OBRALIAAlready built to height
Buildings of 2, 3, 4 and 5 storeys printed and in use in Germany, Switzerland, China, the US, Belgium and Africa since 2015.
The evidence behind 3D concrete printing for multi-storey buildings
Documents, completed buildings and calculations that answer a single question: is 3D concrete printing ready for a multi-storey building? Yes, and it has already been done.
Technology dossier for architects and investors. Data from public sources consulted in September 2026 and from tests by the printing system manufacturer. The structural verification and programme figures are an example from a reference project, not a guarantee for another building: each project is calculated with a signed and professionally endorsed (visado) execution design.
Six reasons to have no doubts
International standards in force
ISO/ASTM 52939:2023, ICC-ES AC509 criteria (multi-storey revision) and UL 3401 already regulate printed construction.
Thoroughly proven material
90 MPa structural 3DCP mortar: 3.0–3.6 times the strength of conventional C25/30–C30/37 concrete.
Huge safety margins
In the reference building, the printed wall works at 6.7% of its capacity: safety factor ≈ 15 on loads that are already factored.
Backed by industry giants
Holcim, GE, CEMEX and PERI are shareholders of COBOD; ICON has raised more than $450 M. Decades of R&D before reaching the market.
With a roadmap in Spain
Performance-based CTE (Código Técnico de la Edificación, Spanish Building Code) + Código Estructural (Spanish Structural Code) + DIT assessment (Documento de Idoneidad Técnica, technical suitability document, issued by IETcc): the same path already followed in Germany and the US.
From the digital model to the finished wall
BIM model
The whole building is modelled digitally: geometry, walls, services and textures.
Print code
The model is translated into layer-by-layer toolpaths. Every bead is defined to the millimetre.
Batched mix
The automatic plant batches the mortar with continuous consistency control.
Layer-by-layer printing
The gantry deposits beads of 30–150 mm; reinforcement rings and starter bars are integrated during printing.
Recording and control
Every layer is recorded: time, speed, flow and temperature. Full traceability of the works.
Dual-head gantry printer (COSMOS Y15 DUAL system)
- Maximum speed
- 300 mm/s
- Heads
- 2
- Double wall / 8 h shift
- 72 m²
Almost 30 years of R&D before reaching the market
- “Contour Crafting” is born at the University of Southern California: first patents for printing buildings.
- WinSun (China) prints 10 houses in a day and the world's first 5-storey apartment block.
- COBOD (Denmark) prints the first building in Europe and launches the BOD series.
- The German group PERI (formwork, 1969) acquires a stake in COBOD.
- The Holcim–COBOD collaboration begins; Dubai opens the largest printed building (640 m²).
- Kamp C (Belgium) prints 2 storeys in one piece; Wallenhausen (Germany): first multi-family building approved and let; the world's first printed school (Malawi, Holcim).
- GE, CEMEX and Holcim become COBOD shareholders; ICON surpasses $450 M raised.
- The international standard ISO/ASTM 52939 is published; Kenya: 52 homes with Holcim's TectorPrint ink.
- Wave House (Heidelberg): largest printed building in Europe; Wolf Ranch (Texas): 100 ICON–Lennar homes.
- Tor Alva (Switzerland, ETH): 30 m, 4-storey load-bearing tower, world height record.
- OBRALIA 3D applies this mature value chain to a 4-storey apart-hotel with a basement.
The world already builds printed, and to height
Eight documented milestones on four continents. These are not laboratory prototypes: they are buildings approved by their authorities, sold, let and lived in.
| Project | Year | Scale | Milestone |
|---|---|---|---|
| Wave House · Heidelberg (DE) | 2024 | 600 m² · 54 m long | Largest printed building in Europe · data centre in operation |
| Wallenhausen (DE) | 2020 | 3 storeys · 5 homes · 380 m² | First printed multi-family building: approved, completed and 100% let |
| Tor Alva · Mulegns (CH) | 2025 | 30 m · 4 storeys | Tallest printed load-bearing structure in the world (ETH Zürich) |
| Wolf Ranch · Texas (US) | 2024 | 100 homes | Largest printed community in the world (ICON + Lennar), on sale at $450–600k |
| Mvule Gardens · Kilifi (KE) | 2023 | 52 homes | Largest printed affordable housing development · Holcim TectorPrint ink |
| Kamp C · Antwerp (BE) | 2020 | 2 storeys · 8 m · 90 m² | First 2-storey house printed on site in a single piece |
| Municipal offices · Dubai (UAE) | 2019 | 640 m² · 9.5 m | Largest printed building in the world at the time · Guinness record |
| 5-storey block · Suzhou (CN) | 2015 | 5 storeys · 1,100 m² | First 5-storey building with printed elements (WinSun) |
Wave House: the largest in Europe
- Floor area
- 600 m²
- Dimensions
- 54 × 11 × 9 m
- Total printing time
- 140 h
- A critical industrial buildingNot a pilot home: an operational data centre, with extreme security and climate requirements.
