What is architectural form?
A building has a form: its shape in space. We build a form from simple volumes such as cubes, long boxes, cylinders and domes.
When we place volumes together we make a composition. A good composition has a main volume and smaller helpers, so the eye knows where to look. Making small paper or cardboard models of volumes is the best way to test ideas.
Tectonics: how a building stands up
Tectonics means the art of putting parts together so they hold up and also look good. Every structure moves weight to the ground. We meet three main ideas:
- Post and lintel: vertical posts carry a horizontal beam (the lintel). Simple, but the beam can only be as long as the material allows.
- Arch: wedge-shaped stones lean on each other. The middle stone is the keystone. An arch can cover a wider gap than a stone beam.
- Dome and shell: a curved surface that spreads weight round the edge. It covers a big room with no inner posts.
Building materials and structures
The material decides the structure.
- Stone: heavy and strong when pressed, weak when pulled. Good for arches and thick walls.
- Brick: small, easy to carry, good for walls, arches and domes.
- Wood: light, takes some push and some pull. Good for beams and roofs.
- Steel: strong both ways, so long, thin beams and tall frames are possible.
- Glass: lets light in, but it is a filling, not a frame.
A new material often brings a new form: steel and glass made tall towers possible.
Try it: build a form at home
Take 10 small blocks, cards or books. 1) Build two stacks with one flat card on top (post and lintel). How long a card can you use before it bends? 2) Try to curve cut-out cards into an arch over a gap. 3) Roll a sheet of paper into a tube and stand it up: see how a curve is strong. Write one line about what you saw.
Key formulas and definitions
- Form = volumes + composition
- Tectonics = how parts carry weight to the ground
- Post and lintel: posts carry a beam
- Arch and dome: curves spread the push
- Material decides the structure
Worked examples
1. A hall needs a roof over a 12 m gap. Wooden beams are only 5 m long. Which structure can help?
An arch, a dome or a steel truss. They carry the roof over the gap in one go, while 5 m wooden beams on posts would need posts inside the hall.
2. Name the three volumes in a school made of a tall tower, a long classroom block and a round hall.
Tall box (tower), long box (classroom block), cylinder with a dome (hall). Together they make a composition.
3. Why is stone good for an arch but not for a long thin beam?
Stone is strong when pressed but weak when pulled. In an arch every stone is pressed. In a long beam the lower side is pulled and the stone cracks.
4. You want a big, bright glass front for a shop. Which material should carry the load?
Steel or concrete. Glass only fills the opening; a steel frame carries the weight.
Common mistakes
- Thinking form means only the outside look. It also includes how the building stands.
- Mixing up the arch and the lintel. A lintel is straight; an arch is curved.
- Saying glass can hold a building up. Glass is a filling.
- Forgetting that the material decides what structure is possible.