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

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 Cheltenham 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 Cheltenham?

On a typical Cheltenham block, extending out is almost always the better path because the land is there and the conservation area controls favour work that sits behind the original house. A second storey on a heritage house is possible but needs careful design to get through council. 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.

Will the extension have to match my heritage house?

Not necessarily, and in the Beecroft Cheltenham conservation area council often prefers a rear extension that reads as clearly new rather than a copy of the original, as long as it sits behind the main roof, respects the scale of the house and is not visible from the street. Matched materials and rooflines are still an option. 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 · Cheltenham NSW 2119

Home extensions in Cheltenham, done properly.

Rear and side house extensions for Cheltenham 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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Hornsby Shire Council areaNSW Builder’s Licence 487370CItemised quotesClear inclusions & exclusions0450 605 080

Extending out, not up

Extending a Cheltenham home among the trees.

Strava Group builds home extensions in Cheltenham: rear additions, side extensions and whole-of-back transformations that open the house to the garden. Cheltenham is small, quiet and almost entirely inside the Beecroft Cheltenham Heritage Conservation Area, with large treed blocks running down toward the Lane Cove National Park. The houses were built to be seen from the street, which is why the best extensions keep the front exactly as it is and do all their work at the back.

In Cheltenham 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 Cheltenham.

A Cheltenham block usually has more garden than the house knows what to do with. A rear extension that opens the living to the trees, without touching the street face, is the brief almost every time.

Floating timber staircase with glass balustrade beside a bright living room

Quick Answer

Most home extensions in Cheltenham 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. The heritage DA process, protected trees and sloping blocks tend to push Cheltenham projects toward the middle of the band.

Local knowledge

What we know about extending in Cheltenham.

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

Council

Cheltenham is in the Hornsby Shire Council area under the Hornsby Local Environmental Plan 2013, and almost the whole suburb sits inside the Beecroft Cheltenham Heritage Conservation Area. That removes the Complying Development pathway, so extensions go through a Development Application with a heritage assessment. Rear extensions that sit behind the main roofline and keep the street presentation are well supported. We confirm the pathway for your property before quoting. Current planning controls are published by Hornsby Shire Council and on the NSW Planning Portal.

Housing stock

Federation and interwar homes on the older streets near the station, a strong stock of 1950s and 60s brick and weatherboard houses, and some later homes set deep on bush blocks toward the national park. Many have been extended once before, often with a sunroom or family room of uncertain quality. A proper rear extension usually replaces that work rather than adding to it.

Structure

The older Cheltenham homes are double brick or timber framed with weatherboard cladding on brick piers, hardwood floors and framed roofs. Cutting a new opening into an old rear wall needs an engineered lintel and careful propping, and the new floor has to meet the existing suspended timber floor exactly. Weatherboard homes extend well in timber, and the junction is where the flashing has to be done properly.

Yard and block

Blocks in Cheltenham are typically 900 square metres and upward, many of them sloping and most of them treed. The trees are protected under council controls and usually decide where the extension can go. The size of the block means a substantial rear extension is possible while keeping the garden, and on the steeper blocks the extension often steps down the site.

Services and ground

Cheltenham sits on shale derived clay over Hawkesbury sandstone, with the rock close to the surface on the slopes toward the park. Footing design varies across a single block, so the engineering is done for your site, and new footings are detailed against the existing ones so the extension does not settle away from an old house. Absorption trenches and old services on the larger blocks are located before we design.

Value

Cheltenham is tightly held and rarely built out: the conservation area, the trees and the quiet protect its value, and the station and school catchments keep demand steady. Buyers here pay for character houses that have been extended properly at the rear, and a considered extension that keeps the front intact is one of the safest improvements in the suburb.

Start here

Tell us about your Cheltenham 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 Cheltenham 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 it matters more on an older house whose original footings were never engineered to modern standards.

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 Cheltenham.

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 Cheltenham the large blocks allow substantial extensions, but the heritage process, protected trees and sloping sandstone sites add design and engineering work that pushes projects toward the middle and upper part of the band. How much of the existing structure has to change is usually the largest single factor, followed by wet areas, access around trees and how far footings have to go to find rock.

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

Cheltenham extension questions.

From our clients

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Nearby

Home extensions near Cheltenham.

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

Hornsby and the northern suburbs

Home Extensions Beecroft Home Extensions Pennant Hills Home Extensions West Pennant Hills Home Extensions Epping Home Extensions Eastwood

All Sydney extension areas

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

Extend your Cheltenham 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