- Undulating walls impossible to formThe geometry that gives the building its name is only feasible by printing.
- 4 m² of wall per hourPrinted by a COBOD BOD2 gantry, the same type of gantry machine used by OBRALIA 3D.
- Private developer, market logicKRAUS GRUPPE chose it because “3D printing made the project economically viable”.
Source: COBOD International (cobod.com). Opened February 2024.
Wallenhausen: 3 storeys, approved and let
- Storeys
- 3
- Homes
- 5
- Floor area
- 380 m²
- Completed
- 2020
- World's first printed multi-family building5 homes and 380 m² in Bavaria, printed on site by PERI with a COBOD BOD2 (2020).
- 72 hours of pure printingThe complete wall structure, in six weeks of total site time.
- Fully approved by the German authorityGermany demands some of the strictest approvals in Europe, and the building obtained them.
- 100% let within a year of completionFive families have lived in it since 2021: the definitive proof of habitability is that it is inhabited.
Source: PERI 3D Construction (peri3dconstruction.com). Material: Heidelberg Materials.
Tor Alva: 30 metres of load-bearing concrete
- The tallest printed structure in the world4 storeys and 32 printed columns of white concrete, inaugurated by ETH Zürich in May 2025.
- Reinforcement integrated during printingOne robot deposits the concrete; another places a reinforcement ring every 20 cm, plus longitudinal bars: “reinforcement that grows”.
- Printed load-bearing elementsFirst structure whose printed columns carry the building: the leap to multi-storey construction.
- Top-level scienceDeveloped by the ETH Zürich chairs in digital fabrication, materials chemistry and structures.
Press: Dezeen, 21 May 2025, “World's tallest 3D-printed tower unveiled in Switzerland”.
From pilot house to whole neighbourhood
- Wolf Ranch: 100 homesThe largest printed community in the world: ICON prints, Lennar (one of the largest US developers) sells at $450–600k.
- Kamp C: 2 storeys in one piece8 m high and 90 m² printed on site without joints (Belgium, 2020): a gantry prints upper floors without being dismantled.
- Dubai: Guinness recordMunicipal offices of 640 m² and 9.5 m high (2019). Dubai requires 25% of its new construction to be printed by 2030.
Material: three times stronger than the concrete of a conventional building
Characteristic compressive strength at 28 days. The structural printing mortar performs in the category of very high-strength concretes.
90 MPa is equivalent to 918 kg on every cm².
The world leader in concrete is already printing at scale
- COBOD shareholder since 2022Holcim is not merely watching the technology: it owns part of it. It has collaborated with COBOD since 2019 and took a stake in 2022.
- TectorPrint: its own structural inkPrinting mortar developed by its global R&D, with up to 50% less material for the same performance.
- 52 homes in Kenya and the world's first printed schoolIts subsidiary 14Trees (with British International Investment) delivers real housing certified EDGE Advanced by the IFC (World Bank).
- Striatus (Venice 2021) and Phoenix (2023) bridgesWith ETH Zürich and Zaha Hadid Architects: circular, reusable printed structures.
- Homes in the project
- 52
- Material with TectorPrint
- −50%
- IFC certification
- EDGE
No longer a legal vacuum: there is a standard, a criterion and a precedent
International framework in force
- ISO/ASTM 52939:2023International qualification standard for additive construction (structural elements). Published and adopted as an EN in Europe.
- ICC-ES AC509 (2021, rev. 2023)Acceptance criteria for printed concrete walls in the US, extended to multi-storey buildings. Basis of the 100 homes in Texas.
- UL 3401Safety evaluation scheme for 3D-printed buildings.
- Case-by-case European approvalsGermany (Wallenhausen, Beckum, Wave House), Belgium (Kamp C) and the Netherlands (Eindhoven) have already authorised and accepted printed buildings.
