Home Extensions Baulkham Hills

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

Home Extensions · Baulkham Hills NSW 2153

Home extensions in Baulkham Hills, done properly.

Rear and side house extensions for Baulkham Hills 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 Baulkham Hills 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 Baulkham Hills.
  • 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

Baulkham Hills blocks have the room to extend.

Strava Group builds home extensions in Baulkham Hills: rear additions, side extensions and whole-of-back transformations that open the house to the yard. Baulkham Hills has some of the most extendable housing in Sydney: single storey brick homes from the 1960s through the 1980s on blocks that were subdivided when land was cheap, often with a big backyard that the original house barely uses.

In Baulkham Hills 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 Baulkham Hills.

A 1970s Baulkham Hills brick home with a galley kitchen, a separate dining room and a concrete patio out the back is the brief we see most. Open the back, bring the kitchen into the light, and connect it to the yard.

Local knowledge

What we know about extending in Baulkham Hills.

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

Council

Baulkham Hills 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. 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

Predominantly brick veneer and full brick single storey homes from the 1960s to the 1980s, with later two storey project homes on the newer estates toward Bella Vista. The older homes have small kitchens at the rear, separate dining and living rooms, and a back door onto a patio. The layout is the problem, and an extension is how you fix it.

Structure

Brick veneer homes of this era are straightforward to extend, with timber framed walls and trussed or conventional roofs that take a new structural opening well once the load path is engineered. Older full brick homes need more care at the junction: we cut the openings cleanly, install engineered steel and tie the new frame into the existing brickwork properly.

Yard and block

Standard Baulkham Hills blocks are typically 600 to 900 square metres, with the older streets near Windsor Road and Seven Hills Road often larger. That leaves room for a full width rear extension while keeping a real backyard. Many blocks fall toward the creek lines, so we check the slope early because it drives the footing design and the cost.

Services and ground

Much of the Hills sits on shale and clay derived soils, which 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 or strip footings so the two do not settle at different rates. Sewer lines often run along the rear of Baulkham Hills blocks, so we locate them early and design around them.

Value

Baulkham Hills is an established family suburb with Norwest, the Metro at Bella Vista and Norwest, and good schools holding demand. A well built extension that converts a dated rear layout into open plan living with a genuine yard connection 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 to a bigger house nearby.

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 Baulkham Hills 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 Baulkham Hills.

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 Baulkham Hills the larger blocks tend to push projects toward the middle and upper part of the band, because there is room to build a proper open plan rear rather than a single room. How much of the existing structure has to change is usually the largest single factor, followed by wet areas, sloping sites and how far the new footings have to go to find good ground.

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 Baulkham Hills.

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

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

Good to know

Baulkham Hills extension questions.

How much does a home extension cost in Baulkham Hills?
Most home extensions in Baulkham Hills 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 larger Hills blocks tend to support bigger open plan extensions, which pushes projects toward the middle of the band.
Do I need council approval for an extension in Baulkham Hills?
Usually yes, but often not a full DA. Many Baulkham Hills 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. Heritage items and some bushfire or flood affected sites near the creeks remove the CDC option. We confirm which pathway applies to your property before quoting.
How long does a home extension take to build in Baulkham Hills?
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 Baulkham Hills 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 Baulkham Hills?
On a typical Baulkham Hills block, extending out is usually the simpler and cheaper path per square metre because there is land to spare. Going up makes more sense when you want to keep every metre of yard or when the block is one of the tighter newer lots. 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 in Baulkham Hills page for that path.
Will the extension match my existing brick house?
That is a design decision, and both answers can work. Matching 1970s face brick exactly is often impossible because the brick is no longer made, so we either source the closest match and blend it, 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 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 Baulkham Hills 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.