Home Extensions

Covered alfresco and outdoor living area flowing to a pool, the indoor outdoor connection a Sydney home extension creates

Home Extensions · Sydney

Home extensions in Sydney, done properly.

Rear and side extensions across Sydney by a licensed builder. Most extensions run $70,000 to $300,000 depending on size and how much of the existing structure has to change, itemised quote, honest programme, one builder from concept to handover.

★★★★★Rated 5.0 by our clients on Google
NSW Builder’s Licence 487370CItemised quotesClear inclusions & exclusionsSydney wide

Start here

Tell us about your home.

No sales pitch, no obligation. Here is exactly what happens when you enquire:

  • 1Answer a few quick questions. One at a time, takes about two minutes, so the first conversation is about your project rather than the basics.
  • 2We call you within 24 to 48 business hours. A builder, not a salesperson. Then we walk your home and yard with you on site.
  • 3You receive a written, itemised estimate. Real numbers for your home. If the project does not stack up, we tell you that too.

From our clients

Rated 5.0 on Google.

★★★★★

“We had Strava Group complete major renovation works on our property and were blown away with the quality. The attention to detail and overall finish were amazing.”

Aloona T.
Google review
★★★★★

“Great communication, honest work, easy to work with, highly recommend to work with for any new build/renovations. If you are looking to get work done without worrying about shortcuts Strava Group is builder to use.”

Orom Gabriel
Google review
★★★★★

“I highly recommend Strava Group to everyone great workmanship, reliable service, and I couldn’t be happier with the result.”

Jonathan
Google review

Extending out, not up

More space, on the ground you already own.

Strava Group builds home extensions across Sydney: rear additions, side extensions and whole-of-back transformations that open the house to the yard. Extending out suits homes with land to spare, and it is usually the fastest way to get a bigger kitchen, open plan living and a real connection to outside.

We regularly deliver:

  • Rear extensions and additions
  • Side extensions on wider blocks
  • Open plan kitchen, dining and living
  • Alfresco and indoor-outdoor connections
  • New master suites and family rooms
  • Laundries, mudrooms and storage done properly
  • Structural openings between old and new
  • Exterior upgrades to tie old and new together

Thinking about going up instead? That is a different build with different engineering, and we do that too: see second storey additions.

The best extensions do not just add a room. They fix the whole back of the house: where the kitchen sits, how the living opens to the yard, and where the light comes from all day.

The Strava standard

How we build differently.

An extension lives or dies at the junction between old and new. We build for longevity, and on every extension we run:

Every new-to-existing junction properly detailed

This is where most extensions crack, leak and part company with the house. It is almost always a detailing shortcut, not settlement. Ours get a proper structural tie, flashing and movement detail.

The existing structure gets rectified, not covered

Where the extension meets the house, we screw off and re-brace the adjoining structure, tying new and old together so the whole building moves as one and future cracking is designed out, not painted over.

Footings matched to the ground, not the minimum

New footings are engineered for your soil and detailed against the existing ones, because differential movement between old and new slabs is the classic extension failure.

Furring channels for a dead flat finish

Where new ceilings and walls run through to existing rooms, furring channels give one level plane across both, so you cannot see where the house ends and the extension begins.

Waterproofing is a documented hold point

New wet areas are inspected and photographed before a single tile goes on, to AS 3740, and new roof-to-old-roof junctions get the same treatment.

Everything photographed before it is covered

You receive the record at handover, so in ten years you know exactly what is behind your walls and under your floor.

Before starting Strava Group, I spent seven years on the tools as a carpenter and five years running sites. The failures I kept seeing in extensions were always at the join: cracked cornices along the old wall line, roofs that leaked where new met old, floors that stepped as slabs settled differently. None of it was illegal. All of it was avoidable. None of this shows up in a finished-room photo. All of it shows up in year seven.

Honest numbers

What a home extension actually costs in Sydney.

Most builders will not put numbers on a website. We will, because the alternative is wasting your time and ours across three meetings before anyone mentions a figure.

