Using the Orders

The five standard orders and their dimensions were introduced previously here. Guidelines to follow when using the orders are found below.

2a. Stick to the five orders; avoid creating your own.

There is enough variety between the five that at least one will meet your needs. Be aware that the orders are not appropriate in every situation. Some settings where they are not appropriate are:

• Cottages, cabins, and chalets: may use plain, turned, or carved posts
• Victorian buildings (and other similar styles): may use turned or carved posts
• Romanesque buildings
• Gothic buildings

There are a number of variations on the orders such as Erechtheum Ionic, Tower of the Winds, Zoomorphic, Castor and Pollux, and even Caryatids. However, unless you are an experienced traditional architect sure of your intent, it’s best to stick with the standard orders.

2b. Triglyphs and modillions shall be centered over columns.

When employing the Doric order, every column shall have a triglyph centered over it. The space between two triglyphs is called a metope. Triglyphs should be spaced in such a way as to make the metopes close to square in shape. Metopes can contain decorative elements or be left plain.

When employing the Corinthian or Composite orders, every column shall have a modillion centered over it. This is a firm guideline and must occur regardless of the intercolumniation. For more information on intercolumniation, see Guideline 2k below.

Dentils can also be centered over columns. However, this is not required as dentils do not emulate a structural component.

2c. Horizontally, there should be an even number of columns.

An even number of columns ensures there is an opening in the center. For more information see Guideline 4e. Horizontally, there should be an odd number of openings.

2d. Round columns shall have entasis (tapering), square columns should not.

Entasis is a gradual tapering that begins one third from the bottom of the shaft, and ends at the top of the shaft. For how much columns should taper, please see Michael Rouchell’s drawing on the Orders and Their Dimensions.

It is a debatable whether square columns (also called piers) should have entasis. There are many examples, particularly throughout the UK and the US, where they do. However, Renaissance masters in Italy did not employ entasis on their square columns. Entasis on round columns makes them appear organic and alive. However, for piers, straight square edges appear more structurally sound than square edges with entasis. This is especially applicable on the corners of buildings.

In all other aspects square columns should share the same dimensions as their round counterparts. The width of square columns should match the diameter of the round columns at their base. This means the bottom of the capital will be wider on square columns than on round columns. However, by the top of the capital, both should even out to be the same width. It is very important to match the diameter at the bottom of the round column. If the width of the square column matches the diameter of the round column at its top, the square column will appear spindly and weak. Especially if placed beside a round column.

St. Peter’s east façade below, employs both round and square columns. Notice how the square columns do not have entasis and are the same width as the diameter at the bottom of the round columns.

2e. The frieze (the middle component of the entablature) shall align with the top of the column’s shaft.

This shall occur not only on the ends, as illustrated by Michael Rouchell’s drawing on the Orders and Their Dimensions, but also on the face of the frieze. An entablature and frieze cantilevering out beyond the columns shall not occur.

2f. The projecting portion of engaged columns.

Engaged columns are columns that are attached to a wall. It would seem logical that for both round and square columns, half of the column should project from the wall. However, this is not the case. For round columns, around 3/4 should project from the wall. Interestingly enough, for engaged square columns (also called pilasters) it is the opposite; around 1/4 should project from the wall.

Below, the engaged columns around the drum of Saint-Augustin’s dome illustrate this concept.

2g. Columns shall have a base, a capital, and an entablature.

Pedestals and balustrades/parapets are optional. Early Greek Doric columns lacked a base. However, this was corrected in the later Ionic and Corinthian orders and in the Roman Doric variant.

The only exception to this rule is arcades. Columns in an arcade may have an entablature; however, most often they do not. The arcade on Plaza de la Catedral in Havana, Cuba is an example of one that does not.

2h. Column abaci and plinths shall be square.

The topmost part of the column’s capital is called an abacus. The bottommost part of the column’s base is called a plinth. Both abaci and plinths shall be a square form. This is applicable for both square and round columns.

