--- title: "Precast Concrete" description: "Columns, beams, hollowcore floors, stair cores and architectural façade panels, taken as one package from the foundations to the roof." updated: "2026-10-12" url: "https://www.petruf.ie/services/precast-concrete" --- # Precast Concrete > Columns, beams, hollowcore floors, stair cores and architectural façade panels, taken as one package from the foundations to the roof. Precast rewards decisions made early and punishes ones made late. Panel sizes, joint positions and crane reach are design questions, not delivery questions, and they are settled while the arrangement is still on a sketch. We design and detail precast frames for manufacturers and contractors anywhere in Ireland, from our office in Newbridge, Co. Kildare. Frames are modelled in Allplan Precast and analysed in SCIA Engineer, to the Eurocodes with their Irish National Annexes and to the product standards the factory works to. The model goes to the rest of the design team as IFC, and the drawings as DWG and PDF. Every drawing that leaves the office has been checked and signed by a chartered engineer. ## What we do ### 3D BIM Modelling and Detailed Layouts Advanced BIM modelling to create detailed layouts for precast concrete elements, ensuring accuracy in manufacturing and installation. ### Early Project Stage 3D Modelling 3D models at early project stages, to visualise precast concrete elements and integrate them into the design. ### Manufacturing Drawings and Production Information Detailed drawings and specifications for the production of precast elements, ensuring all components meet required standards. ### Manufacturing Layouts and CNC Files In depth analysis and design of precast concrete elements, tailored to meet the specific needs of the project. ### Precast Detailing and Fabrication Drawings Detailed fabrication drawings for each precast component, facilitating efficient production and assembly on site. ### [Feasibility Studies](https://www.petruf.ie/services/consulting-and-compliance/feasibility-studies) Whether precast suits the building, its grid and its programme, checked before the design is fixed. ### Project Guidance and Recommendations Expert advice on how to optimise precast concrete use, balancing cost, performance and design flexibility. ### Project Management and Coordination Managing the entire precast concrete process, from design and fabrication to delivery and installation. ### [Value Engineering](https://www.petruf.ie/services/structural-engineering/value-engineering) In situ and steel schemes reviewed for precast, with fewer unit types, repeating connections and the alternative designed and signed for. ## The questions that come first ### What is precast concrete, and where does it make sense? Precast is concrete cast in a factory and delivered ready to install, rather than poured and cured on site. It suits repetition, long spans and constrained sites, because the work happens under cover while the site is still being prepared. Where a frame is one of a kind and geometrically awkward, in situ concrete often remains the better answer. ### Is precast cheaper than in situ concrete? Not by the cubic metre. Precast mixes are usually richer, and the element carries the cost of the mould and the delivery with it. What precast saves is time and everything time costs: fewer trades on site, no formwork or curing in the critical path, and a programme that does not move with the weather. On long spans and repeated floors it also tends to be cheaper by the square metre. ### How much faster is a precast frame? Installation is measured in days where an in situ equivalent is measured in weeks, because the curing has already happened in the factory. The saving is real but it is not free: it is bought with design time up front, since the elements have to be finished and scheduled before the first one is cast. ### What is hollowcore, and what spans does it suit? Hollowcore is a prestressed floor unit with voids running through it, which takes weight out of the slab without taking away its capacity. The voids are what let it span far further than a solid slab of the same depth, so it suits apartment and commercial floors where the span is long and the layout repeats. It also uses less concrete and steel than the in situ floor it replaces. ### What is the lead time on precast, and when must the design be frozen? The factory needs the design settled before it can schedule production, so the freeze point comes earlier than on an in situ frame. That is the single most important thing to know about building in precast: the programme saving on site is paid for with decisions made early, and the earlier the layout, the loads and the openings are fixed, the more of that saving survives. ### Who designs the precast connections? Somebody has to, and it should be agreed in writing before anything is cast. A frame designed by one engineer and detailed by another is where connections go missing, because each assumes the other has it. Where the analysis, the detailing and the element schedules are done by the same office, there is no handover for a connection to fall into. ### What does a precast designer need to start? The architectural layouts, the loads, the stability strategy and the openings, plus whatever the mechanical and electrical design needs to pass through the frame. Getting the penetrations in before the elements are cast is the whole point: a hole drilled on site into a prestressed unit is a repair, not a detail. ### Which standards do you design precast to? The Eurocodes with their Irish National Annexes: IS EN 1990 for the basis of design and IS EN 1992 for the concrete. Alongside them, the product standards the factory makes the elements to: IS EN 13369, the common rules for precast concrete products, IS EN 1168 for hollowcore slabs, IS EN 14992 for wall elements and IS EN 14843 for stairs. Designing to the product standard as well as the Eurocode means the element on the drawing is the element the factory makes. ### What software do you use, and what files do you deliver? Frames are modelled in Allplan Precast and analysed in SCIA Engineer. The model is issued as IFC, so the architect, the services engineers and the contractor can bring it into their own software, and the drawings are issued as DWG and PDF. ### Who checks the precast drawings before they are issued? A chartered engineer, in the same office that designed the frame. Every drawing is checked and signed before it goes out, so a manufacturer gets drawings with a named engineer behind them, rather than a detailing service working to somebody else's design. ### Can precast be changed once production has started? Only at a cost, and the cost rises with every element already cast. A change to a layout that has reached the factory means re-scheduling, re-detailing and sometimes remaking units, which is why precast rewards decisions made early and punishes ones made late. Changes are handled far more cheaply while the model is still the only thing built.