Five Pillars of Architectural Vocabulary, Delivered Weekly on Sundays

Welcome back to The Five Orders! This week, we’re covering five architectural terms related to doors. We’ll explore the functional, symbolic, and spatial roles of these elements through our vocabulary for the week. The terms are: threshold, jamb, portal, transom, and lintel. If you don’t know one or more of these terms, keep reading to educate yourself further. Also, don’t forget to like, comment, and subscribe to De Architectura if you enjoyed!

The Five Orders

• Threshold: The threshold is the horizontal framing that forms the bottom of a doorway. They serve to seal the door, preventing water and other elements from getting through. They also serve to cover the gap between the floor and the door frame. Thresholds also provide a smooth transition from one side of the door to the other. Many cultures have attributed symbolic and spiritual importance to thresholds for this reason. They are commonly made out of materials like wood or aluminum for their resilience and inability to rust.

• Jamb: A jamb is the side post/lining of a doorway. It bears the weight of the door through the hinges. It ultimately ensures that the door opens and closes smoothly. Jambs are also used in windows and are called either reveals or jamb-shafts.

• Portal: A portal is an opening in a wall, normally found in grand entryways. It is common for portals in ecclesiastical architecture to feature a tympanum, a decorative semi-circular surface above the entrance. The purpose of the portal is to frame the entrance, bear heavy loads around the entrance, and to provide an architectural focal point to a building.

• Transom: A transom is a horizontal structural beam that separates a door from the window above it. It serves to provide natural light, ventilation, and aesthetic appeal to doorways. It also provides structural support alongside privacy as placing the window above the door makes it hard to directly see through.

• Lintel: A lintel is a horizontal structural support that is used to bear the weight of the wall above a door. They come in many different materials like stone, wood, concrete, brick, etc. They can be adorned with carvings to serve a more ornamental effect, but they are most commonly used just for structural support.

If you learned something, make sure to like, comment, and subscribe to De Architectura below!

Sources:

“Door Terms: What Is a Transom?” Euroline Steel Windows & Doors, https://www.eurolinesteelwindows.com/door-terms-what-is-a-transom/. Accessed 4 May 2025.

“Jamb Definition in Construction: A Complete Guide.” Al Syed Construction, https://alsyedconstruction.com/jamb-definition-in-construction-a-complete-guide/. Accessed 4 May 2025.

“What Is Lintel and Its Types?” UltraTech Cement, https://www.ultratechcement.com/for-homebuilders/home-building-explained-single/descriptive-articles/what-is-lintel-and-its-types. Accessed 4 May 2025.

“Portal (Architecture).” Britannica, https://www.britannica.com/technology/portal-architecture. Accessed 4 May 2025.

“Threshold: Link and Separator.” Architecture Design Primer, 8 Jan. 2013, https://architecturedesignprimer.wordpress.com/2013/01/08/threshold-link-and-separator/. Accessed 4 May 2025.