Leading Home Extension Specialists in Sydney’s North
Create more space with seamless transitions between new and existing areas . Thoughtfully designed extensions that suit the changing needs of growing families across the Northern Beaches and North Shore.
Space to grow without the stress of moving
A home extension can be the perfect way to stay in the neighbourhood you love, without compromising on space or lifestyle.
At JTB Building, we’ve helped families across Sydney’s North upgrade their homes with well-planned, beautifully built additions that feel like they’ve always been there.
We’ve completed countless ground floor extensions, upper storey additions, and open-plan upgrades in suburbs like Avalon, Collaroy, Dee Why, Mosman and Turramurra. Our team understands the local landscape - from sloping blocks and bushfire zones to tight access sites and heritage listed homes.
Types of Extensions
Tailored solutions for every home
Ground Floor Extensions
Add bedrooms, living space or a home office with functional layouts that flow with the existing home.
Second Storey Additions
Build up to gain extra space, better views and more separation for growing families.
Open Plan Living Upgrades
Create light-filled spaces designed for modern family life and indoor-outdoor flow.
No surprises. just smart, transparent building
Manly
Fixed Pricing & Timelines
We offer fixed-price contracts and realistic timelines, so you know exactly what to expect from the start. Every extension begins with a clear scope, mapped-out milestones, and open communication.
Throughout your build, we keep you updated well in advance with progress and next steps allowing you feel confident and comfortable at every stage.
Why Northern Sydney Homeowners Choose
JTB Building
Experience
20+ years building high-end homes with a reputation for quality and service experience.
Clear Communication
You’ll always know where things stand, with regular updates and honest advice.
Client-Focused
We listen, guide, and collaborate ensuring a smooth, stress-free experience. From first day on site to final handover, we’re with you every step of the way.
Local Knowledge
Deeply connected to the Northern Beaches and North Shore community.
Transparent Pricing
Our quotes are detailed, accurate, and backed by solid planning.
Building With JTB
Home Extension FAQs
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No. If you already have an architect or designer we’ll collaborate with them to establish project goals. If you’re starting from scratch, we can introduce you to trusted architects and interior designers and help manage the process from early concept through to completion.
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Costs vary depending on the size, scope, and finish of your project. For more accurate figures, we offer a planning and budgeting service that outlines estimated costs before investing in the various stages of design development with the major stages being concept designs, pre Development Application design documentation and finally Construction Certificate documentation.
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Most renovations take between 6 and 14 months depending on the design, site, and extent of ground works. We’ll give you a detailed timeline before the build begins.
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It depends on the scale of the works. For most of the projects we undertake, we usually recommend relocating in order to keep things safe and efficient. We’ll discuss this with you in the planning phase.
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Most extensions will require approval through either a Development Application (DA) or Complying Development (CDC).
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Yes. We regularly complete upper-level additions and know how to work with your home’s structure to get the best result.
Let’s talk about your Extension
Give us a call or send us an enquiry. We’ll run you through the process, answer your questions, and keep things clear from day one.
License Number #194684C