Extension Cost Calculator Ireland

Extension Cost Calculator Ireland

Planning a home extension in Ireland? Whether you’re adding extra living space, extending your kitchen, or converting a garage, knowing the true cost of a house extension is one of the most important steps before starting construction.

Our Extension Cost Calculator Ireland helps you estimate the average cost of building an extension in Ireland based on size, type, finish quality, and optional extras. It’s fast, free, and designed specifically for Irish homeowners.

👉 For more property and building cost tools, explore our home and finance calculators across CalcIreland.

What Is an Extension Cost Calculator?

An Extension Cost Calculator is an online tool that estimates how much it may cost to build a house extension in Ireland. By entering key details such as the extension size (in square metres), type of extension, and level of finish, you can get an instant estimated cost in euros.

Unlike generic calculators, this calculator is built using Ireland-specific construction cost ranges, making it more accurate for local planning, budgeting, and decision-making.

This tool is ideal for:

• Homeowners planning an extension

• First-time renovators

• Property investors

• Anyone budgeting for home improvement in Ireland
  
  You can also go through - Window Cost Calculator Ireland

How to Use the Extension Cost Calculator Ireland

Using the calculator is simple and takes less than a minute:

1. Enter the extension size
   Input the total floor area of your planned extension in square metres.

2. Select the extension type
   Choose from single-storey, double-storey, or garage conversion options.

3. Choose the finish quality
   Select standard, mid-range, or high-end finishes depending on your budget.

4. Add optional extras
   Include kitchen installation, bathroom costs, or professional fees if required.

5. Click “Calculate Cost”
   Instantly see your estimated extension cost in Ireland.

   

How Does the Extension Cost Calculator Work?

The calculator uses average Irish construction costs per square metre and adjusts the total based on your selected options.

Here’s how the calculation works behind the scenes:

• Base cost per sqm is applied depending on extension type

• Finish quality multiplier adjusts the cost for materials and fittings

• Fixed-cost extras are added for kitchens and bathrooms

• Professional fees (architect and planning) are calculated as a percentage

The result is a realistic estimated extension cost that reflects current building trends in Ireland.

Please note: This is an estimate only. Final costs may vary depending on location, contractor rates, planning permission, and material prices.

Why Use Our Extension Cost Calculator?

There are many reasons why homeowners across Ireland use our calculator:

✅ Ireland-Specific Estimates

Built using construction cost data relevant to Ireland — not generic global averages.

✅ Quick & Easy

No sign-ups, no waiting — get instant results online.

✅ Better Budget Planning

Helps you understand whether your extension plans fit your budget before contacting builders.

✅ Transparent Cost Breakdown

Clearly shows how size, finish, and extras affect the final cost.

✅ Free to Use

Completely free with no hidden charges.

Average Extension Costs in Ireland

While prices vary, here are typical extension costs in Ireland:

• Single-storey extension: €2,000 – €2,500 per sqm

• Double-storey extension: €2,300 – €3,000 per sqm

• Garage conversion: €1,500 – €2,600 per sqm

High-end finishes, complex designs, or city locations like Dublin may increase costs.

Factors That Affect Extension Costs in Ireland

Several factors influence the final cost of a house extension:

• Size of the extension

• Type (single vs double storey)

• Quality of materials and finishes

• Kitchen or bathroom installation

• Architect, engineer, and planning fees

• Location within Ireland

• Labour and material price fluctuations

Our calculator helps account for many of these variables to give you a clearer estimate.

Frequently Asked Questions (FAQ)

How much does a house extension cost in Ireland?

The cost of a house extension in Ireland typically ranges from €2,000 to €3,000 per square metre, depending on the type of extension and finish quality.

Is this extension cost calculator accurate?

The calculator provides a realistic estimate based on average Irish construction costs. However, actual prices may vary depending on builder quotes, location, and project complexity.

Does the calculator include VAT?

This calculator provides an estimated construction cost. VAT treatment may vary depending on contractors and services, so it’s best to confirm VAT details with your builder.

Can I use this calculator for planning permission?

Yes, the estimate can help with early-stage budgeting and planning, but it should not replace professional cost assessments for planning applications.

Does it include architect and planning fees?

You can optionally include architect and planning fees, calculated as a percentage of the total estimated cost.