Home extension, depending on size and scope$70k–$300k
Ground floor extension work$2,500–$4,500 /m²
Preliminaries, on top of build costapprox. $30,000

Preliminaries are the costs that exist before a single wall moves: site fencing, temporary services, waste removal, insurances, engineering and supervision. They are real, they are unavoidable, and a quote that does not show them separately has either buried them or forgotten them.

The band is wide because extensions are wide: a modest rear addition sits at one end, a full-width open plan transformation with structural openings back into the house sits at the other. How much of the existing structure has to change is usually the largest single factor, followed by wet areas and site access.

Every project is quoted properly after a site inspection. These ranges are here so you can decide whether it is worth a conversation.

Stay or go

Cheaper than moving, better than settling.

Once you account for stamp duty, agent commission, legal fees and moving costs, changing suburbs in Sydney frequently costs more than the extension that would have solved the problem, and you keep the street, the neighbours and the school catchment you already have.

An extension can also be staged alongside a full renovation of the existing rooms, you pay the preliminaries once and open the walls once. And if the block will not carry an extension, we tell you before you spend money on design, and talk honestly about whether going up is the better path for your home.

Same address. Same street. A home that finally has room for the way you live.

Service areas

Home extensions across Sydney.

We build extensions across 46 Sydney suburbs, concentrated in the north west, the Hornsby shire, the Ryde district, the inner west and St George. Select your suburb for local council information, the property types we see there and what extensions in that area typically cost.

Looking for a different service in one of these suburbs? We also build second storey additions and complete home renovations across the same areas. Not listed? We cover most of the Sydney metropolitan area. Get in touch and we will tell you honestly whether your location works for us.

Good to know

Home extension questions.

How much does a home extension cost in Sydney?
Most home extensions run $70,000 to $300,000 depending on size and how much of the existing structure has to change, at roughly $2,500 to $4,500 per square metre for ground floor work, with around $30,000 in preliminaries on top. Structural openings back into the house, wet areas and site access move the figure most.
Do I need council approval for a home extension?
Usually yes, but often not a full DA. Many Sydney extensions qualify for a Complying Development Certificate through a private certifier, which is significantly faster. Heritage listings and conservation areas remove the CDC option, which matters in suburbs like Hunters Hill, Beecroft and parts of the inner west. We confirm which pathway applies to your property before quoting.
How long does a home extension take to build?
Most extensions run 12 to 20 weeks on site. Design and approvals happen before that and can add anywhere from six weeks for a CDC to several months for a DA. We give you a programme with the quote, not after you have signed.
Can I live at home during the extension?
Usually yes. Because the work is concentrated at the rear or side, most families stay in the house for most of the build, with a shorter disruptive period when we break through and connect the new space to the old. We plan the breakthrough stage with you so you know exactly when it is coming.
Should I extend out or go up with a second storey?
It comes down to land, structure and budget. Extending out is usually simpler and cheaper per square metre if you have the yard to spare. Going up preserves the yard but involves more structural work to the existing home. We build both, so the advice is honest: we look at your block and tell you which one your home actually wants. See our second storey additions page for that path.
Will the extension match the existing house?
That is a design decision, and both answers can work: matched brick and rooflines that make the extension invisible, or a deliberately contemporary addition that lets the original house be itself. What must always match is the standard of the junction between them, which is where our detailing does its work.
How will I know what is happening during my extension?
Two ways. You get a weekly update from the builder running your job, whether or not there is good news in it. And you get access to our client portal, where you can log in any time to see your documents, selections, variations and job status. No chasing, no phone tag, no wondering.
Are you licensed and insured?
Yes. Strava Group holds NSW Builder’s Licence 487370C and carries public liability insurance and Home Building Compensation Fund cover on all residential work over the statutory threshold. You can verify the licence directly through Service NSW.

Extend your home properly.

Ready for more room?

Tell us about your property and what you want to add. We respond within 24 to 48 business hours with honest advice and real numbers, no cost, no obligation.