Site-erected frame, panel, module

The three methods

Frame erected on site

Production delivers cut-to-size, marked members, and the frame is assembled on site. Little space needed, simple transport, flexibility to site conditions.

In exchange, site work takes longer and quality depends more on the installers and the weather.

Panelised production

Wall panels — and often floor and roof elements — are assembled in the plant: frame, sometimes lining, insulation, sometimes even windows. On site the panels are put together.

Shorter site time, better controlled quality, in exchange for greater logistical demand and more constrained design.

Modular (volumetric)

Complete three-dimensional units are finished in the plant, often with linings, services and sometimes furniture. On site they are connected together.

The shortest site time and the highest factory quality, but serious transport and lifting requirements and the most constrained geometry.

What decides between them

• Site conditions: whether there is room for craneage, storage and access.
• Transport distance: moving large elements is expensive.
• Project size and repetition: prefabrication pays off better in series.
• Time pressure: where site time is critical, more prefabrication wins.
• Manufacturing capacity: whether there is an assembly plant or only profile production.

The legal consequence not to forget

In Hungarian regulation it matters whether the building is assembled from prefabricated panels or whether a frame erected on site is clad. The two are different legal categories requiring different verification.

This depends on the method of construction, not on the production line: the same machine can produce panels in a plant and cut members for site assembly. The concept of lightweight technology.

The effect on design

Panelisation is not a decision to take afterwards. If we think in panels, panel sizes, joints, lifting points and transportability have to be fixed during design. Panel size and transport.

The point

The degree of prefabrication is a strategic decision: it trades site time for logistics and design constraint — and on the way it can change the legal category as well.