A guide to prefabricated steel halls 2026: timescales, permits and price

What slows a hall down is not the building work but the paperwork. The erection of the steel structure with its envelope is itself measured in weeks, while the path from the first idea to the occupancy permit is measured in months — and mostly because every public-law body has its own deadline, and concrete has its own chemistry. This guide takes you through the whole path: nine phases with realistic timescales, when a permit is needed at all, what a hall really costs (and why two completely different prices per square metre circulate on the market) and what to check before you sign.

A note on 2026: since 1 January 2026 the new Building Act (NN 155/25) has been in force, replacing the previous one (NN 153/13, 20/17, 39/19, 125/19, 145/24). The same issue of the Narodne novine also carried the new Physical Planning Act and the new Act on Energy Efficiency in Buildings — all three in force from the same date. Guides older than that year no longer describe the procedure in force — check the date of every source you read, including this one.

Nine phases: where the time really goes

For a hall of the order of 1,000 m² the path from the enquiry to moving in realistically takes 8 to 15 months. What is decisive is to understand that these phases do not add up linearly: the production of the structure in the plant runs in parallel with the excavation and the concreting of the foundations, and it is precisely that parallel working that is the reason why a prefabricated hall beats conventional construction. What money cannot speed up are the deadlines of the public-law bodies and the 28 days — the standardised age at which the characteristic compressive strength of concrete is proved to HRN EN 206. (Concrete goes on gaining strength after that; 28 days is the measuring reference, not the moment at which concrete “becomes finished”.)

Permits: the short answer and the long version

The short answer: for a hall a building permit is practically always required.“A hall of up to 20 m²” does not exist as a category — what exists is a canopy of up to 20 m² outside the footprint of an existing building, an ancillary building with one storey of up to 50 m² on the plot of an existing building and for its needs, and an agricultural shelter for livestock, and all three come with strict conditions. Everything that is called a hall in practice requires a permit, and for the permit a design, the confirmations of the public-law bodies and a design check. The only difference the new act brings is the level of documentation: for a building of agricultural use of up to 600 m² of gross floor area— under the Building Act (NN 155/25, Art. 3 para. 1 point 32) a “less complex building” — the conceptual design is enclosed with the application instead of the main design (Art. 62). The main design is not abolished by that: it is still produced and must be on the building site (Art. 93).

Two things that clients regularly overlook. The first is the design check — for halls with a span of 10 m and more or a gross (construction) area of 800 m² and more the checking of the design is mandatory under the Ordinance on Design Checking (NN 32/14, 72/20, 90/23), Art. 3, and the checking engineer is a separate cost and separate time in the plan. The new Building Act provides for a new ordinance to be adopted, so check the threshold before you start designing. The second is fire protection: assembly halls — regardless of area — and workshops above 100 m² are classified as structures of group 2 (demanding structures) under the Ordinance on the classification of structures into groups by the demands of fire protection measures (NN 56/12, 61/12), Annex 2, point A2.5. That brings with it a fire protection study and possibly detection, extinguishing or smoke extraction systems — one of the largest single jumps in the price.

Why two prices per square metre circulate

This is the greatest source of disappointment in the whole process. When the structure supplier says “a hall costs about 100 € per square metre”, he is talking about the structure and the envelope— the frame, the roof and the walls. When the contractor says “building a hall is 300 € per square metre”, he is counting everything: the foundations, the floor slab, the services, the fire protection, the design and the permits. Both figures are honest, and the difference is of the order of two to four times, depending on the scope.

* The ranges are indicative and exclude VAT, as at August 2026. They are not a quotation — only a written quotation after a check of the dimensions, the use, the location and the scope of works is binding.

What raises the price, ordered by influence: the span (the moment in the frame grows with the square of the span — a double span is not twice as expensive but considerably more), the eaves height, the snow zone (under HRN EN 1991-1-3 and the national annex Slavonia lies in a band of the order of 0.5–1.0 kN/m², while the mountain regions are several times higher — and that means several times more steel for the same footprint), an overhead travelling crane, the fire requirements, the load capacity of the floor slab, the panel thickness, the number and size of openings, the quality of the ground and the services. More on how the span and the profile affect the consumption of steel in the guide to trapezoidal profiles.

The envelope: where it is decided whether the hall will be pleasant

The frame does the carrying, but the envelope determines how the work goes in the hall and what the heating costs. The key decisions and where we have set them out: a cold or a heated hall — trapezoidal sheet with anti-condensation fleece or sandwich panels (on fleece); the panel thickness by use and by the regulation (40 to 120 mm); the panel core and the fire class (PUR vs PIR); moisture and the sealing of the joints (vapour barrier and ventilation); and drainage (which gutter and how many downpipes).

Foundations and anchors: the millimetres that stop the crane

The most expensive standstill on the building site arises when the mobile crane turns up and the anchor bolts are not where they ought to be. HRN EN 1090-2, the standard for the execution of steel structures, therefore requires the inspection and handover of the supports before the erection begins, and the permissible deviations are measured in millimetres and depend on whether the anchors are cast rigidly into the concrete or prepared for adjustment — we have set out the difference and the specific figures in the article on columns and anchoring. A practical rule: before the crane sets off for the site, someone has to survey the anchors and sign that they are within tolerance. For the floor slab a second rule applies that is often broken — the load capacity of the subgrade is measured, not assumed, and the movement joints are cut according to the thickness of the slab, otherwise within a couple of weeks irregular cracks appear across the whole surface.

If this is too much at once, start at the end: tell us the use, the desired footprint and the location. The 3D view of a hall and the agricultural variant serve exactly that purpose — so that from the dimensions you get a first estimate before you enter the design stage. You will find the details of the structure itself on the page of the steel structures, and about finished buildings on the page of the prefabricated halls.

Two things that are most often overlooked at this stage: which type of girder suits your span and how much height it eats — a lattice or a solid-web girder— and the public charges that are in no contractor’s quotation: the utility contribution, the water contribution and the connection.

Send an enquiry with the dimensions and the use