The roadmap in Spain
- Performance-based CTEThe Código Técnico (Spanish Building Code) admits non-traditional solutions by demonstrating performance, the route used by every construction innovation in Spain.
- Código Estructural + EurocodesSlabs, foundations and reinforced elements are calculated and built to conventional standards in force (Código Estructural, Spanish Structural Code): nothing experimental.
- DIT / DAU (IETcc–CSIC)The Documento de Idoneidad Técnica (DIT, technical suitability document, assessed by IETcc–CSIC) evaluates innovative systems: the formal route for the printed wall, with accredited laboratory tests.
- External control (OCT) and seguro decenalThe project undergoes the same technical control (OCT, Organismo de Control Técnico) and insurance (seguro decenal, ten-year structural liability insurance) as any Spanish development.
Verifiable certificates (from the material's issuers and suppliers)
Register of the official certificates covering the material, the construction system and the precedents cited. They are certificates held by their owners (for example, the concrete supplier), public and downloadable from the issuers' websites. On each project, these are supplemented by per-day specimen tests in an ENAC-accredited laboratory, external technical control (OCT), seguro decenal (ten-year liability insurance) and DIT assessment.
| Issuer | Certificate | Holder / scope | Verification |
|---|---|---|---|
| AENOR · IQNet | ISO 9001:2015 · ER-0550/2000 | Holcim España, S.A.U. · quality management: production and supply of concrete, mortar and aggregates | holcim.es/certificaciones-hormigon |
| AENOR · IQNet | ISO 14001:2015 · GA-2020/0243 | Holcim España, S.A.U. · environmental management | holcim.es/certificaciones-hormigon |
| CE marking + RD 163/2019 | EN 206 · production control | Holcim España concrete plants · certificate per plant, in force | holcim.es/certificaciones-hormigon |
| ICC-ES | AC509 · ESR-4623 (05-10-2022) | 3D printing system + structural ink (Black Buffalo 3D / MAPEI) · world's first evaluation report for 3D-printed walls | icc-es.org |
| ISO / ASTM | ISO/ASTM 52939:2023 | Additive construction: qualification principles | iso.org/standard/81177.html |
| IFC · World Bank | EDGE Advanced · 2023 | Mvule Gardens, 52 homes (14Trees: Holcim + British International Investment) | 14trees.com |
Official manufacturer tests · Cosmos Proof programme
The real wall, taken to failure in the laboratory
COSMOS 3D (Katz / IT3D group), manufacturer of the printing system, tested to failure a double-leaf printed wall in accordance with ABNT NBR 16868:2020 at the LAEES-UFMG structures laboratory (Federal University of Minas Gerais): eccentric compression (e = 2 cm) and out-of-plane bending.
- Failure load · eccentric compression
- 964 kN
- Per metre of wall
- 618 kN/m
- Failure moment · bending
- 1.92 kN·m/m
- Maximum deflection
- 2.83 mm
964 kN is ≈ 98 tonnes (the weight of 65 cars) on a wall with 50 mm leaves. The reference building's wall uses 70 mm leaves (40% more section) and carries a design load of 239 kN/m: the measured failure load is already 2.6 times that demand.
Acoustics, water and durability, also with test reports
- Sound insulation: Rw = 64 dBDouble printed leaf (2 × 50 mm + 100 mm cavity), per NBR ISO 12354-1:2023: +16 dB over the limit between dwellings and +25 dB over class III façade. “Superior” level under NBR 15575, the highest acoustic class.
- Water tightness: 0.00 m² of wet areaFaçade panel (including the joint between panels) sprayed under pressure at 3.0 L/min/m² at 50 Pa for 7 hours continuously: interior face completely dry (NBR 15575, LAEES-UFMG).
- Thermal shock: 10 of 10 cycles without damageSpraying was carried out after 10 cycles of heat at 80 °C with cold-water shock (NBR 15575:2024): no cracking or spalling.
- The same typology as the reference buildingThe configuration tested (double printed leaf with cavity) is that of the building, with even larger leaves (70 mm) and 30 cm in total.
Manufacturer reports available on request.
Acoustics, water, strength and energy: the full picture
Reference building: 4-storey apart-hotel with a basement in climate zone B4 (Seville). Each performance requirement comes with its project calculation, the manufacturer's test and on-site verification by an ENAC-accredited laboratory, under external technical control (OCT), seguro decenal (ten-year liability insurance) and DIT assessment by IETcc–CSIC.
