Temporary works
Temporary works are things built only to help the job and removed afterwards. Examples: the site fence, the site office and store, scaffolding (a frame of poles and platforms for working at height), formwork (moulds that hold wet concrete until it hardens), temporary power and water, and cranes. They must be strong and safe, because workers stand on them.
Foundation and ground work
The foundation carries the building load to the soil. Soil is weaker than concrete, so the foundation spreads the load over a wide area: Area = load ÷ soil strength. Weak soil needs a wider footing or deep piles that reach strong layers or use friction along their sides.
Ground work covers digging (excavation), keeping the pit sides safe, pumping out water, filling and compacting soil, and laying a lean concrete layer under the footing.
Structural frame work
The structural frame (in Japanese practice also the main body work) is the skeleton that carries loads: columns, beams, floor slabs and structural walls. Common types are reinforced concrete (concrete with steel bars), steel frame, timber frame and masonry (brick or block walls). Steel bars are tied in place, formwork is built, concrete is poured and cured (kept damp) so it gains strength.
Finishing work
Finishing work makes the building usable, safe and neat: plaster, tiles, floors, ceilings, doors and windows, waterproofing and paint. It also controls heat and sound with insulation. Finishing hides services, so it comes after them.
Building services work
Building services are the systems that make a building work: water supply, drainage, electrical power and lighting, air-conditioning and ventilation, fire protection, lifts and communications. Pipes and ducts are usually fitted while the frame is built, and fixtures after finishing.
Seismic reinforcement work
An earthquake shakes the ground sideways, and buildings must resist this sideways force. Seismic reinforcement (retrofit) strengthens an old or weak building by adding steel braces, shear walls, wrapping columns with steel or carbon fibre, or adding base isolation (flexible bearings under the building). The aim is to reduce sway and prevent collapse.
Automation and labour-saving
Construction has heavy, risky and slow work and fewer young workers. Labour-saving methods help: prefabrication (parts made in a factory), cranes and power tools, concrete pumps, 3D digital models (BIM), drones for site photos and machines that lay bricks or tie steel bars. They cut time, mistakes and injuries.
Demolition and environmental conservation
Demolition is taking a building down safely. First hazards are removed (for example asbestos, an unsafe material found in old buildings), then the building is taken apart in a planned order. Waste is sorted: concrete is crushed for road base, steel is recycled, wood is reused, glass is recycled and hazardous waste is disposed of safely. Dust, noise and vibration are controlled to protect neighbours and the environment.
Try it
Foundation test: press a pencil on soft sand, then press a flat book on the same sand with the same push. The book sinks much less because the load is spread over a bigger area. Try it in the 3D too: slide the soil strength.
Key formulas and definitions
- Footing area = load ÷ soil strength
- Building layers: temporary → foundation → frame → services → finishing
- Seismic retrofit: braces / shear walls / wrapping / base isolation
- Demolition waste: sort → reuse / recycle → safe disposal
Worked examples
1. A wall carries a load of 300 kN on soil of strength 150 kN/m². What footing area is needed?
Area = 300 ÷ 150 = 2 m².
2. The soil is weaker, 100 kN/m². Same load. New area?
300 ÷ 100 = 3 m². Weaker soil needs a bigger footing.
3. Why are scaffolding and formwork called temporary works?
They are removed once the job is done. They only help build the permanent structure.
4. Why do pipes go in before plaster and paint?
Finishing covers the services. If the pipes were fitted after, walls would have to be broken again.
Common mistakes
- Thinking temporary works need no design. Scaffolds and formwork have collapsed, so they must be designed and checked.
- Making the footing the same size on weak and strong soil. Weak soil needs a wider footing.
- Painting before fitting pipes and wiring. Services go before finishing.
- Throwing all demolition waste in one pile. Sorting makes recycling possible and keeps hazardous waste safe.