Habitat Theory

Click thumbnails for a detailed view

freewayParkPlanting.jpg (77694 bytes)

eFacingTerrace2web.jpg (145843 bytes)



Jay Appleton proposed a habitat theory of landscape aesthetics in The Experience of Landscape. His concept is that the evolutionary heritage of man shaped our appreciation of certain landscape characteristics above others. Appleton suggested that natural symbols that suggest an abundant and benevolent habitat were selected over others. Studies of birds that select territory based on the presence of certain species of plants support his view. Indicator species of plants were used to suggest future food abundance.

Similarly, the use of ornamental plants in human landscape may be regarded as natural symbols suggesting an abundant habitat. You may wonder why ornamental plants rather that food producing plants are the most common plants near human habitations. The explanation may be that food producing species attract animals and insects that threaten the comfort of the place.



ghiradelli.jpg (102105 bytes)


visual prospect.jpg (31526 bytes)Other natural symbols of a positive or supportive landscape are places of prospect and refuge, according to Appleton. Places of prospect are those from which one can view the landscape. Presumably, being able to see animals or other people before they could see you was a desirable evolutionary situation. Of course, being on a summit or plateau edge overlooking a valley is a prospect situation but so are more subtle situations such as viewing well lighted objects.

The the drawings in this page are from Motloch, Introduction to Landscape Architecture


No Refuge.jpg (12255 bytes)

Lack of Refuge

Bar-terrace, Turku.jpg (115172 bytes)



Conversely, man seems to prefer environments in which he can remain unseen by others. These are refuge places. They are on the edge of open spaces or enclosed spaces or, more subtly, places that are shaded rather than in full sun.

Prospect and refuge.jpg (55056 bytes)

Prospect and Refuge

Describe a situation in which prospect and refuge symbols are combined in a single place.

The optimum circumstance is a place where one has a commanding view of the landscape but can not be seen by others.

iras.jpg (42687 bytes)


iras.jpg (42687 bytes) Discuss this image to illustrate Jay Appleton's Habitat Theory of landscape aesthetics? 

A final aspect to habitat theory is the concept of hazard. Man prefers stimulation and some level of risk in the environment. Venturing into the unknown can have a positive evolutionary impact. It can provide information that might prove vital to survival at a later time. This behavior might be explained by the study of animals who make short and then longer forays from their burrows. They gain information about alternate escape routes that could save their lives in the future.


Architecture and the Formation of Exterior Space



Buildings may be regarded as sculptural objects but simultaneously each facade is a spatial edge.  This pages explores the use of architecture to define exterior space.


Degree of Enclosure

Whether buildings or landscape elements define a space the degree of enclosure is important to the character of the space.

Minimally enclosed.jpg (23817 bytes)

monumentalScale.jpg (64300 bytes)


Vertical closure of the sight line is important in defining space.  The height of the vertical plane and its distance from the view are important in establishing the degree of enclosure.  If the distance to height ratio is 4 to 1 or greater, then there is no sense of enclosure.  The vertical edge is simply perceived as a detail in a larger landscape.  At a 3:1 ratio a sense of minimal enclosure is perceived, although the edge of the space is clearly defined.


Partially enclosed.jpg (16683 bytes)

Partial Enclosure

Of course, the vertical plane must be taller than a person if the sense of enclosure is to be very effective, especially if the privacy or blocking objectionable views is the design goal.  Vertical planes below eye level subdivide larger spaces.


Fully enclosed.jpg (19119 bytes)

patio.jpg (134060 bytes)

Full Enclosure

In which situation would a space feel unenclosed, partially enclosed and fully enclosed?  Express your answer in terms of horizontal to vertical ratio.

When the horizontal and vertical dimensions are equal a sense of full enclosure is imparted.

Building sculpture.jpg (68159 bytes)

Describe a situation in which two facades of a single building might be designed to express very different characteristics (materials, color, stylistic elements).

Buildings are often regarded as sculptural objects, especially by the designer and owner.  In this view, the character of each facade is subservient to the sculptural idea.  However, in an urban context buildings often form the vertical edge of at least two spaces.  This view of a building suggests that the space and the character of the facing buildings should influence the character of each facade.


Spacial Definition.jpg (46019 bytes)

grilledOpeings.jpg (70116 bytes)

When buildings enclose space, the arrangement, height and proximity determine the sense of enclosure that they impart to the user.  In this image, the top diagram illustrates building edges that incompletely enclose exterior space because the space leaks out of large gaps between them.

While there are gaps between the buildings in the lower diagram, a more clearly defined volume exists.  However, from some locations within the volume, one would sense a lack of enclosure due to the lack of a vertical edge on the left.

