How accurate is this calculator?

This calculator provides a ballpark estimate based on average costs per square metre in Ireland. It's an excellent tool for initial budgeting. However, the final cost will depend on specific factors like your home's condition, your location, the specific insulation system chosen, and the installer's rates. For a precise figure, you must get a detailed quote from a certified installer.

What is included in the estimated price?

The estimate generally covers the main components of an EWI project: supply of insulation materials, labour, scaffolding, a standard render finish, and VAT. It typically does not include the cost of additional works like moving pipes, extensive wall repairs, or replacing window sills, which is highly recommended.

How do I get an exact quote for my home?

The best way is to have a certified SEAI installer visit your property. They will measure the exact wall area, assess the condition of your walls, discuss finish options, and provide a firm, detailed quotation. You can browse our installer directory to connect with vetted professionals in your area.

Does this calculator apply to the UK?

This calculator is based on Irish costs (in Euros) and SEAI grants. While the principles of EWI are the same in the UK, material and labour costs may differ, and different grant schemes apply (e.g., the Great British Insulation Scheme). We recommend checking with UK-based installers for accurate pricing.

Isotherm - Insulation & ICF Authority in Ireland & UK

Thinking about upgrading your home with external wall insulation (EWI)? Our easy-to-use calculator gives you a realistic estimate of the cost in Ireland, factoring in the valuable SEAI grants.

This tool is designed to help you budget effectively for what is one of the most impactful energy upgrades you can make to your home. Simply enter your house type and the approximate external wall area to get started. If you're unsure of your wall area, a typical 3-bed semi-detached house is around 120m².

Why Calculate Your EWI Cost?

Budget with Confidence: Get a clear idea of the investment required.
Understand the Grants: See exactly how the SEAI grant reduces your final cost.
Make an Informed Decision: Compare the cost against the long-term benefits of energy savings and increased comfort.

For a complete breakdown of what's involved, read our full guide to EWI costs in Ireland.

EWI Cost Calculator Ireland

Why Calculate Your EWI Cost?

Frequently Asked Questions