Is My Site Buildable in Ireland? The Five Checks That Decide It
On this page
Planning status, access, soil, water, wastewater. Any one of these can kill a sale-agreed purchase.
Five things decide whether a site is buildable in Ireland: planning status, road access, ground conditions, water supply, and wastewater disposal. Run all five checks before you sign contracts. Planning is the question you check first (does the county development plan allow a one-off house on this site?); wastewater is the question most buyers forget about until the engineer says no. EPA Code of Practice for Domestic Wastewater Treatment Systems (2018, updated 2021) is the controlling document for rural sites. Most rural sites need a treatment system plus percolation area; setbacks from wells, houses, and boundaries can make a small site impossible. A site assessment (soil test, percolation test, water yield test) costs €1,500–€4,000. Engineers typically add €300–€600 for a desktop feasibility study. Spend that before sale-agreed, not after.
TL;DR
A site is buildable in Ireland if it has planning permission (or can get it under the county development plan), reasonable road access, a soil class the engineer can build on, a water supply, and a wastewater disposal route.
Run all five checks before you sign contracts. €1,500–€4,000 on a site assessment saves €30k–€80k in later surprises.
Planning and wastewater are the two deal-killers. Soil and access can usually be engineered; planning and wastewater can be hard refusals.
When this matters most
You're choosing sites, you've gone sale-agreed, or you've inherited land and don't know if it's buildable.
When this doesn't apply
You already own a buildable site with full planning permission, tests done, and an engineer appointed.
Frequently asked questions
How do I know if a site is buildable in Ireland?
Run five checks: planning status with the county council, road access (entrance and sightlines), ground conditions (soil test, foundation class), water supply (mains or well with yield test), and wastewater (mains or treatment system with percolation test).
What kills a site for building in Ireland?
Planning refusal (rural housing policy, ribbon development, flood risk) and wastewater failure (percolation test too slow, EPA setback not met). Soil and access can usually be engineered; planning and wastewater can be hard refusals.
How much does a site assessment cost?
€1,500–€4,000 for a soil test, percolation test, and water yield test. Add €300–€600 for an engineer's desktop feasibility study on top.
Sources
EPA, Code of Practice: Domestic Wasteholding Treatment Systems (2018, updated 2021). https://www.epa.ie/publications/compliance--enforcement/waste-water/
Geological Survey Ireland, Irish Soil Classification System. https://www.gsi.ie/
Frequently asked questions
How do I know if a site is buildable in Ireland?
Run five checks: planning status with the county council, road access (entrance and sightlines), ground conditions (soil test, foundation class), water supply (mains or well with yield test), and wastewater (mains or treatment system with percolation test).
What kills a site for building in Ireland?
Planning refusal (rural housing policy, ribbon development, flood risk) and wastewater failure (percolation test too slow, EPA setback not met). Soil and access can usually be engineered; planning and wastewater can be hard refusals.
How much does a site assessment cost?
€1,500–€4,000 for a soil test, percolation test, and water yield test. Add €300–€600 for an engineer's desktop feasibility study on top.
When this matters most
You're choosing sites, you've gone sale-agreed, or you've inherited land and don't know if it's buildable.
When this doesn't apply
You already own a buildable site with full planning permission, tests done, and an engineer appointed.
Where to go next
Next decision
The next step in your build sequence.