Home extension is a lucrative option for people who want a bigger space without moving home. However, when it comes to the cost of home extension, the breakdown is not as simple as you think. There are many factors that play a key role in determining the overall cost for a house extension, such as area, cost of materials, complexity of design, etc.
In this article, we’ll discuss how much does it costs for a house extension depending upon the scale and type of addition.
How Much Does It Cost To Extend A House?
There are different cost ranges for house extensions, with basic to mid-range house extensions costing anywhere between $1,500 to $4,000 per square meter. A high-end or complex house extension cost between $4,000 to $5,500 per square meter. These cost estimates include materials, labour, and builder margins while excluding the planning permits, design fee, and some hidden costs which we’ll discuss further.
| Extension Type | Cost Range (Per Square Meter) | Includes | Excludes |
|---|---|---|---|
| Basic to Mid-Range | $1,500 – $4,000 | Materials, Labour, Builder Margins | Planning Permits, Design Fees, Hidden Costs |
| High-End / Complex | $4,000 – $5,500 | Materials, Labour, Builder Margins | Planning Permits, Design Fees, Hidden Costs |
What are the Factors that influence the cost of house extension?
Location
Top-tier cities have higher material and labour costs, making house extensions in them more expensive than elsewhere. However, the cost of a house extension in Brisbane is comparatively cost-effective despite it being one of the top tier cities.
Size and Scope of Construction
As the cost of extension is estimated per square meter, the size and scope of construction matters. The larger the project, the greater the price. However, the size of the home extension isn’t the only decisive factor when it comes to cost estimation. At times, smaller home extensions may end up costing more than the larger ones owing to other factors which we’ll discuss further.
Construction Complexity
Custom house extensions with complex designs and complicated structural changes will cost more than a standard house extension irrespective of the size. The cost piles up with the use of special materials in construction.
Site Conditions
Your existing house needs a new foundation to support the added weight of a home extension and to maintain its structural integrity. In this situation, the bearing capacity of the soil matters. If the soil is shifting or unstable, sophisticated engineering helps access the deeper parts of the earth, which adds to the overall cost of the house extension.
Design and Finish
Custom high-end finishes cost more than standard ones. For a home extension to blend in with the current home, it’s sometimes necessary to use luxury materials, fittings, fixtures, etc. which will take the home extension cost up a notch.
Approvals
Home extensions need council approval along with other non-negotiables such as site surveys, heritage overlays, ecological zone compliance, etc., which cost money as well as time.
Types of Home Extensions and Their Cost
Single-Storey House Extension
Single-Storey house extension refers to the addition of rooms horizontally to an existing property without any vertical construction. It’s an ideal option to utilise a large block of land. Single-storey home extension cost ranges from $1,500 per square meter to more than $4,000 per square meter without additional costs.
Double-Storey House Extension
Double-storey extensions are vertical additions to a home like a second storey or additional rooms. The cost of adding a second storey is high as it requires extensive structural work including foundation reinforcement. Residents may have to relocate for the duration of the project which adds to the cost. The average double-storey house extension cost comes from around $3,000 to $5,000 per square meter.
Rear or Side Extension
When people want to add an extra kitchen, dining area, or living area, they go for rear or Side extensions. On average, rear or side home extensions cost between $2,000 to $4,000 per square meter.
Granny Flat Extensions
Clients consider a granny flat construction for passive rental income or for family care purposes. A granny flat is a second dwelling within the same property that typically accommodates one or two people. These self-contained accommodations may cost between $150,000 to $300,000 to construct.
What Are The Hidden Costs Of House Extensions?
Apart from the cost of materials, labour, builder margins, and engineering costs, there are additional costs associated with house extensions, such as:
- Utilities and service costs like plumbing, electrical works, sewer relocation or upgrades, etc.
- Internal finishes like flooring, cabinetry, fixtures, and fittings.
- Site prep and clean-up costs include tree removals, asbestos handling, waste disposal, etc.
- Temporary accommodation costs in case of invasive house extension that requires you to move out.
If you’re experiencing a lack of useful space and purchasing a new home is not an option for you, then adding an addition to a house is your best bet. You retain your precious home while making it spacious and future ready. In the hands of an experienced builder, your home extension project will be a lucrative investment that not only provides you with extra space but also enhances property value. To get a free consultation for house extension in Brisbane, give Innovare Builders a call and we’ll walk you through the entire process.