Rw = 64 dB tested · 55–58 dB estimated in the building
Mass law: 322 kg/m² → Rw ≈ 52 dB + ≈6 dB for a double leaf with cavity. Manufacturer's report (NBR ISO 12354-1:2023): Rw = 64 dB, +16 dB over the limit between dwellings, Superior level.
CTE DB-HR: ≥ 50 dBA between units → ample margin
On-site verification: ISO 16283-1/-2/-3 in situ · final acoustic report
0.00 m² of dampness tested · penetration ≤ 30 mm
COSMOS test (NBR 15575, LAEES-UFMG): pressure spraying at 3.0 L/min/m² at 50 Pa for 7 h continuously, after 10 thermal cycles at 80 °C: 0.00 m² of wet area on the interior face, joint included. High-density 90 MPa mortar (EN 12390-8: max. ≤ 50 mm, mean ≤ 30 mm) and a double barrier: outer leaf + drained cavity + inner leaf.
CTE DB-HS 1: impermeability grade required in Seville → met
On-site verification: EN 12390-8 · absorption EN 13057 · in-situ façade spray test
964 kN tested failure load · FS ≈ 15 in design
COSMOS failure test (ABNT NBR 16868:2020, LAEES-UFMG): 964 kN = 618 kN/m with 50 mm leaves, 2.6 × the building's demand (239 kN/m), which in addition uses 70 mm leaves. Design verification: N_Rd = 3,570 kN/m → utilisation 6.7%.
Código Estructural (Spanish Structural Code) / Eurocode 2 → exceptional margin
On-site verification: EN 12390-3/-5 per working day · interlayer bond · EN 12504-1 cores
U ≈ 0.26 W/m²K · 2.2 × better than the CTE
R = 0.17 + 0.085 (140 mm concrete) + 3.43 (120 mm insulation) + 0.18 (cavity) = 3.86 m²K/W → U = 0.26 W/m²K. The 322 kg/m² mass adds thermal inertia that dampens heat and reduces the air-conditioning demand.
CTE DB-HE zone B4 (Seville): U_lim = 0.56 W/m²K → margin × 2.2
On-site verification: Blower Door ISO 9972 · thermography EN 13187 · target energy certificate (CEE) rating A–B
Structural verification: the ground-floor wall works at 6.7% of its capacity
| Factored load per storey (1.35·G + 1.50·Q) | 13.3 kN/m² |
| Tributary width of the façade wall | 2.70 m |
| Storeys supported above ground floor (4 + roof) | 5 |
| Axial load from slabs N₁ = 13.3 × 2.70 × 5 | 179 kN/m |
| Self-weight of the wall (13 m elevation, factored) | 60 kN/m |
| Design axial load N_Ed | 239 kN/m |
| Resisting section (2 printed leaves × 70 mm) | 1,400 cm²/m |
| Design strength f_cd = 0.85 × 90 / 1.5 | 51.0 MPa |
| Reduction for slenderness and eccentricity Φ = 0.50 | × 0.50 |
| Design capacity N_Rd = Φ · A · f_cd | 3,570 kN/m |
Simplified Eurocode-type verification (EC2/EC6 format) with conservative assumptions; the execution design develops it with a full calculation, signed and professionally endorsed (visado).
- Design action N_Ed (loads already factored)
- 239 kN/m
- Design capacity N_Rd of the double printed wall
- 3,570 kN/m
- Safety factor, in addition to the standard partial factors already included
- FS ≈ 15
Put another way: each metre of wall could carry, at characteristic failure, the weight of more than 1,200 tonnes. The whole building demands only a small fraction of that.
Belt and braces: how risk is eliminated
Proven hybrid structure
The printed walls work together with in-situ reinforced concrete slabs, perimeter ring beams and conventional foundations, all calculated to the standards in force. The printed part is never on its own: the building is a redundant system.
Fire, earthquake and durability
Concrete is non-combustible (Euroclass A1) and the solid double wall provides fire resistance well above that required. In low-seismicity zones, the mass of the system improves acoustic and thermal performance.
Less human error
The geometry comes from the digital twin with millimetre precision: no setting-out errors, no badly executed joints, no dependence on the skill of the day. The machine repeats the standard 24 hours a day.
