The apprentice wage is the part everyone quotes, and it is the smallest line on the bill. Add the National Insurance, the off-the-job training hours, and the one nobody writes down: among UK construction employers who train, 26% of the spend is the wages of the people delivering it, the highest share of any sector.
Then there is keeping them. In England in 2024/25, fewer than half of plumbing and domestic heating apprentices achieved their qualification. What an apprentice really costs in the first year, what to pay a qualified electrician or heating engineer so they stay, what the supervision rules actually say on a gas job or a consumer unit, and which of the rules everyone repeats on site are law.