Ibstock, the UK's largest brickmaker, just issued a profits warning that functions as a seismograph for the entire housebuilding sector. UK brick market volumes fell 17% year-on-year in July and August. Third-quarter sales came in 22% below expectations, forcing a one-fifth production cut versus plans set as recently as August. Full-year top-line earnings will land in the mid-£40m range against City expectations near £60m. The share price dropped 11% to virtually its lowest since the company's 2015 relisting. The numbers are ugly, but the structural picture is worse. Housebuilders across the board are retreating into what they call "financial discipline" — corporate code for freezing expansion and grinding costs. Berkeley Homes, focused on south-east England, said six months ago it would stop buying new land and hiring new staff. This is not a pause; it is an industry battening down for a prolonged downturn. The root cause is well understood: the Iran war reversed interest rate expectations. The Bank of England is expected to raise rates this week, and the market is already pricing in further increases. Mortgage affordability is deteriorating, and builders face rising regulatory costs against flat new-house prices. The squeeze operates from both ends simultaneously. John Healey's Your First Home scheme — the government's answer — is welcome in principle but limited in practice. Transaction caps ensure it is deliberately smaller than Help to Buy, because the Treasury cannot afford to pour demand stimulus into an inflationary environment. The April launch date creates a perverse incentive: qualifying buyers who can wait five months for discounted loans will do exactly that, suppressing demand in the interim. Ibstock CEO Joe Hudson flagged this explicitly. Healey also announced a freeze on new building regulations this parliament (safety-critical changes excepted), a meaningful concession to builders who have complained about mounting compliance costs. But existing regulations stay in place, so the relief is marginal rather than transformative. The Office for Budget Responsibility forecasts 1% GDP growth in 2027. In that environment, Your First Home will be, as Peel Hunt puts it, "modestly helpful." The real unlock remains lower borrowing costs, and nobody knows when those arrive. The government's 1.5 million new homes target for this parliament is not officially dead, but the arithmetic is brutal. Every quarter of delay compounds the shortfall. What emerges is a familiar pattern: a sector whose fortunes are dictated almost entirely by the cost of money, facing a government whose fiscal room to stimulate demand is constrained by the same inflationary pressures that killed the housing boom. The brickmaker's profits warning is a lagging indicator of a problem that started with geopolitics and will only end with rates. Everything in between is palliative.