation to 3D, but the underlying purpose remains the same: to make the modelled shadow condition understandable in relation to the development and its context.