For Tuscan and Doric orders, and Ionic orders with parallel volutes, abaci are a plain square shape. For Scamozzi Ionic, Corinthian, and Composite orders, the square’s sides are concaved and their corners trimmed, producing an undulating square form.

For all orders, plinths are a plain square shape. When the column is placed atop a formalized pedestal, the plinth edges shall align with the center section of the pedestal. Sometimes it is wished to raise a column, but not enough that a formal pedestal is required. In these cases, surmounting the column on a plain block is acceptable. The block which the column stands upon shall be slightly wider than the plinth. This allows the plinth to be clearly seen as a distinct component, separate from the block.

2i. The correct progression of superimposed orders.

Please see Guideline 6d. For superimposed columns, wider orders go below narrower orders.

2j. The correct width of superimposed orders.

When superimposing columns, it is important to ensure the facade does not appear top heavy. Accordingly, the generally accepted guideline is: The diameter of the upper order should be 7/8 the diameter of the lower order. When round columns are used, and hence entasis, this results in the upper order’s diameter at the bottom of the column equaling the lower order’s diameter at the neck of the column.

However, when orders are skipped, for example the Corinthian order superimposed directly upon the Tuscan order, the 7/8 guideline can result in the upper order being taller than the lower order. In these cases the height of the upper order should be limited to that of the lower order. This will result in the upper order’s diameter being less than 7/8 the lower order’s diameter which is acceptable in these cases.

2k. Fluting

Flutes are the vertical grooves found on some columns. With the exception of the Tuscan order, fluting is optional. Tuscan columns shall not have flutes. If Doric columns have flutes, they should have 20. If Ionic, Corinthian, or Composite columns have flutes, they should have 24.

Flutes are constrained to the shaft and should never run into the base or capital. Normally flutes extend from just above the base to just below the capital. However, sometime entasis is complimented by placing an additional bead within the flute in the bottom third of the column (called cabled fluting), or by simply starting the fluting one third from the bottom of the shaft, and ending it just below the capital. Recall from Guideline 2d above, that entasis starts one third from the bottom of the shaft.

The Madrid Stock Exchange below, exhibits the Composite order with cabled fluting.

2l. Giant Order Columns

Giant, or colossal, order columns were introduced in the Renaissance and span two or more stories.

As a general rule of thumb, at least twice the number of columns should be used as the stories being spanned. For example, when spanning two stories, use at least four columns. When spanning three stories, use at least six columns. This a soft guideline only and may be circumvented. Depending on the column spacing and the overall height of the windows it may be acceptable to have two columns spanning two stories, or four columns spanning three stories. However, following this guideline will ensure the façade does not appear too spindly or weak.

The Royal Institute of Great Britain is a good example of the giant order. Here, fourteen columns span three stories. Place your hands over either side of building so only the center six columns are visible. With six columns spanning three stories the façade still looks beautiful and stately. However, try covering all but the center four columns. Now the façade begins to look excessively vertical and spindly.

2m. Intercolumniation

Intercolumniation is a term that refers to the spacing of columns. Normally columns are evenly spaced with a distance of one and a half to four times the column diameter between them. However, there are two common cases where columns are not evenly spaced.

Araeosystyle intercolumniation. This is simply coupled columns. All columns may be coupled or just the outer pair. Essex County Courthouse below employs coupled columns, or araeosystyle intercolumniation.

Eustyle intercolumniation. In this case the center columns have a larger space between them than the other columns. This larger space can be quite subtle in the Tuscan, Ionic, Corinthian, and Composite orders. A space of three diameters between the center columns and two and a quarter diameters between the other columns is common. However, triglyphs must be taken into account when employing eustyle intercolumniation with the Doric order. Recall from Guideline 2b above that triglyphs shall be centered over columns. Triglyphs shall also be evenly spaced. This means the only way to employ eustyle intercolumniation with the Doric order is to have more triglyphs between the center columns than the other columns.

This is illustrated below by Vilnius Cathedral in Lithuania. Notice how there are two triglyphs between the center columns, but only one triglyph between the other columns.

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