Chapter 12 – Landscape Drawings & Specifications

Understanding Drawings

Contract document drawings can be divided into two major categories. The first category contains views of the project as if it were being viewed from high in the sky overhead. These are two-dimensional drawings that look like maps and are called plan views.  The most important plans in landscape work are the layout, grading and planting plans. (Figures 1, 2, 3)

Figure 1. Sample plan view Layout drawing.

Figure 2. Sample plan view Grading and Drainage drawing.

Figure 3. Sample plan view Planting Plan drawing.

The second category is composed of two-dimensional drawings that present the project viewed from the side in a horizontal and vertical dimension. A side view is called an elevation view, a cut-through side view is called a section view. Small drawings that are often section views (but may be plan views) of specific project elements showing how they are to be constructed are called detail drawings. Detail drawings are the most important type of elevations or sections in landscape work. (Figure 4)

Figure 4. Sample sheet of Detail drawings.

A third minor category of drawings is made up of three-dimensional views, called perspective drawings. They are often used to communicate design ideas early in the design process, but seldom are included in contract documents. When they are it is usually as a detail.

Common Elements Found on Most Drawings

Title Block

Common to all sheets of drawings for a project is a collection of information called a title block (Figures 5, 6). It normally contains:

• sheet name
• sheet number or letter/number combination (this may indicate how many drawings there are in total in a complete set, i.e. 7 of 10)
• project name
• project owner’s name
• the design office that prepared the drawings (name and contact information)
• the legal stamp of the design
  • professional who did the design (if required by law)
• initials of those who actually prepared
  • the drawing
• date of drawing preparation
• date(s) of revisions

Figure 5. Sample Title Block, vertical.

Figure 6. Sample Title Block, horizontal.

Scale, North Arrow & Legend

Drawing sheets typically display the scale at which the drawing is made. For orientation on plan drawings, a north arrow is shown, too.(Figures 7, 8) The scale is usually stated in text and numerals and also shown graphically. In the case of several separate drawings on a page (such as a sheet containing numerous details) there may be several different scales indicated. Occasionally, a drawing may be labeled with dimensions of objects, or no dimensions, but lack precise graphic accuracy. Such drawings are generally indicated as “not to scale.”

Figure 7. Sample North Arrow with graphic scale.

Figure 8. Sample North Arrow with text scale.

A list of symbols used in the drawing and their meanings is usually provided, called a legend.(Figures 9, 10) A clearly presented legend is essential to understanding the intent of a drawing. Finally, various notes, comments or other text may be shown that help clarify or add understandability to the drawing.

Figure 9. Sample Legend from Demolition plan.

Figure 10. Sample Legend from Drainage plan.

Important Plans

Layout Plan

The layout plan deals with the horizontal dimensions of a site.  It shows the precise locations of proposed site elements in relation to one or more existing elements, or locations on, or adjacent to the site.  (See Figure 1 above)

The identification of the existing location or element as a starting point is fundamental because all dimensions arise from it.  It may be a surveyor’s benchmark, a building wall, the edge of an adjacent pavement, or any other existing, permanently fixed element.  The known point, or starting location for dimensioning must always be clearly identified on the drawing.  It is also important to find it on the ground prior to any on-site layout, or staking.

Several methods may be used to show locations on the plan. The simplest is a linear dimension from a known point to a readily identifiable point (usually a corner, edge, or center point) of a proposed element. The dimensions are often plotted in a due east-west, or north-south direction, or may be parallel to an existing edge. Angular shapes with other than square corners may be defined by degrees, or as otherwise indicated. (Figure 11)

Figure 11. Sample Layout – Dimension plan with distance and angular information.

For curvilinear forms, simple perpendicular dimensions are usually not adequate. For regular geometric curves such as circular arcs, a center point and radius may be given. (Figure 12) Irregular curves and shapes may be described by using offsets. These are linear dimensions plotted perpendicularly from measurable locations along a straight line. (Figure 13)

Figure 12. Sample Layout – Dimension plan with circular arcs.

