🇬🇩 Grenada · Standards & approvals · Updated 2026
Foundation requirements in Grenada
Foundations in Grenada are conventionally taken to about 0.60 m below ground level, 400 mm wide, as a strip foundation. The ground does not freeze here, so depth is governed by reaching firm bearing material and getting below seasonal moisture movement, not by frost.
Foundation requirements is one of the requirements that decides what your building actually has to be — and therefore what it costs. This page sets it out for Grenada specifically, from that country's own construction conventions and site conditions, with the practical sequence to follow and the cost consequences spelled out.
Requirements in Grenada
| Requirement | Value | Why it matters |
|---|---|---|
| Foundation type | Strip | A strip footing under each loadbearing wall — the conventional and cheapest solution on competent ground. |
| Depth to underside | 0.60 m | Set by bearing capacity and conventional practice. |
| Footing width | 400 mm | Spreads the wall load to an intensity the soil can carry. Widen it on soft ground rather than deepening it. |
| Concrete mix | 1:2:4 | The conventional footing mix here. Structural elements use a richer mix. |
| Blinding | 50 mm | A clean, level surface to set reinforcement and formwork on. Cheap, and it stops soil contaminating the structural pour. |
| Hardcore under slab | 150 mm | Compacted fill that supports the ground slab and breaks capillary rise. |
| Damp-proof course | Required | Stops ground moisture rising through the wall. Omitting it is one of the most expensive mistakes possible to fix later. |
| Seismic band | low | Nominal reinforcement and normal detailing. |
What to do, in order
- 01Get the ground investigated
A trial pit or borehole is the cheapest insurance on the whole project. It tells you the bearing capacity and whether 0.60 m actually reaches competent material in your plot, which no general figure can.
- 02Confirm the depth against frost and moisture
Frost is not a factor in Grenada. Depth is about reaching firm material and getting below the zone of seasonal shrink and swell, which matters greatly on clay soils.
- 03Size the footing to the load
A 400 mm strip suits typical single-storey loadbearing walls on competent ground. Two storeys, poor ground or concentrated loads all require it widened or reinforced.
- 04Excavate, blind and inspect
Most authorities inspect at foundation stage before concrete is placed. Work covered before inspection is routinely ordered to be opened up again.
- 05Place, compact and cure
Cure the concrete properly. A footing that dries out instead of curing reaches a fraction of its design strength, and nothing later fixes it.
What it does to the cost
- —Substructure typically runs 12–18% of construction cost, and depth drives it directly — going from 0.6 m to 0.60 m raises excavation, concrete and disposal together.
- —Foundations are the item most often re-priced after work starts, because the drawing shows a footing and the ground shows something else.
- —Low seismic risk keeps substructure reinforcement to nominal quantities, which is a real saving against seismic regions.
Price the building these rules describe
Upload your drawings and get an itemised bill of quantities in XCD ($), measured to the SMM7 standard Grenada professionals use.
Generate my Grenada BoQFoundation requirements in Grenada — frequently asked
What are the foundation requirements in Grenada?
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Foundations in Grenada are conventionally taken to about 0.60 m below ground level, 400 mm wide, as a strip foundation. The ground does not freeze here, so depth is governed by reaching firm bearing material and getting below seasonal moisture movement, not by frost.
Foundation type in Grenada — what is it?
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Strip. A strip footing under each loadbearing wall — the conventional and cheapest solution on competent ground.
How does this affect what the building costs?
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Substructure typically runs 12–18% of construction cost, and depth drives it directly — going from 0.6 m to 0.60 m raises excavation, concrete and disposal together. Foundations are the item most often re-priced after work starts, because the drawing shows a footing and the ground shows something else. Low seismic risk keeps substructure reinforcement to nominal quantities, which is a real saving against seismic regions.
What is the first thing I should do?
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Get the ground investigated: A trial pit or borehole is the cheapest insurance on the whole project. It tells you the bearing capacity and whether 0.60 m actually reaches competent material in your plot, which no general figure can.
Is this legal or code advice?
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No. These are conventional practice and planning allowances, compiled so a cost estimate is realistic rather than confidently wrong. The building authority in your municipality, and a professional registered in Grenada, are the only authorities on what your project must comply with.