Hall construction methods compared: steel, concrete and timber

Before comparing methods, some perspective is worth having. It shows how much of the decision actually rides on the choice.

Item	Share of a hall's construction cost
The structure	25 to 35 %
Floor slab, envelope, insulation, doors, services, fit-out	65 to 75 %

That considerably relativises the construction method debate, and the arithmetic fits on one line. It shows why insulation, the floor slab and the fire strategy act more strongly than the choice of frame.

Quantity	Value
Price difference between two structural options	10 %
Share of the structure in the budget	around 30 %
Effect on the total investment	around 3 %

The method is nevertheless not incidental, but for a different reason: it determines which spans, hall heights and fire solutions are economically reachable at all, and it acts on programme and on later adaptability. It therefore governs usability rather than the price per square metre.

The properties can be set side by side before each is described. None of the three is superior on every row, and the dependence on the project situation follows from exactly that.

Property	Steel	Precast concrete	Timber
Share of German hall construction	largest	common	niche, often as a hybrid
Long spans	good	limited	most economical
Fire behaviour	loses load capacity quickly when heated	favourable	combustible, loses section slowly
Weight and foundations	light, smaller foundations	heavy, larger foundations	light
Adaptability and extension	high, predominantly bolted	low, openings costly	medium
Erection time	short	usually longer	short
Protection required	galvanising or coating	none	chemical protection, lamination

Steel. The most widespread method in German hall construction. Slender sections leave more usable hall area, pinned column bases permit smaller foundations, and predominantly bolted connections make alteration, extension and in the extreme case even dismantling and re-erection elsewhere possible. Corrosion protection is by hot-dip galvanising or coating. The weakness lies in fire behaviour: steel loses load-bearing capacity rapidly on heating, so fire resistance requirements force additional protection.

Precast concrete. More robust and durable, with clear advantages under high loads, mechanical wear and fire requirements. The drawback is weight, demanding larger foundations and heavier erection plant, together with a generally longer programme. Precast is also less adaptable, since subsequent openings and alterations are demanding.

Timber. Economic above all at large spans, because the ratio of capacity to self-weight is favourable. On fire the assessment is counterintuitive: timber is combustible, but loses section and therefore capacity only slowly in a fire, so a timber hall remains stable for a long time and burns in a controlled way. Chemical protection against pests and fungal attack must be allowed for, as must the lamination of load-bearing sections. Hybrid forms are frequently encountered, with only the roof structure in timber.

Situation	Usually economic
Hall up to about 1,500 m², standard requirements	steel
Hall from about 1,500 m² with high loads or demanding fire requirements	precast concrete
Hall from about 1,500 m² with large spans	timber
Hall with crane runway and heavy loads	steel or concrete, depending on fire resistance required
Hall with a later extension intended	steel
Hall with an aggressive internal atmosphere	concrete or protected steel, depending on the medium

These thresholds are orientations, not limits. They shift with the market in steel, concrete and timber, whose prices have each moved on their own path in recent years, and with hall geometry.

In practice the construction method is decided less often on price than through the fire strategy. The required fire resistance period follows from hall size, compartmentation, use and stored goods, and from the applicable state law and industrial building guideline.

The relationship works both ways. A higher fire resistance requirement raises the cost of a steel structure disproportionately, because additional protection becomes necessary, and shifts viability towards concrete or timber. Conversely, a sprinkler installation can reduce the requirement on the structure and bring a cheaper method back within reach.

A sequence for cost estimating follows: fire strategy first, then construction method, then price comparison. Working in the reverse order compares options one of which will later prove unconsentable.

Steel structures in Germany fall under a binding normative framework with execution classes graded by loading and by the consequences of failure. Higher execution classes bring stricter requirements for weld inspection, verification and documentation, and act directly on price.

Professional sources note that particularly cheap offers from abroad do not always meet these requirements. A price comparison between a compliant and a non-compliant offer is not a price comparison but a comparison of two different products, one of which is unusable.

Check rule: before any comparison of offers, the execution class must be established and reconciled with the project's requirements. It belongs in the tender documents, not in the negotiation.

One aspect missing from conventional cost comparisons is gaining weight in commercial development: what happens to the hall at the end of its use. Dismantling and recyclability differ considerably between the methods.

Commercial buildings are dismantled or converted more often than housing, because they are tied to a business rather than to a location. The methods differ markedly here.

Method	At the end of its use
Steel	dismantled and re-erected elsewhere, indefinitely recyclable
Precast concrete	hard to separate, generally crushed and recovered as aggregate
Timber	renewable, reusability depending on lamination and chemical treatment

This acts on cost estimating in two ways. First through residual value at the end of use, which can be positive rather than negative for demountable structures. Second through sustainability requirements from investors and funding programmes, which increasingly demand evidence of circularity and thereby feed back into the choice of method.

Three points are frequently attributed to the construction method although they are fixed independently of it. They follow from the use and from building law.

What is attributed to the method	What it actually depends on
Insulation quality	the envelope build-up, usually sandwich panels; achievable to the same standard with all three frame types
The floor slab	the use; unrelated to the choice of frame
Construction time as a whole	earthworks, foundations, floor slab, envelope and fit-out; frame erection is only one section

For early cost estimating this means the choice of construction method is one decision among several, and not the most effective one. The items with the greatest leverage in hall construction are insulation, floor slab, hall height and fire safety.