Figure 13. Sample Layout – Dimension plan utilizing offsets.

Dimension lines showing the size of an element are not normally connected directly to the element for which they are providing the dimension. A projection line begins near the element being located and projects out to a part of the drawing where clearly legible dimensions can be inserted. Dimension lines are usually solid lines with arrows or slash marks on each end where they intersect the projection line. The dimension itself (numerical distance) is written just above the dimension line or the line is broken with the dimension inserted in the space. (Figure 14)

Figure 14. Dimension lines and distances.

The coordinate, or grid system is a comprehensive method of dimensioning. It sets up an imaginary rectilinear grid, usually with a north-south and east-west orientation. Proposed elements are located based on (X,Y) coordinates on the grid. The X and Y values are dimensions from two perpendicular base lines. The intersection of the two base lines is the origin, or (0,0) point on the grid. You can think of the grid method as if a piece of graph paper was laid over the site with, generally, the lower left hand (south- west) corner being the origin.(Figure 15)

Figure 15. Sample Layout – Dimension plan utilizing a grid with baselines A & B.

Stationing is another system of layout used for uniform linear site features such as roads, trails, or utility lines. A centerline is defined and measurements are indicated in 100-foot increments along its length. Layout by stationing requires technical surveying techniques and is seldom used in landscape planting projects.

In complex projects, a combination of layout systems may be used. Overall site layout may be based on coordinates, with secondary or more localized elements located via linear dimensioning, offsets, or center points and radii.

Grading Plan

The grading plan deals with the vertical and horizontal dimensions of a site; that is the shape of the land surface. This is commonly referred to as topography. The plan shows the location of proposed site elements and the vertical form (elevation) of all the land surfaces relative to a fixed point of known elevation. (See Figure 2)

Just as with layout dimensions, elevations are expressed relative to a known point. In grading, it is a point of defined elevation. This known point is called a reference point, datum or benchmark.(Figure 16) It may be a permanently constructed element just for the purpose of defining elevation (a brass plate in concrete set in the ground) or it may be as simple as a corner of a pavement or curb. It should be clearly called out on the grading plan and readily identifiable on the site. All elevations, or grades, on the site are figured relative to the elevation of the benchmark.

Figure 16. Example of Benchmark on grading plan drawing.

Elevations, or topography are shown on a grading plan either with topographic lines or as individual points. Often, both are used on the same plan. Topographic lines are lines that connect points of equal elevation at even intervals above the reference point or datum.

In landscape work, one foot is the most common topographic interval. Thus, there is a line for each one foot of elevation. Individual points are called out by their precise elevation, usually to an accuracy of one one-hundredth of a foot. These are called spot elevations. (Figure 17)

Figure 17. Example of spot elevations on grading plan drawing.

Grading involves making changes to an existing land surface resulting in an altered one. That may mean raising the grade or elevation (a fill) or lowering the grade or elevation (a cut). To show the necessary changes and illustrate how much soil must be added or removed, both existing and proposed topography is shown on a grading plan.

Typically, existing topography is shown by broken or dashed lines, while proposed topographic lines are solid. The elevation of each line is written next to the line, and always on the high, or “uphill” side. It is written so that the reader is looking up the slope when reading the elevation of the line.

Similarly, spot elevations are indicated as existing or proposed. Both are shown as numbers adjacent to a cross symbol (+) indicating the precise location of the elevation. A commonly used graphic technique shows a proposed spot elevation value in a box, while an existing spot elevation value has no box around it.

Individual plant symbols usually have a cross, a dot or an “x” symbol in the center indicating the actual location of the plant crown or main stem. They should be precise enough to allow the plant installer to use an appropriate

Planting Plan

The planting plan shows all the plants that are to be installed on a project. Symbols are used to represent different types of plants.

Locations are shown in the manner of a layout drawing, but dimensions are omitted. The plant list, a table summarizing information for all the plants shown on the plan, is typically presented on the sheet with the planting plan drawing (Figure 3).

