A bag of cement cost N9,000 in December. It now costs N13,000. That increase will reach you even if you aren't building anything.

The price of a 50kg bag of cement has hit N13,000 in parts of Nigeria following fresh price adjustments by Dangote Cement and BUA Cement. In April it was N12,000. In January it was N10,000. In December it was N9,000. That is a 44 percent increase in five months.

If you're building a house, you already know. If you're not, here is when you'll find out.

Your landlord will. Block makers have already raised the price of a nine-inch block from N750 to N800. Contractors are revising quotes on projects mid-build. Developers who locked in prices at the start of the year are absorbing losses or passing them on. The person at the end of that chain is whoever needs to rent something in Lagos, Abuja, or any state capital in the next six months.

This is how cost increases move through Nigeria's housing market. They rarely announce themselves. They arrive as a letter slipped under a door, or a conversation your landlord has been preparing for, or a quote from a contractor that comes back 30 percent higher than the one they gave you eighteen months ago. The cement price moved first. The block price moved next. The contractor's rate will follow. The rent review comes last. By the time the tenant feels it, the original cause is two steps removed.

Dangote and BUA together control enough of Nigeria's cement market that their pricing decisions aren't really market decisions. They are announcements. The market adjusts to them. Nigeria has surplus cement capacity. The factories exist. Production can run at scale. Policy analysts have been calling for competition reforms in the sector for years, arguing that import licences would introduce the kind of competitive pressure the current structure eliminates entirely. The government has declined that route. The price rises, and the market finds no floor.

Manufacturers cite energy costs. Fuel prices affect production. Transportation adds its own margin. Those explanations are true. They are also incomplete. When the most concentrated market in the country uses input cost increases as cover for price adjustments that consistently exceed those input costs, the explanation becomes a justification. What a financial analyst told Legit.ng this week is worth repeating: Nigeria cannot be left at the mercy of a small number of manufacturers who effectively set prices without competition.

The person in this story is the one who looked at their savings in January and thought they could finally fix the roof this year. They had the money. The money is still there. It just doesn't reach as far as it did four months ago.