A 5-bedroom duplex in Nigeria typically needs 8,000 to 12,000 blocks — more than a bungalow because a duplex has two floors and extra structural walls. Alongside the blocks you’ll need roughly 1,300–1,800 bags of cement for the blockwork and setting. At 2026 block prices, the blocks alone come to somewhere around ₦4M–₦7M. The exact count always depends on your drawings — wall height, room sizes and block type all move the number — but this gives you a reliable planning figure. (Current as of July 2026.)
“How many blocks will I need?” is one of the first real questions every self-builder asks, because blocks are one of the biggest single material line items — and the quickest way to blow a budget is to under-order and pay top price for the last few thousand. So let’s answer it properly for a 5-bedroom duplex, show you how the figure is worked out, and put a 2026 cost to it.
How many blocks does a 5-bedroom duplex need?
Plan for 8,000 to 12,000 blocks. A duplex uses far more than a single-storey house of the same bedroom count because you’re walling two floors, plus the staircase core, boundary and internal partitions. Where you land in that range depends on the design — a compact, efficient layout sits nearer 8,000; a large duplex with a boys’ quarters, thick 9-inch external walls and high ceilings pushes toward 12,000 or beyond.
Worth knowing: Only your architectural drawings give an exact number. A quantity surveyor calculates it from the total wall area (length × height of every wall) divided by the blocks-per-square-metre for your block size — roughly 10 blocks per m² for standard 9-inch blocks. Everything below is a planning estimate, not a substitute for a proper take-off.
Blocks by building type (for comparison)
If you’re weighing options, here’s roughly how a 5-bedroom duplex compares to other common builds in Nigeria.
| Building type | Approx. blocks needed |
|---|---|
| 2-bedroom flat | 2,200–3,000 |
| 3-bedroom flat | 2,700–3,600 |
| 3-bedroom bungalow | 2,700–3,300 |
| 4-bedroom duplex | 6,000–9,000 |
| 5-bedroom duplex | 8,000–12,000 |
What the blocks will cost in 2026
Block prices move with cement, so treat these as a current snapshot, not a fixed rate. In mid-2026, moulded blocks commonly run about ₦450–₦700 each depending on type (6-inch vs 9-inch), location and whether you buy from a commercial block industry or mould on site. Do the simple maths:
| Blocks | At ₦450 each | At ₦700 each |
|---|---|---|
| 8,000 | ₦3,600,000 | ₦5,600,000 |
| 10,000 | ₦4,500,000 | ₦7,000,000 |
| 12,000 | ₦5,400,000 | ₦8,400,000 |
For the current price of blocks, cement and rods, check our Nigerian Construction Cost Tracker, which we refresh each quarter. Moulding your own blocks on site can cut the per-block cost, but factor in cement, sharp sand, labour and quality control before assuming it’s cheaper.
Don’t forget the cement
Blocks are only half the blockwork story. A 5-bedroom duplex needs roughly 1,300–1,800 bags of cement across the build — for moulding blocks (if self-moulding), laying/setting them in mortar, and rendering. If you’re buying blocks ready-made, your setting-and-rendering cement is lower, but it’s still a major line item. Our full breakdowns put real 2026 numbers to the whole build.
Costing a full duplex? Don’t stop at the blocks. See the complete stage-by-stage build cost in our cost of building a 5-bedroom duplex guide, and browse every price in the complete cost library.
Watch out: Order blocks in planned batches, not all at once — but confirm your supplier can hold the price. Builders who under-estimate end up buying the final few thousand blocks at whatever the market charges that month, often after prices have jumped. A proper take-off from your drawings prevents both over- and under-ordering.
Frequently asked questions
How many blocks are needed to build a 5-bedroom duplex in Nigeria?
Roughly 8,000 to 12,000 blocks. A duplex needs more than a single-storey house because it walls two floors plus a staircase core. Your exact number comes from a quantity take-off based on your architectural drawings.
How many bags of cement for a 5-bedroom duplex?
Around 1,300–1,800 bags across blockwork, setting and rendering, varying with design and whether you mould your own blocks. Foundation, decking and finishing add their own cement requirements on top.
How much do the blocks cost?
At about ₦450–₦700 per block in 2026, 8,000–12,000 blocks come to roughly ₦4M–₦7M. Check the current block price before ordering, since it moves with cement.
Is it cheaper to mould blocks on site?
It can be, since you cut the supplier’s margin — but you take on cement, sand, labour and quality-control costs and risk. For large builds many people still buy from a reputable block industry for consistency. Compare a real quote both ways.
Sources & method: Block-count ranges from Nigerian construction estimating sources (The Architect, Priceniche, RealEstateKo, 2025–2026); block/cement pricing from current market. Estimates only — a quantity surveyor’s take-off from your drawings gives the exact figure. Last updated: July 2026. Journalists and researchers may cite this with attribution to LandsofNigeria.com.