What if the printer fails on site? Two printers in parallel, a hybrid structure with conventional slabs and a responsible turnkey contractor: OBRALIA 3D.
What the investor gains and what the architect gains
- Programme: structure 45% fasterReference project: 13 months of total works against 19–24 for the traditional route, to start invoicing sooner.
- Almost zero wasteMaterial is deposited only where the model requires it: 99% less rubble and up to 50% less material (TectorPrint).
- Formal freedom at no extra costCurves, lattices, textures and tree-like columns cost the same as a straight line: the façade is the structure.
- Fewer simultaneous trades2 operators per printer and fewer subcontractors: less occupational risk, less coordination, fewer deviations.
Every doubt, answered with facts
Can it support a multi-storey building?
Wallenhausen (3), Tor Alva (4, load-bearing), Suzhou (5) and Wave House have demonstrated it since 2015. The reference building's wall works at 6.7% of its capacity.
Is it regulated and insurable?
ISO/ASTM 52939:2023, multi-storey AC509, UL 3401; buildings approved in DE/BE/NL/US; in Spain via performance-based CTE + DIT + OCT and seguro decenal (ten-year liability insurance).
Is the material reliable?
90 MPa mortar, 3× conventional concrete, with specimens from every working day and layer-by-layer traceability.
Is it an immature technology?
30 years of R&D, shareholders including Holcim, GE, CEMEX and PERI, more than $450 M raised by ICON and a published international standard.
Does anyone already live in one?
5 families in Wallenhausen since 2021, 100 homes on sale in Texas, 52 homes in Kenya, a data centre in Heidelberg.
What if the printer fails on site?
Two printers in parallel, a hybrid structure with conventional slabs and a responsible turnkey contractor: OBRALIA 3D.
Verifiable sources
The claims in this dossier come from public sources consulted in September 2026 and from manufacturer tests. We invite architects and investors to check them.
| Source | Content |
|---|---|
| COBOD International | cobod.com · Wave House, Kamp C, shareholding structure (PERI 2018 · GE, CEMEX, Holcim 2022) |
| PERI 3D Construction | peri3dconstruction.com · Wallenhausen: 380 m², 72 h, homes let |
| ETH Zürich | ethz.ch · Tor Alva: 30 m, 4 storeys, integrated reinforcement (May 2025) |
| Dezeen | dezeen.com · “World's tallest 3D-printed tower unveiled in Switzerland” (21-05-2025) |
| Holcim | holcim.com · investment in COBOD, TectorPrint, Striatus and Phoenix bridges |
| 14Trees (Holcim + BII) | 14trees.com · Mvule Gardens: 52 homes, EDGE Advanced certification (IFC) |
| Wolf Ranch / ICON / Lennar | wolfranchbyhillwood.com · iconbuild.com · Genesis Collection: 100 printed homes |
| VOA News | voanews.com · Wolf Ranch: prices $450–600k, owner testimonials |
| ISO / ASTM | iso.org · ISO/ASTM 52939:2023 Additive manufacturing for construction |
| ICC Evaluation Service | icc-es.org · AC509: 3D Automated Construction Technology (2021, multi-storey revision); ESR-4623 |
| TIME / ArchDaily | time.com · archdaily.com · WinSun: 5-storey block, Suzhou 2015 |
| Guinness World Records / Dubai | Printed municipal offices of 640 m² (2019) |
| Grand View Research | grandviewresearch.com · printed construction market: $4,180 M by 2030 |
| IETcc–CSIC | dit.ietcc.csic.es · Documento de Idoneidad Técnica (DIT, technical suitability document): assessment of innovative systems in Spain |
| AENOR / Holcim España | holcim.es/certificaciones-hormigon · ISO 9001, ISO 14001, CE marking and RD 163/2019 per plant |
| COSMOS 3D · Cosmos Proof | Official manufacturer tests (Katz / IT3D group) at LAEES-UFMG: wall failure NBR 16868:2020 (964 kN · 618 kN/m), acoustics NBR ISO 12354-1 (Rw 64 dB), thermal shock NBR 15575 (10/10 cycles) and water tightness (7 h · 3.0 L/min/m² · 50 Pa · 0.00 m² of dampness). Reports available on request. |
Would you like the manufacturer's reports, or to have an engineer review your project?
Test reports are available on request. Tell us about your case and an OBRALIA 3D engineer will reply within one working day.