Ridge Ventilation in Ireland — Why It Matters, What It Costs, and the Building Regs
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Ridge ventilation: €20–€40/m linear. Required for cold attic and warm roof. Prevents condensation and timber rot.
Ridge ventilation in Ireland: €20–€40/m linear. Required for cold attic and warm roof builds. Purpose: remove moisture from the roof space (from cooking, breathing, and bathing in the rooms below). Prevents condensation, timber rot, and insulation degradation. Building Regulations 2023 TGD-F (Ventilation) requires ventilation to all roof spaces. Equivalent cross-section: 1/300 of the ceiling area for a cold attic (e.g. 100 m² ceiling = 0.33 m² ventilation, split between ridge and eaves). Ridge vents (continuous or discrete) at the ridge; soffit vents at the eaves. Most Irish self-builds use continuous ridge vent strip plus discrete soffit vents, both pre-finished to match the roof.
TL;DR
Ridge ventilation in Ireland: €20–€40/m linear. Required for cold attic and warm roof builds.
Purpose: remove moisture from the roof space. Prevents condensation, timber rot, and insulation degradation.
Building Regulations 2023 TGD-F (Ventilation) requires ventilation to all roof spaces. Equivalent cross-section: 1/300 of the ceiling area for a cold attic.
When this matters most
You're at design stage and need to detail the roof ventilation.
When this doesn't apply
The roof is on and the ventilation is in place.
Frequently asked questions
How much does ridge ventilation cost in Ireland?
€20–€40/m linear installed. For a 10 m ridge: €200–€400. Plus soffit vents at the eaves, similar cost.
Why is ridge ventilation required?
Building Regulations 2023 TGD-F. Removes moisture from the roof space. Prevents condensation, timber rot, and insulation degradation. Required for cold attic and warm roof builds.
What is the equivalent ventilation area?
1/300 of the ceiling area for a cold attic. For a 100 m² ceiling: 0.33 m² total, split between ridge and eaves.
Sources
Building Regulations 2023, TGD-F (Ventilation). https://www.gov.ie/
Frequently asked questions
How much does ridge ventilation cost in Ireland?
€20–€40/m linear installed. For a 10 m ridge: €200–€400. Plus soffit vents at the eaves, similar cost.
Why is ridge ventilation required?
Building Regulations 2023 TGD-F. Removes moisture from the roof space. Prevents condensation, timber rot, and insulation degradation. Required for cold attic and warm roof builds.
What is the equivalent ventilation area?
1/300 of the ceiling area for a cold attic. For a 100 m² ceiling: 0.33 m² total, split between ridge and eaves.
When this matters most
You're at design stage and need to detail the roof ventilation.
When this doesn't apply
The roof is on and the ventilation is in place.
Where to go next
Next decision
The next step in your build sequence.