Granny Flats Cost Ireland

by | Apr 21, 2024


Are you considering building a granny flat in Ireland and looking to figure out the cost?

In this blog, we’ll explain into detail the average cost of granny flats in Ireland. From understanding the factors that influence costs to exploring ways to minimise expenses, we’ll discuss everything.

We’ll discuss average cost ranges across different regions, discuss hidden expenses you might not have considered, and offer practical tips to help you make the most of your budget.
So, let’s get into it!

What Exactly Are Granny Flats, and Why Are They Gaining Popularity in Ireland?

Granny flats, also known as accessory dwelling units or ADUs, are self-contained living spaces typically built on the same property as a primary residence. They offer additional living space that can be used for various purposes such as accommodating ageing parents, providing rental income, or creating a home office or studio.


In recent years, granny flats have gained significant popularity in Ireland due to changing demographics and housing needs. With an ageing population and increasing housing costs, granny flats provide a practical solution for homeowners to maximise the use of their property and address housing shortages.

What is the Significance Behind Understanding Costs of Granny flats?

The significance of understanding the costs of building a granny flat is important for homeowners considering this investment. By having a clear understanding of the expenses involved, homeowners can better plan their budget, avoid unexpected financial burdens, and make clear decisions throughout the construction process. 

Moreover, complete understanding of  the costs allows homeowners to prioritise features according to their budgetary constraints, ensuring that the final product meets their needs without overspending. 

Additionally, being aware of the financial implications enables homeowners to explore potential financing options and seek out cost-saving measures, maximising the value of their investment in the long run.

What Factors Influence the Cost of Granny Flats?

Here are some factors which influence on cost:


The location of the granny flat plays a significant role in determining its cost. Urban areas typically have higher land and construction costs compared to rural areas. 

Additionally, factors such as easy access to facilities, transportation hubs, and desirable neighbourhoods can impact overall expenses.

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Size and Design

The size and design of the granny flat directly affect its construction costs. Larger units with complex designs require more materials and labour, resulting in higher expenses. Homeowners should carefully consider their space requirements and design preferences to balance functionality with budget constraints.

Materials Used

The choice of materials used in construction significantly influences the cost of building a granny flat. High-quality materials may come with a higher upfront cost but can offer long-term durability and energy efficiency, potentially reducing maintenance and operating expenses over time.

Construction Regulations and Permissions

Following construction regulations and obtaining necessary permissions can add to the overall cost of building a granny flat. Compliance with building codes, zoning regulations, and obtaining permits from local authorities are essential steps in the construction process that may require additional time and resources.

Facilities and Additional Features

Adding facilities and additional features into the granny flat design can increase construction costs. Features such as upgraded appliances, custom finishes, and specialised technology add value but also come with a higher price tag. Homeowners should prioritise their needs and budget accordingly when selecting features.

How Much Does Granny Flats Cost in Ireland?

In Ireland, the average cost of building a granny flat ranges from €70,000 to €145,000. However, factors such as location, size, and features influence the overall expense. Here are some estimated price ranges provided to understand better about granny flats cost:

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A. Land Preparation and Site Work

Cost Range: €3,000 – €10,000

Includes excavation, levelling, and utility connections.

Preparing the land and site for building involves tasks like clearing, grading, and preparing utilities such as water, electricity, and sewage connections.

B. Construction Costs

Cost Range: €50,000 – €100,000

Covers materials, labour, and construction of the granny flat structure.

Construction costs include everything from foundation and framing to roofing, siding, and interior finishing, as well as labour costs associated with these tasks.

C. Utilities and Infrastructure

Cost Range: €5,000 – €10,000

Involves electrical, plumbing, and HVAC installation.

This includes the installation of essential systems such as electrical wiring, plumbing pipes, and heating, ventilation, and air conditioning (HVAC) systems to ensure the granny flat is fully functional.

D. Permits and Legal Fees

Cost Range: €1,000 – €5,000

Includes permits, inspections, and legal documentation.

Obtaining permits, conducting inspections, and handling legal paperwork are necessary steps in compliance with regulations and ensuring the granny flat meets all legal requirements.

E. Furnishing and Interior Design

Cost Range: €5,000 – €20,000

Includes furniture, appliances, and interior finishes.

Furnishing and interior design costs include everything from purchasing furniture and appliances to selecting finishes such as flooring, cabinetry, countertops, and lighting fixtures.

What is the Average Cost Difference of Granny Flats Between Urban and Rural Areas?

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To understand the difference between average cost of granny flats in the urban and rural areas, consider the following comparison:

Urban vs. Rural Areas

Urban areas have higher costs, averaging €90,000 to €160,000, due to higher land and construction expenses. In contrast, rural areas offer more affordable options, with costs ranging from €50,000 to €120,000, depending on local factors.


Figuring out the costs for building granny flats in Ireland is really important. From location to design preferences, each element contributes to the overall expense. Including land preparation for interior design, various factors influence expenses. 

Urban areas generally consume higher costs compared to rural regions. Despite these variations, the average cost ranges from €70,000 to €145,000 nationwide. To start building your granny flat, contact Coastal Homes. Our expertise ensures cost-effective solutions customised to your needs.


1. How much do granny flats cost in Ireland?

The cost of building a granny flat in Ireland depends on factors like design, size and materials used; the average price can vary significantly.

2. Are there affordable options for building a granny flat?

Yes, there are cheaper alternatives such as log cabin granny flats which offer small living spaces at more affordable prices while maximising space on your property.

3. Can you rent out a granny flat in Ireland?

Renting out your newly built granny flat is possible once regulations and planning permission requirements set by government bodies are met; this could provide an extra income source while offering decent lodgings to tenants in Ireland.

4. What government assistance is available for constructing granny flats?

Some grants assist with construction costs of these additional home units exist under the Irish Government schemes, but terms and conditions apply so it’s advisable to research thoroughly before proceeding with any plans.

5. Who will handle the construction of my Granny Flat in Ireland?

Coastal Homes specialise in constructing high-standard concrete small homes or bedroom flats following approved designs within established budget limits; reaching out to us would ensure faster project completion targeting superb quality standards.

6. How long does it take to build a granny flat?

The time it takes to build a granny flat can vary depending on the size and complexity of the project. Typically, it takes four to six weeks to build a flat, depending on the size and features of the granny flat.

Building your dream home?

Trust Coastal Homes to make it a reality! Our experienced team of professionals is dedicated to providing top-quality construction services that meet your unique needs. Contact us today to learn more about our services.