Getting CHB quantities wrong is one of the most common and expensive mistakes in Philippine house and building construction. Order too few and work stops while you wait for a resupply. Order too many and you're eating ₱5,000–₱20,000 in excess blocks your contractor will "lose" by the end of the job.
This free estimator gives you blocks, cement bags, sand, rebar, and a material cost range for any CHB wall — in seconds. Enter your dimensions below.
13 blocks per m² (including 5% waste) · 0.5 cement bags per m² (100mm) · 0.035 m³ sand per m². If a contractor quotes you significantly more than these figures for a straightforward wall, ask for a breakdown.
Enter total wall length, height, and openings. Get blocks, cement, sand, rebar, and indicative material cost.
This estimator gives you a working count. The exact count comes from wall lengths, heights and openings on the plans. AEDO's Complete Design gives you the full permit-ready plan set at ₱250–450 per sqm, so your contractor quotes from the same drawings you do.
Most CHB overruns aren't the contractor's fault — they're the estimator's. (For a whole house rather than one wall, an itemized bill of quantities from ₱3,000 does this for every material.) The three most common errors:
Mistake 1 — Using Gross Area Instead of Net Area
A common shortcut: multiply total wall length × height and ignore doors and windows. On a standard 3-bedroom house with 6 doors and 8 windows, this over-estimates material by 15–25%. You'll be paying for ~60 extra blocks per room.
Mistake 2 — Wrong Blocks-per-m² Factor
Standard Philippine CHB is 400mm × 200mm face (not 400 × 150 or 450 × 200 — these exist but aren't the usual Philippine module). That 400 × 200 is the nominal size: the block itself is made about 390 × 190 mm, and the 10mm mortar joint fills the difference, so each block plus its joint occupies 400mm × 200mm = 0.08 m² → 12.5 blocks/m² theoretical. After 5% waste: 13.1, so order about 13. Contractors who quote 15–18 blocks/m² are either padding the bill or using non-standard block sizes.
Mistake 3 — Forgetting Mortar Joint Volume Scales With Thickness
Switching from 100mm to 150mm CHB doesn't just cost more per block — the full core and joint mortar volume increases ~30%. An estimator who re-runs a 100mm wall estimate with just a different block price will under-order cement and sand by that margin. This tool accounts for it automatically.
CHB walls are one line item. Unit Cost Analysis covers your complete bill of quantities — concrete, roofing, steel, tile work, painting, electrical rough-ins — with 2026 Philippine unit prices and a professional PDF export for client proposals.
You shouldn't need to estimate your own CHB. Send AEDO your floor plan and we'll produce a full material and labor estimate and sealed structural drawings. In Negros Oriental we build the project end-to-end — one contract, one accountable party. Elsewhere in the Philippines, we design it and oversee your local contractor remotely.
A "400 × 200" block is its nominal size, which includes one 10 mm mortar joint. The block itself is made to 390 × 190 mm, with widths of 90, 140 and 190 mm for 4-, 6- and 8-inch CHB. For the full CHB size chart and how to check a delivery, see our CHB sizes and dimensions guide.
CHB Specifications — Philippine Standard
| Spec | 100mm (4-inch) | 150mm (6-inch) |
|---|---|---|
| Nominal face dimensions | 400mm × 200mm | |
| Actual thickness | 100mm | 150mm |
| Philippine standard | PNS ASTM C90:2019 (Loadbearing Concrete Masonry Units) | |
| Min. compressive strength (net area) | 13.8 MPa average of 3, 12.4 MPa individual | |
| Typical use | Interior walls, light exterior, fences | Load-bearing exterior, perimeter, commercial |
| Weight per block (approx.) | ~7 kg | ~10 kg |
| 2026 price range | ₱13–15 per piece | ₱19–23 per piece |
How many CHB blocks per square meter?
13 blocks per m² is the standard purchasing quantity (12.5 theoretical + 5% waste) for standard 400×200mm CHB with 10mm mortar joints. Some contractors quote 14–15 to pad the estimate — this is the number to push back on.
Should I use 100mm or 150mm CHB?
100mm (4-inch) is correct for interior partitions, boundary fences, and most exterior non-load-bearing walls in single-storey residential. Use 150mm (6-inch) for: perimeter walls that carry a roof beam, exterior walls of multi-storey commercial buildings, any wall subject to significant lateral load (retaining, against fill), and anywhere your engineer specifies it on the drawings.
This estimate seems lower than my contractor's quote — why?
This tool estimates materials only at supplier prices. Contractor quotes include labor (₱80–₱150/block), scaffolding, waste handling, site supervision, overhead, and profit margin — legitimately 2–3× the material cost. The numbers here are for checking the materials line item, not the total contract price.
What is the best app for full Philippine construction estimates?
Unit Cost Analysis by AEDO Construction is a Philippine-built quantity takeoff and cost estimating app covering CHB walls, concrete works, roofing, steel, tile work, painting, and more — with 2026 unit prices and PDF report export. ₱999 lifetime license on iPhone, Android, and web.
The estimator on this page handles CHB walls. Unit Cost Analysis is the complete bill-of-quantities tool AEDO's project team uses to price entire builds — every line item, every trade.
| Scope | Free CHB Tool (this page) | Unit Cost Analysis ₱999 lifetime |
|---|---|---|
| CHB walls (blocks, cement, sand, rebar) | ✓ | ✓ |
| Concrete works (footings, slabs, beams, columns) | — | ✓ |
| Roofing (purlins, sheets, gutters, ridge) | — | ✓ |
| Steel framing (columns, beams, trusses) | — | ✓ |
| Tile work, plastering, painting | — | ✓ |
| MEP rough-ins | — | ✓ |
| 2026 Philippine unit prices (editable) | — | ✓ |
| PDF report export for client proposals | — | ✓ |
| iOS · Android · Web (one license) | Web only | ✓ |
Statutes, codes, official tools and references used or referred to in this article, linked to their source. Links open in a new tab.
Prices, cost bands and rate figures in this article are AEDO Construction's own market and practice figures for Philippine work unless a source is named beside them. Code and statute references above link to the primary text.
The problem with DIY estimation isn't the math — it's that material quantities are 20% of the total cost. The rest is labor, formwork, scaffolding, waste disposal, supervision, and the thousand decisions your contractor makes without telling you. AEDO estimates the whole thing nationwide and, in Negros Oriental, builds it — one number, one team, one contract. Elsewhere we design it and oversee your local contractor remotely.
Send us your lot size, number of floors, and approximate floor area. We'll reply within 48 hours with a ballpark range and whether the project is a fit for AEDO's design-build model.