The vertical edge can be pierced or implied to enclose a space to a certain degree while giving visual or physical access to another space.


Link elements.jpg (19475 bytes)

Define what architectural use of plants means.

When there are gaps between buildings, plants or garden walls can link the architectural elements to form the spatial volume.  Notice that in this image that the buildings are too small and poorly arranged to enclose space well.  The addition of plant arranged as architectural elements establishes major, alcove and circulation spaces.


Arch edge.jpg (61728 bytes)

Plants can be treated as sculptural elements or masses just as buildings can.  They are used architecturally when their purpose is to define spatial edges and establish a volume.


Degree of enclosure.jpg (59186 bytes)

Degree of Enclosure

laplaza.jpg (67749 bytes)

Enlarge and study this diagram.  It illustrates the degree of enclosure established by several arrangements of buildings.  Note that the location of buildings also imparts a directionality to the spaces.  Long narrow spaces establish this sense of direction most strongly.

Notice that whether or not the sight line is terminated at a building impacts the degree of enclosure, especially when approaching the space.


Aligned approach.jpg (54165 bytes)

Axial Exits


static space.jpg (95977 bytes)

Blocked Sight Lines

Draw a plan view diagram of a whirling square.  Describe its attributes.




Whirling Square

In the top plan and perspective, the buildings form an almost completely enclosed space.  However, because the entrances and exits of the space are aligned the sightlines extend through the space to terminate in the landscape outside the space.  This diminishes the importance of the space and its sense of enclosure from the entrances.  It emphasizes the circulation route through the space and the larger landscape.


In this diagram, the sight line from every entrance to the space is terminated at a building.  Therefore, the space seems completely enclosed as one enters.  This type of space is often called a whirling square because of its pinwheel pattern.

The facade of the buildings are of great importance since they are experienced frontally rather than from an oblique point of view.


D space with alcove.jpg (125502 bytes)


501048.JPG (49611 bytes)Variations in the facade or the arrangement of the buildings can deliberately create subspaces within the larger space.  This is the beginning of the development of a complex hierarchy of spaces that can serve a variety of purposes.


space dominant.jpg (123479 bytes)

Because of the complete enclosure of this volume, the orientation of the user is inward.  The building facades dominate the space and determine its character.


Mass dominant.jpg (73492 bytes)

Since space is only partially enclosed by this complex of buildings, the orientation is outward from many locations within the volume.  The elements in the more distant landscape can influence the space and the direction of circulation.


Sequential space.jpg (108155 bytes)

Which type of space most strongly expresses directionality?

A series of spaces can be developed by the careful design of building shape.  These can be characterized as arrival, directional or alcove spaces.  Notice the alternation of expansion and compression of the volume.  It induces pooling activity or circulation.


Mass space.jpg (83542 bytes)

Draw four buildings in plan view.  Shape them to define and enclose two major spaces, two secondary or alcove spaces and one directional space.


This diagram illustrates a dynamic interplay between mass and space.



Form Making

squareWOblisk.jpg (113889 bytes)


pershing.jpg (103589 bytes)

The design of site elements is to serve the use of people. Users seek evidence of rational order or meaning in the design of landscapes and buildings. The absence of a discernible idea or ordering system is often regarded as unharmonious or ugly. To impart a discernible purpose and order to a design geometry and proportioning systems are often adopted to generate physical forms.

Geometry is a powerful generator of physical form. Rectangular, angular and circular geometry singly or in combination are used by designers to organize the designed environment.

Rectangular geometry is common to architecture due to construction economy. However, the vertical and horizontal lines of the two and three dimensional elements are resolved according to laws of gravity. The vertical and horizontal lines are stable not dynamic. A great deal of unity is imparted to the composition which can become predictable and monotonous.


Generative forces.jpg (46889 bytes)

The web site illustrates a method of generating an angular composition of lines and edges that imparts a sense of rational order on the composition.  What is the method?

RecRadials.jpg (117619 bytes)

Angular geometry depends on points, radial lines and angles to establish a more complex and dynamic composition. The source of the angular lines can be arbitrary and result in a confusing composition. A method of controlling the angular composition is to generate all lines and edges from one or more points within or outside of the composition. This imparts a sense of rational order on the composition.


Circular shapes.jpg (49041 bytes)

What are the three components of circular geometry?

circles.jpg (89001 bytes)

yerbaBuena.jpg (50403 bytes)


Circular geometry is based on lines revolving around points. The generating point, the arc and radial forces confer a rational order to the composition especially when a series of elements share some of these fundamentals of geometry.
curvesRect.jpg (185132 bytes)

pioneerSq3.jpg (80902 bytes)

Often different geometric forms are combine to create tension and dynamic designs.