Home Extensions Kellyville

Covered alfresco and outdoor living area flowing to a pool, the kind of indoor outdoor connection a home extension in Kellyville creates

Home Extensions · Kellyville NSW 2155

Home extensions in Kellyville, done properly.

Rear and side house extensions for Kellyville 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.

★★★★★Rated 5.0 by our clients on Google
NSW Builder’s Licence 487370CItemised quotesClear inclusions & exclusionsHills Shire Council area

Start here

Tell us about your Kellyville 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 in Kellyville.
  • 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

Extending a Kellyville home the right way.

Strava Group builds home extensions in Kellyville: rear additions, side extensions and whole-of-back transformations that open the house to the yard. Kellyville is younger than most suburbs we build in: the older streets near Windsor Road carry homes from the 1980s and 90s on generous blocks, while the newer release areas run tighter lots with larger two storey houses. The two halves of the suburb extend differently, and the first thing we work out on site is which one your home belongs to.

In Kellyville 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.

On the older Kellyville blocks the question is how much of the yard to use. On the newer estates it is how to add space within tighter setbacks. Both have good answers, and both start with the block, not the brochure.

Local knowledge

What we know about extending in Kellyville.

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

Council

Kellyville sits in The Hills Shire Council area under The Hills Local Environmental Plan 2019 and the Hills Development Control Plan. Most detached homes on standard residential zoning can pursue a ground floor extension through Complying Development with a private certifier rather than a full DA, subject to setbacks, site coverage and landscaped area, which bite harder on the smaller release-area lots. We confirm the pathway for your property before quoting. Current planning controls are published by Hills Shire Council and on the NSW Planning Portal.

Housing stock

Brick veneer and full brick homes from the 1980s and 90s on the established streets, and larger two storey project homes on the newer estates toward North Kellyville. The older homes have the classic layout problem: formal rooms at the front, a modest kitchen, and a back door onto a paved area. The newer homes are bigger but often short a living zone or an alfresco connection worth having.

Structure

Brick veneer homes of this era are straightforward to extend, with timber framed walls and trussed roofs that take a new structural opening well once the load path is engineered. On the newer two storey homes the extension has to respect the existing structure above, so the load path work is done carefully before anything is promised.

Yard and block

The established Kellyville blocks are typically 700 to 1,000 square metres, which leaves room for a substantial rear extension while keeping a real backyard. The newer release lots run 300 to 500 square metres, where site coverage and landscaped area controls shape what can be added, and the design has to earn every square metre. We tell you honestly what your lot will carry before you spend money on design.

Services and ground

Kellyville sits on shale and clay derived soils that move with moisture. New footings on an extension have to be engineered for the site class, not copied from the original house, and detailed against the existing slab so the two do not settle at different rates. On the newer estates the services are modern and well documented, which simplifies the design stage.

Value

Kellyville is one of the growth centres of the Hills, with the Metro, the schools and the town centres holding demand. A well built extension that gives a 1990s house the open plan rear it never had, or adds the living zone a newer home is missing, is one of the most reliable improvements you can make here, and it usually costs less than the stamp duty and agent fees involved in moving.

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 Kellyville 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 Hills clay soils make it more likely, not less.

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 Kellyville.

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.

In Kellyville the established blocks support substantial extensions in the middle of the band, while the tighter release lots keep footprints smaller and costs lower. How much of the existing structure has to change is usually the largest single factor, followed by wet areas and site coverage limits on the newer lots.

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


Nearby

Home extensions near Kellyville.

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

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

Good to know

Kellyville extension questions.

How much does a home extension cost in Kellyville?
Most home extensions in Kellyville 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. The established blocks support bigger extensions toward the middle of the band, while the newer release lots keep footprints and costs smaller.
Do I need council approval for an extension in Kellyville?
Usually yes, but often not a full DA. Many Kellyville homes qualify for a Complying Development Certificate through a private certifier, provided the extension meets the setback, site coverage and landscaped area controls, which is much faster than a DA through The Hills Shire Council. The controls bite harder on the smaller release-area lots, so we check them against your block before quoting.
How long does a home extension take to build in Kellyville?
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 Kellyville 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 Kellyville?
On the established Kellyville blocks, extending out is usually the simpler and cheaper path because the land is there. On the newer estates many homes are already two storey, so the answer is more often a rear extension or a better connection to the outdoor space. 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. See our second storey additions page for that path.
Will the extension match my existing brick house?
In Kellyville, more often than most suburbs, yes: 1990s and 2000s bricks are close to current production, so a near match can usually be sourced and blended. Where it cannot, we render the junction or design a deliberately contemporary addition that lets the original house be itself. 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 Service NSW.

Extend your Kellyville 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.