Do I need council approval for an extension in Marrickville?

Almost always yes, and in Marrickville it is usually a Development Application rather than a Complying Development Certificate, because much of the suburb sits inside heritage conservation areas under the Inner West LEP 2022. A rear extension that is not visible from the street is well supported. Outside the conservation areas a CDC may be possible. On a semi or terrace we also manage the neighbour notification and party wall process. We confirm which pathway applies to your property before quoting.

How long does a home extension take to build in Marrickville?

Most extensions run 12 to 20 weeks on site. Design and approvals happen before that: a CDC takes about 4 to 8 weeks, and a DA can take up to 6 months, depending on council. 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 Marrickville 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 add a second storey in Marrickville?

On a typical Marrickville block, a rear extension is usually the first option because it keeps the original front of the house intact and the heritage controls favour work that sits behind the existing roofline. Going up is harder in conservation areas and on semis and terraces, but it can be the right call on a small block where the yard has to be kept. We build both, so the advice is honest: we look at your block and tell you which one your home actually wants. A house extension and a second storey are different builds with different engineering, and we quote both honestly.

Can you extend a semi without affecting the neighbour?

Yes, if it is engineered properly. The new structure is designed so it does not load the party wall beyond what it was built for, the footings are detailed so the extension does not pull on the shared wall as it settles, and the neighbour is kept informed from the notification stage through to completion. Matching or contrasting the original is then a design decision, and in the conservation areas council generally prefers the rear to read as clearly new. What must always match is the standard of the junction between old and new, 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 Verify NSW at verify.licence.nsw.gov.au.

Timber roof and wall framing in a renovation

Home Extensions · Marrickville NSW 2204

Home extensions in Marrickville, done properly.

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

Get Your Extension Assessed Call 0450 605 080

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487370C

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Inner West Council areaNSW Builder’s Licence 487370CItemised quotesClear inclusions & exclusions0450 605 080

Extending out, not up

More room at the back of a Marrickville home.

Strava Group builds home extensions in Marrickville: rear extensions, side returns and whole-of-back transformations that open the house to the yard. Marrickville is a mix of Federation semis and cottages, Victorian terraces near the station, interwar bungalows on the wider streets and a good stock of post-war brick. Much of it sits in heritage conservation areas. On the semis and terraces the extension is always a custom project built around a party wall. On the freestanding homes it is the classic brief: keep the front, rebuild the back.

In Marrickville 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 in Marrickville.

The typical Marrickville brief is a Federation semi with good front rooms and a cramped, dark kitchen at the back. Push the living out into the yard, bring the light in, and the whole house changes.

Open-plan kitchen and dining area with a white island, bar stools and timber-look floors

Quick Answer

Most home extensions in Marrickville 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 (design, engineering and council approvals, plus site set-up) on top. Demolishing an earlier lean-to, opening double brick walls, party walls on semis and working without side access are the things that move the figure most here.

Local knowledge

What we know about extending in Marrickville.

Every suburb builds a little differently. This is what matters when you are extending a Marrickville home.

Council

Marrickville is in the Inner West Council area under the Inner West Local Environmental Plan 2022. A large part of the suburb sits inside heritage conservation areas, which removes the Complying Development pathway and means most extensions go through a Development Application. A rear extension that sits behind the original roofline and is not visible from the street is well supported by the controls. Some streets near the airport carry aircraft noise controls that affect glazing and insulation. We confirm the pathway for your property before quoting. Current planning controls are published by Inner West Council and on the NSW Planning Portal.

Housing stock

Federation semis and cottages across most of the suburb, Victorian terraces near Marrickville and Sydenham stations, Californian bungalows on the wider streets toward Dulwich Hill, and post-war brick homes built by the families who settled here after the war. Many carry a lean-to or fibro sunroom tacked onto the back decades ago. Those earlier additions usually come off and are replaced with something engineered.

Structure

Semis and terraces share a party wall, and the extension is designed around it: the new structure is tied to the existing masonry without loading the shared wall beyond what it was built for, and the neighbour is kept informed throughout. Cutting openings into old double brick rear walls needs engineered lintels and careful propping. The post-war brick homes, often full brick on a slab, extend more simply once the load path is engineered.

Yard and block

Blocks are mostly 250 to 500 square metres, with semis on the narrow end and the bungalows and post-war homes on the wider end. Side access is the first thing we check: semis often have access down one side only, and where there is none materials come through the house and the programme changes. A rear extension across the full width of the block, with a usable yard kept beyond it, is the usual move.

Services and ground

Marrickville sits on shale derived clay soils that move with moisture, with alluvial ground on the low side toward the Cooks River that needs its own footing design. The footings under a 1910s house were never engineered, so new footings are designed for the site and detailed against the old ones so the extension does not settle away from the house or pull on a party wall. Old sewer and stormwater lines often run along the rear boundary and are located before design starts.

Value

Marrickville has become one of the most sought after suburbs in the inner west, with the Metro, the station, the Addison Road and Illawarra Road strips and the creative scene holding demand. Buyers pay a premium for a semi or cottage with a properly built modern rear, and an extension that keeps the Federation front and opens the back to the yard is one of the safest improvements you can make.

Start here

Tell us about your Marrickville home.

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

One at a time, takes about two minutes, so the first conversation is about your project rather than the basics.

Start Your Enquiry Call 0450 605 080

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 Marrickville 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, and on a semi it matters twice over because the party wall has to be protected as well.

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 house extension actually costs in Marrickville.

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.

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

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

In Marrickville the smaller blocks and heritage controls tend to keep projects in the lower and middle part of the band, but party walls, narrow access and the work involved in taking off an earlier lean-to can add to it. Semi and terrace extensions are custom builds quoted on their own terms. How much of the existing structure has to change is usually the largest single factor, followed by access and wet areas.

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

Good to know

Marrickville extension questions.

From our clients

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Nearby

Home extensions near Marrickville.

We build extensions across the inner west. Select a suburb for local council information and what extensions there typically cost.

Inner West

Home Extensions Dulwich Hill Home Extensions Leichhardt Home Extensions Ashfield Home Extensions Hurstville Home Extensions Burwood

All Sydney extension areas

Looking for a different service in Marrickville? We also build second storey additions in Marrickville and home renovations in Marrickville.

Extend your Marrickville 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.

Get Your Extension Assessed Call 0450 605 080