Flattened ellipse arch
 

Segmental arch
 

Roman arch, with header and beam height
 

Few-to-No imperatives

	The house doesn’t have to be large or of
	Any particular architectural style, usually

Choices (a sampling)

	By structure Intersecting arch – crossing each other as in an arcade, presenting both rounded and pointed arches in the making Blind arch – solidly filled in below to the base of column, pier, abutment, pilaster or wall Relieving arch – structural element Arcade arch – columns in series, supporting arches Colonnade arch – not really an arching at all, rather columns in series supporting, effectively, a beam called “architrave" Bowstring arch
	By shape Roman arch or semi-circle arch Flat arch or jack arch or splayed arch Gothic arch or pointed arch, of which acute arch or lancet arch may be a subset Tudor arch or depressed or flattened Gothic arch Syrian arch or segmental arch Moorish arch or horseshoe arch
	By accessory Spandrel Soffit Impost – this home designer prefers these arch design features, trimmed variously and consistently Hood moulding (a/k/a hood mould, hood mold, hood molding, collar molding)– also applied over-door and over window interior and exterior Voissoirs Cusp Tympanum Lintel Keystone
	By support Column Pier Abutment Pilaster Wall, usually with impost
	By physical relationship Bowstring Springing or springline Springer Haunch Crown Intrados – interior curve of arch Extrados – exterior curve of arch
	By geometry Major axis or span Minor axis or rise from the springline Arch base vertical alignment with top, interior edge of column, pier, or abutment

The Orders in so far as embellishments are concerned

	Greek Doric Ionic Corinthian
	Roman Tuscan Composite
	Nonce British American

It mimics the exterior arches in segmental form and shallow minor axis, but also because
 

These interior portals are not close together physically. Finally,
 

In the style of design of the instant project,

	Header height had no stylistic basis for variation and, indeed,
	The regularity of interior door header height benefited desirable openness in-between larger spaces.

Of interest, these sections were not the first drawn, which first drawn were more rounded [read: marginally longer minor axis] and regarded by the clients as in need of flattening, which flattening extended to all arches both interior and exterior, considering that the exterior Front Of House arch across the wide Front Porch formed the basis for all other arch proportions.
 

It is the experience of Before The Architect’s designers that when arches get closer together, as in a series, as in a colonnade, it’s more salutary design to hold to the math of major:minor axes across the series.
 

Before The Architect is fond of a segmental arch at major axis:minor axis::9:1, when window heads are segmental, which is almost all the time [as opposed to the semi-circular, or Roman arch, of which clients are less fond, leaving elliptical somewhere in the middle by popular demand hereabouts].
 

If sequenced, as in a porch or arcade, segmental arches appear most regular when each is set at a given major-to-minor axis ratio, say 9:1, and all the springlines are held to a singular level, thereby offering marginally different crown heights when intercolumn distances vary.
 

The Interior Arches In Series pic presents the stripped-down version of layouts recently done to be sure about the preferential appearance of arches in series.
 

The context is

	An 8'x38' Gallery interior facing a 20'x38' Dining and Living area.
	Front entrance is on-center.
	The wider middle wall opening is set to permit full view out the far-side window wall immediately upon entrance.
	The flanking openings are equal in width and the piers and abutments are equal in width.
	Note that header height is less important in this instance as the 38' length will be taken up with beams above Gallery ceiling level, the Gallery height being 10' and the Dining-Living area being twice that.

The tight series of openings requires more discipline in laying out the arches. While some disproportion from the Gallery view could be tolerated, the substantially wider visual perspective from the Dining-Living area would put the lie to bad judgment.

	#1 conforms both springline and minor axis based on the center arch.
	#2 conforms springlines, but holds major:minor axes proportions hard to the center arch, thereby slightly lowering the flankers heights.
	#3 conforms proportions as in #2, but levels the arches' apices, thereby lifting the flankers' springlines over the center's.

#1 and #3 fail for the same reasons - disproportion, particularly from the Dining/Living viewpoint, and understatement of the central, arched opening.
 

Arch's overall consequences can be

	Favorable: incremental formality
	Favorable: the pleasant perspective of design latitude in lieu of dogma
	Favorable: unobligated opportunity for accessories and
	Favorable: pleasing proportion and regularity (unless you’re clueless about proportion and regularity, in which case find someone who is not clueless to help you)

Discrete treatment of the front door arch in order to distinguish it from all other arches
 

Identical treatment of similar, lesser passage at Front Of House and Back Of House
 

Cross-reference to the Elevations as further guide to application
 

The attention even to the arching of Courtyard wall doors
 

Same springline and minor axis to the Front Porch LOH and ROH as the Front Porch FOH, even though the two sets of arches have widely dissimilar major axes, in order to provide a symmetrical frame of visual reference both from and toward the house, particularly from the house Front Porch
 

Note also, please the references to the interior doors drawn in the above Figure.