What the RSJ Cost Calculator Does
Steel prices change with global markets, and RSJ project costs involve far more than the beam itself. Our Cost Calculator gives you a realistic all-in estimate for 2026 by combining current UK and Poland steel prices with typical delivery charges, structural engineer fees, Building Control costs and installation labour. Whether you are removing a single wall or planning a large extension, the calculator helps you budget confidently before you request formal quotes.
How to Use the Calculator
- Select your country – Choose UK or Poland to apply the correct price base, VAT rate and typical labour costs.
- Pick the beam size and length – Enter the section and total length including bearing. The calculator looks up the 2026 price per metre.
- Add delivery and finish – Select standard or express delivery, and choose a finish such as primed, shot-blasted or galvanized.
- Include professional fees – Toggle structural engineer drawings and Building Control approval to see the total project cost rather than just the steel price.
Why Cost Estimation Matters
Many homeowners underestimate RSJ projects because they only look at the steel price. In reality, the beam often represents just 20–30 % of the total cost. Engineer fees, acrow prop hire, padstones, making good plasterwork and decoration can all add up. A reliable upfront estimate prevents budget overruns, helps you compare supplier quotes fairly, and gives you leverage when negotiating with contractors. It also highlights why cutting corners on professional design is a false economy.