Figure 18. Some typical symbols used on planting plans.

Many graphic symbols and devices are used to represent plants on a planting plan. Symbol size is usually representative of the size the plant will reach after several years in the landscape, not fully mature size. Large and medium-size plants are shown individually, while small plants used to create a mass effect are often shown as a uniform mass or group. A graphic texture may be used to define such an area. When mass planting areas are illustrated, information must be supplied for plant spacing and arrangement (rectangular grid, triangular grid, etc.) within the mass. Figure 18 shows some examples of symbols used to illustrate plants.

Individual plant symbols usually have a cross, a dot or an “x” symbol in the center indicating the actual location of the plant crown or main stem.  They should be precise enough to allow the plant installer to use an appropriate ruler (architect’s or engineer’s scale) to measure the correct location for each plant from the drawing. A symbol on a planting plan in a contract document set should never be so “artsy” that the precise intended planting location is obscured.

Labeling on a planting plan should be very thorough! There should be no guessing as to which plants are which. Every plant should have a label (either the plant name or code that relates to the plant list) attached to it directly, or it should be graphically connected to other similar plants in a group with the group clearly labeled. The best labels are those that indicate the quantity of plants covered by that specific label, as well as the plant name.

Figure 19. A typical Plant List from a planting plan drawing.

The plant list is a complete table of information about all the plants represented on the planting plan drawing.(Figure 19) For every type and size of plant used in the design, it gives a complete, accurate scientific name in correct form with the quantity, plant size and root condition required. A common name for each plant is generally included, too, although primary use should be made of the scientific name. There may be notes or comments about certain plants included in the plant list to further explain the design intent.

Complex projects with little room for labeling on the plan may require that a coding system be used to relate the plants on the plant list to the labels on the drawing.  Such coding may be necessary, but is usually difficult to use. Extra care should be exercised when reading planting plans employing a code system.

Plant quantities shown on the planting plan, taken together, should match the total of the same plants listed on the plant list. However, such is not always the case. Mistakes happen. It is generally held that the number of plants shown on the drawing is the correct one and is the actual number implied in the contract. Thus, it is not enough for a contractor to look only at the plant list when preparing a cost estimate, ordering stock, or when pulling plants to bring to a job site.  The drawing itself must be studied.

Detail Drawings

A detail drawing is a way of communicating how to install or build something when such communication is most successfully accomplished using a picture rather than text. A detail is drawn at a scale that allows every detail of construction or planting to be fully illustrated. Details are often cross section views (Figure 20) but may be “blow-ups” of plan views, too. (Figure 21) Elevation drawings are occasionally used in details (Figure 22) as are, rarely, perspective views.(Figure 23) Multiple detail drawings are generally presented on one sheet, or may be added in available space on plan view sheets (see Figure 4, above). Often planting details are included on the planting plan drawing. (See Figure 3, above)

Figure 20. Sample cross-section details.

Figure 21. Sample plan view details.

Figure 22. Sample elevation detail.

Figure 23. Sample perspective detail.

Summary

Contract documents are a means for owners and designers to communicate with those who actually build, plant and create landscapes. Knowing where to find and how to read and interpret information in contract document sets is fundamental for the successful landscape industry professional.

For Additional Reading

•  Poage, W. 1991. The Building Professional’s Guide to Contract Documents, 3rd. ed.. R. S. Means, Kingston, MA.
• Collier, K. 2001. Construction Contracts, 3rd. ed. Prentice Hall, New York.
• Carpenter, P. & T. Walker. 1990. Plants in the Landscape. Waveland Press, Prospect Heights, IL.
• O’Brien, J. 1998. Construction Change Orders: Impact, Avoidance, and Documentation. McGraw-Hill Professional, New York.
• Harris, C. with N. Dines & K. Brown (eds.). 1997. Time-Saver Standards for Landscape Architecture, 2nd. Ed. McGraw-Hill Professional; New York.
• 2000. Landscape Specification Guidelines, 5th Ed. Landscape Contractors Association of MD, DC, VA