Short answer: a reinforced concrete cantilever wall runs roughly ₱9,000–₱16,000 per linear metre at 1.5 m retained height, ₱16,000–₱28,000 at 2.5 m, and ₱30,000–₱55,000 at 4 m. Notice that the price more than doubles when the height does. That is not a markup — it is geometry, and understanding it is the difference between a budget that holds and one that doesn't.
Earth pressure is triangular. Total thrust grows with the square of the retained height; the overturning moment grows with the cube. Go from 2 m to 3 m — 50% taller — and the thrust rises 125% while the overturning moment rises 238%. The wall answers with a thicker stem, a much wider base, and far more steel.
Prices a wall by type and retained height, shows the thrust and overturning moment behind that price, and flags what drainage failure or a surcharge above the wall does to both.
Per linear metre, supplied and built, as AEDO 2026 planning ranges for Negros Oriental and nearby provinces.
| Type | 1.5 m | 2.5 m | 4.0 m | Best suited to |
|---|---|---|---|---|
| Grouted CHB gravity | ₱5,500–9,000 | — | — | Low garden walls only, up to ~1.2–1.5 m |
| RC cantilever | ₱9,000–16,000 | ₱16,000–28,000 | ₱30,000–55,000 | The default for boundaries and cut slopes |
| RC with counterforts | — | ₱19,000–33,000 | ₱34,000–60,000 | Becomes economic above roughly 4 m |
| Gabion basket | ₱6,000–11,000 | ₱11,000–19,000 | ₱20,000–37,000 | Free draining, where base width is available |
| Grouted riprap / masonry | ₱5,000–9,000 | ₱9,500–17,000 | — | Slope faces and erosion protection |
Excluded from all of these, and routinely excluded from quotes too: excavation and disposal of spoil, dewatering, temporary shoring where the cut is unstable, the soil investigation, and the design itself. On a difficult site those can add 20–40%. The quote checker covers how to get exclusions written down before you sign.
Water Fails More Walls Than Soil Does
A drained granular backfill with functioning weep holes lets water out. Omit it, or let it clog with fines because no filter was used, and the backfill saturates. Hydrostatic pressure is then added to earth pressure and the total thrust roughly doubles.
This is why walls fail during or just after a long rainy spell, not on the day they were loaded — the load that broke them was never in the original design. Weep holes, a granular drainage layer and a filter fabric are the cheapest structural elements on the whole wall, and the first things a low bid quietly drops.
Retaining walls are expensive because they fight the ground. Sometimes the cheaper engineering is not to fight it.
Which of these applies is a design question, and it is much cheaper to answer before the earthworks than after. If you are still choosing a site, the setback rules often interact with this — the wall may be forced by where you are allowed to build.
Earth pressures use Rankine active theory with a soil unit weight of 18 kN/m³ and a level backfill, the same basis as our retaining wall stability calculator. They are screening values: a real design also checks sliding, bearing pressure and global stability, and uses soil parameters established by investigation rather than assumed. Cost bands are AEDO 2026 planning ranges for Negros Oriental and nearby provinces — market estimates for judgement, not quotations. Access, haul distance and dewatering move them more than materials do.
How much does a retaining wall cost per metre in the Philippines?
As a 2026 planning range, a reinforced concrete cantilever retaining wall runs about 9,000 to 16,000 pesos per linear metre at 1.5 metres of retained height, roughly 16,000 to 28,000 pesos at 2.5 metres, and 30,000 to 55,000 pesos at 4 metres. Gabion and riprap solutions are cheaper per metre where the site suits them, and a grouted CHB gravity wall is cheapest of all but is only appropriate at low heights. The reason the figures climb so steeply is that the load on the wall grows with the square of the retained height, so a taller wall needs a thicker stem, a wider base and far more reinforcement, not simply more of the same wall.
Why is a 3 metre retaining wall so much more expensive than a 2 metre one?
Because earth pressure is triangular, so the total thrust on the wall is proportional to the height squared and the overturning moment is proportional to the height cubed. Going from 2 metres to 3 metres, a 50 percent increase in height, raises the thrust by about 125 percent and the overturning moment by about 238 percent. The wall answers that with a thicker stem, a much wider base and heavier reinforcement, and it also needs a deeper excavation, which is why cost roughly doubles rather than rising by half.
Can I build a retaining wall out of CHB?
At low heights, yes, if the cells are reinforced and fully grouted and the wall has a proper reinforced concrete footing, drainage and weep holes. Beyond roughly 1.2 to 1.5 metres of retained height a hollow block wall becomes the wrong tool: the section is too thin to resist the bending, and grouted masonry cannot economically develop the reinforcement a cantilever needs. Most of the failed garden walls we are called to look at are ungrouted CHB fences that someone backfilled against, which turns a fence into a retaining structure it was never designed to be.
What makes retaining walls fail in the Philippines?
Water, more often than soil. A drained granular backfill with functioning weep holes lets water out; when the drainage is omitted or clogs, the backfill saturates and hydrostatic pressure is added to earth pressure, which can roughly double the total thrust on the wall. That is why so many walls fail during or just after a prolonged rainy spell rather than on the day they were loaded. The other common causes are a base that is too narrow to resist overturning, no key or insufficient embedment against sliding, and backfill placed and compacted before the concrete has gained strength.
Do I need an engineer for a retaining wall?
For anything retaining more than about a metre, yes, and for a building permit the structural plans must be signed and sealed by a PRC-licensed civil engineer regardless. A retaining wall is one of the few residential structures where failure is sudden rather than gradual and where the consequences reach beyond your own property line to a neighbour below. The design also depends on soil properties that have to be established rather than assumed, because the angle of internal friction and the drainage characteristics of the retained material change the required section substantially.
Is a gabion wall cheaper than concrete?
Usually yes per linear metre, and gabions have two further advantages in Philippine conditions: they are free draining, which removes the hydrostatic problem that fails so many concrete walls, and they tolerate some settlement without cracking. They need space, because a gabion structure is a gravity wall and its base width is a large fraction of its height, and they need durable wire, since coating failure in a coastal or aggressive environment shortens the life of the whole structure. On a tight boundary where there is no room for a wide base, a reinforced concrete cantilever is often the only option that fits.
Half the retaining walls we are asked to quote turn out not to be the cheapest solution for the site. The design decision — wall, terrace, regrade, or move the building — is worth far more than the rate per metre.