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Built Once. Built Right.

Timber roof and wall framing in a renovation

Home Extensions · Summer Hill NSW 2130

Home extensions in Summer Hill, done properly.

Rear and side house extensions for Summer Hill 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.

Master Builders Association NSW member
NSW Licensed Builder
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 Summer Hill home.

Strava Group builds home extensions in Summer Hill: rear extensions, side returns and whole-of-back transformations that open the house to the yard. Summer Hill is one of the prettiest village suburbs in the inner west: Victorian and Federation houses, a high proportion of semis, tree-lined streets and heritage conservation areas protecting most of it. The front halves of these houses are worth keeping. The back halves, where the kitchens and bathrooms were squeezed in, are where the extension does its work.

In Summer Hill 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 typical Summer Hill brief is a Federation semi or cottage 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.
Waterfall-edge island in grey woodgrain cabinetry with tall pantry and integrated fridge space
?

Quick Answer

Most home extensions in Summer Hill 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 Summer Hill.

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

Council

Summer Hill is in the Inner West Council area under the Inner West Local Environmental Plan 2022, and most of the suburb sits inside heritage conservation areas. That removes the Complying Development pathway for most extensions, so projects go through a Development Application. A rear extension that sits behind the original roofline, respects the neighbouring semi and is not visible from the street is well supported by the controls. 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

Victorian and Federation houses across most of the suburb, a high proportion of semis, some grander homes near the village and a scatter of interwar and post-war brick. Many carry a lean-to kitchen or fibro sunroom added decades ago that was never built to last. Those earlier additions usually come off and are replaced with something engineered.

Structure

Semis 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, and the new floor has to meet the existing suspended timber floor exactly.

Yard and block

Blocks are mostly 250 to 450 square metres and narrow, so 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

Summer Hill sits on shale derived clay soils that move with moisture, with lower ground toward Hawthorne Canal where flood controls can apply. The footings under a Victorian or Federation 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 are located before design starts.

Value

Summer Hill is one of the most tightly held pockets of the inner west, with the village, the station and the light rail keeping demand strong. Buyers pay a premium for a character house or semi with a properly built modern rear, and an extension that keeps the original front and opens the back to the yard is one of the safest improvements you can make here.

Built Once. Built Right.

See exactly how we build, and why

Four-coat waterproofing, tensioned X bracing, hand-cut roofs and inspections you can check yourself. Every method explained, including what’s standard and what’s an upgrade.

Start here

Tell us about your Summer Hill home.

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

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

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 Summer Hill 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 Summer Hill.

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.

ItemTypical range
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: 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 Summer Hill the small 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 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

Summer Hill extension questions.

From our clients

Rated 5.0 on Google.

5.0·Google reviews
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.
AT

Aloona T.

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Nearby

Home extensions near Summer Hill.

We build extensions across Inner West and the surrounding suburbs. Select a suburb for local council information and what extensions there typically cost.

Inner West

All Sydney extension areas

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

Extend your Summer Hill 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.