External Wall Insulation in Dublin 15

For a standard 3-bedroom semi-detached home in Dublin 15 (such as in Blanchardstown, Castleknock, or Clonsilla), external wall insulation costs between €13,000 and €19,000 gross. As an SEAI Registered Contractor (#10423), Isotherm deducts the €6,000 SEAI grant directly from your invoice, leaving a net out-of-pocket investment of €7,000 to €13,000. Detached family homes range from €18,000 to €26,000 gross (net €10,000 to €18,000 after the €8,000 grant), while mid-terrace properties cost €10,500 to €14,000 gross (net €7,000 to €10,500 after the €3,500 grant), and apartments receive a €3,000 grant.

For the vast majority of suburban houses across Dublin 15 (including Blanchardstown, Clonsilla, Ongar, Huntstown, Hartstown, and Tyrellstown), external wall insulation is classified as Exempted Development under Section 4(1)(h) of the Planning and Development Act 2000, provided the external finish matches the character of the neighbourhood. However, if your property is a Protected Structure or situated within an Architectural Conservation Area (ACA)—such as parts of historic Castleknock Village or period properties along the Strawberry Beds—consultation with Fingal County Council is required. We evaluate planning and boundary clearances during your initial site survey.

Our central operations depot and metal fabrication workshop are located at Unit 20, Westlink Industrial Estate, Kylemore Road, Inchicore, Dublin 10. Via the M50 Northbound, N3 Navan Road corridor, or Chapelizod bypass, our direct installation crews and project supervisors reach Dublin 15 (Castleknock, Blanchardstown, Clonsilla, Ongar) in just 15 to 20 minutes. This close proximity ensures daily on-site supervision, tight quality control, and immediate material replenishment.

We specify NSAI Agrément certified Baumit external wall insulation systems featuring high-density graphite EPS (Grey EPS with thermal conductivity λ = 0.031 W/mK) and vapour-permeable Baumit SilikonTop or NanoporTop self-cleaning silicone topcoats. Dublin 15 homes built in the 1970s–2000s face open wind exposure from the Dublin/Meath plains. Baumit silicone render actively repels driving rain, allows trapped moisture in solid masonry to breathe outwards, and resists micro-cracking and green algae growth for decades without repainting.

Adding 100mm to 150mm of external insulation extends beyond your existing concrete or uPVC window sills. Rather than fitting cheap plastic clip-ons, our sister company Cills.ie custom fabricates heavy-gauge, powder-coated aluminium window sills in our Inchicore workshop. Each sill features welded watertight upstands, integrated thermal drip edges, and is powder-coated in any RAL colour (such as RAL 7016 Anthracite Grey or RAL 9016 White) to match your existing window frames perfectly.

Yes, 100%. Because all work—scaffolding, EPS adhesive fixing, mechanical dowel anchoring, mesh basecoat application, sill fitting, and silicone render texturing—is carried out on the exterior building envelope, there is zero internal dust, no loss of interior floor space, and zero disruption to your daily living routine inside the home.

To qualify for the SEAI Better Energy Homes grant in Dublin 15, your home must have been built and occupied on or before 31 December 2010 (verified by ESB MPRN meter registration). Additionally, under the updated SEAI second wall measure rules introduced in March 2026, homes that previously received a cavity wall bead grant are now fully eligible to claim the full €6,000 to €8,000 external wall insulation grant to reach modern A-rated energy efficiency.