How Much Does a Double-Storey Extension Cost in Ireland? Your In-Depth Guide

Farnan Culkin
May 29, 2023

Considering a double-storey extension for your home but not quite sure about the cost involved? Fear not! At BuildPro, we know that the double-storey extension cost can sometimes seem like a mysterious puzzle. That's why we've put together this comprehensive guide to help you navigate through every step of the process in Ireland.

What is a Double-Storey Extension?

A double-storey extension is a home addition that adds space to your property's ground and first floors. This renovation can significantly increase your living space without moving to a bigger house. However, understanding the costs involved in building a double-storey extension is essential before you decide to proceed with your project.

Why Choose a Double-Storey Extension?

Enhanced Space

A  double-storey extension can significantly increase the size of your home, providing ample space for additional bedrooms, bathrooms, living areas, or even a trendy home office.

Increased Property Value

Property experts estimate that a double-storey extension could boost your home's value by up to 20%, making it a smart long-term investment.

More Design Possibilities

Whether you want to harmonise with your home's architecture or create a strikingly modern contrast, a  double-storey extension offers unlimited design options.

Greater Light and Energy Efficiency

Opting for a design with large windows or skylights will flood your home with natural light. Moreover, a well-designed extension can enhance your home's energy efficiency, saving on heating and cooling costs.

Factors Influencing the Double-Storey Extension Cost

When planning for a double-storey extension, it's important to understand that costs can vary greatly depending on various factors.

Size and Design

The size and complexity of your extension will heavily impact the cost. A larger, more complex design will require more materials and labour, leading to higher costs.

Material Quality

The quality and type of materials used can affect the overall cost. High-quality materials usually have a higher price tag, but they might offer better longevity and aesthetic appeal.


Your geographical location within Ireland also affects the double-storey extension cost. The cost of labour and materials can vary regionally.

Planning Permission

You may need to acquire planning permission for your extension, and the cost of this process can add to your overall expenditure.

Additional Features

Additional features such as advanced heating systems, special windows, or luxury finishes can increase the cost.

Average Double-Storey Extension Cost in Ireland

While it's difficult to provide a one-size-fits-all figure, you can typically expect the cost of a double-storey extension in Ireland to range from €1,500 to €2,500 per square meter, depending on the factors mentioned earlier. However, remember that these figures are approximate, and the actual cost can differ significantly based on your specific project requirements.

Cost Breakdown

Let's look at a rough cost breakdown for a standard 20 square meter double-storey extension:

  • Building work: €40,000 - €50,000
  • Windows and doors: €5,000 - €10,000
  • Roofing: €4,000 - €8,000
  • Interior finishes: €10,000 - €15,000
  • Professional fees (architect, planning permission, etc.): €5,000 - €10,000

This brings the total to around €64,000 - €93,000 for a standard double-storey extension, excluding any luxury additions or unique design features.

Tips for Reducing the Double-Storey Extension Cost

While the costs can seem high, there are ways to manage and reduce your double-storey extension cost.

Set a Budget

A well-defined budget can help you control costs from the start. It can guide your choices concerning design, materials, and builders.

Choose a Simple Design

Choosing a simple design can help reduce costs. Complex designs usually require more time, labour, and materials, which can inflate your budget.

Compare Quotes

Obtain quotes from different builders to ensure you are getting a competitive price. Be sure to compare the services included in each quote, not just the total cost.

How BuildPro Can Help?

Expert Consultation

At BuildPro, our experts offer insightful advice on design, planning permissions, contractor selection, and ensuring your project stays on track and within budget.

Understanding Costs

We appreciate the financial implications of such a significant investment. Our team provides transparent cost breakdowns, aiding in effective budget management.

Customised Solutions

BuildPro recognises the uniqueness of every home and homeowner. We deliver tailored solutions that align with your vision and requirements for your extension project.

Contractor Selection

Finding trustworthy professionals can be challenging. BuildPro alleviates this pressure with a platform connecting homeowners to reputable contractors specialising in double-storey extensions.

Quality and Security

With BuildPro, quality and security are paramount. You’ll benefit from our quality guarantee and secure payment system, ensuring peace of mind during your home transformation journey.

Ready to Expand Your Home?

If you're ready to explore the possibilities of a double-storey extension for your home, BuildPro is here to assist. With our extensive experience and understanding of the double-storey extension cost, we can help you take the first steps towards your dream home. Contact us today to schedule a consultation and start your home extension journey with confidence.

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Frequently Asked Questions

How much does a 2-storey extension cost in Ireland?

The cost of a two-storey extension in Ireland can vary greatly depending on the size, design, materials, and location. On average, you might expect to pay around €1,800 per square metre. However, this can range from €1,500 to €2,500 per square metre, depending on the project's specifics.

How long does a 2-storey extension take to build?

The time it takes to build a two-storey extension can depend on several factors, including the project's size and complexity, the contractors' speed, and weather conditions. On average, you can expect a two-storey extension to take around 14 to 16 weeks to complete.

Do you need planning permission for a 2-storey extension?

Yes, in most cases, you will need planning permission for a two-storey extension in Ireland. There are some exceptions, but it's best to consult with a professional or local council to ensure you comply with all planning regulations.

How deep do foundations need to be for a double-storey extension?

The foundations usually need to be at least 200mm deep for a double-storey extension. However, the exact depth can vary depending on the ground conditions and the weight of the building. A structural engineer can provide a more precise specification based on a detailed survey of your property.

What are the rules for double-storey extensions?

Double-storey extensions are subject to several rules and regulations in Ireland. These include regulations about the extension's size, height, location on the property, and impact on neighbours. Planning permission is typically required, and the extension must comply with building regulations to ensure safety and quality standards. We recommend consulting with an expert from BuildPro for accurate and detailed information.

Can a double-storey extension increase property value?

Yes, a double-storey extension can significantly increase your property's value. Property experts estimate that such an extension could boost your home's value by up to 20%. This makes it not only a means to enhance living space but also a smart long-term investment. However, the exact value increase can vary based on the quality of the extension and the property's location.

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*FYI, parts of this blog post were drafted by artificial technlogy. But rest assured, it's been thoroughly researched, edited, reviewed and me & my team.
Farnan Culkin

Farnan Culkin is a seasoned expert in the home improvement industry and the proud founder of BuildPro. His passion for home renovation and home extensions has led him to create a platform that educates homeowners, helping them transform their Irish homes into their dream dwellings.