info@keystonebuilding.com.au
02 4722 5466
5.0
40+ GOOGLE REVIEWS

Custom Home Design Services

Every successful home renovation, Extension, or Second-Storey Addition begins long before the first wall goes up. It begins with a design that genuinely understands how you want to live. Keystone Building's custom home design services turn a rough idea into a considered, buildable plan, so you can see, refine, and cost your project before construction ever starts.

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Designed Around Your Budget

We shape every concept to a realistic build cost from day one, so your plans are something you can actually construct, not just admire.

Council-Ready From the Start

Our designs are prepared with local planning controls in mind, smoothing the path through CDC or DA approval.

Built to Be Built

Because we design and construct under one roof, every plan is grounded in what is genuinely buildable on your block.

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See It Before You Build It

Clear concept drawings help you visualise the finished space and make confident decisions early.

Design That Starts With You

The best designs are never pulled from a catalogue. They respond to how you actually use your home, where the light falls, how your family moves through the day, and what you want each space to become. Our home design services begin by understanding all of this before we put pen to paper, so the finished concept fits your life rather than forcing your life to fit a template.

Keystone Building provides home design services to homeowners across Western Sydney and the Greater Sydney region, including Penrith, Blacktown, The Hills District, Parramatta, South-West Sydney, Ryde, Liverpool, Canterbury-Bankstown, Fairfield, Inner West, Blue Mountains, Hawkesbury  and surrounding areas.

A thoughtful design also protects your investment. Getting the layout, orientation, and flow right on paper is far cheaper than changing your mind mid-build, and it gives every trade a clear, costed roadmap to follow. Whether you are planning a Ground Floor Extension, a new storey, or a full renovation, good design is what keeps a project on time and on budget.

Not sure your ideas will actually work?

Struggling to picture the finished result?

Worried about designing something you cannot afford to build?

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Before & After

Your Home, Transformed

Great design does not just change your floor plan, it changes how every day in your home feels.

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BEFORE
AFTER
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"Keystone Building should be the Australian Standard for the construction and service industry. I would highly recommend this company to anyone looking to add to their home."

S. Courtis
Why Choose Us?

Built on Over 25 Years of Experience

We're a local, family-owned business known for our integrity and attention to detail, specialising in Extensions and Second Storey Additions for over 25 years.
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We’re a tight-knit crew of qualified Builders, Carpenters, and Project Managers who take pride in every job. Whether you’re talking with us on-site or in the office, you’ll find years of experience in our friendly, professional team. We're here to help you achieve your dream home.

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Built On Time & Budget

We’re committed on completing your build on time and within budget.

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Stay Home While We Build

Most clients stay in their homes during construction, no need to pay for rent or storage.

Minimal Disruption

We keep noise, mess, and intrusion low, cleaning up daily and protecting your living space.

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Customer-First Approach

We design with your lifestyle in mind and keep you involved every step of the way.

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No Hidden Costs

Clear, detailed pricing in your contract—no surprises or unexpected charges.

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Trusted Family Business

Delivering quality Extensions & Second Storey Additions since 2001 with honesty and care.

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Featured Projects

EXPLORE PROJECTS

Winston Hills

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A two-storey brick and weatherboard home set behind a garden with tall palm trees on a sunny day.

Cranebrook

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A grey, double-storey house, with a black roof, single garage, and a carport on a cloudless day.

Jamisontown

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Pennant Hills

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A two-storey house with a grey weatherboard upper level above a red-brick ground floor, a tiled roof, and a double garage with cream doors.

Glenmore Park

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An aerial view of a white two-storey house with a grey roof, a double garage, and a landscaped front garden.

Blacktown

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Our Refined Process

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1. Free Introductory Session

We start with an initial consultation to understand what you want to achieve, your timeframe, and your budget, so we can tell you honestly whether the project stacks up.

2. Free Design Consultation

Our design team visit your home to assess the site, take measurements, and talk through ideas and layouts, exploring what is realistically possible on your block.

3. Formal Concept Design and Proposal

We translate your brief into custom floor plans and a clear, itemised proposal, so you can see the design and its build cost side by side.

4. Plans and Approvals

We prepare the detailed documentation and manage your Complying Development Certificate (CDC) or Development Application (DA) submission with your council.

5. Preparing to Build

We finalise your selections, materials, and finishes, then schedule the build so everything is ready before work begins.

6. Construction Phase

The same team that designed your home builds it, keeping the finished result faithful to the plans you approved throughout the entire construction process.

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Free introductory session

A phone call where we get to know you, talk about your ideas, budget and goals.

Free Design Consultation

Site visit by our consultant who will sit down with you to address every concept of your proposed build.

Formal Concept Design and Proposal

Concept plan prepared by a Building Designer and formal proposal prepared.

Plans and Approvals

Detailed plans prepared and submitted to relevant authority for assessment and approval.

Preparing to Extend

We prepare you for the construction phase.

Construction Phase

This is when the real work begins – it’s time to turn your dream home into a reality!

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5.0
40 REVIEWS ON GOOGLE

Our Happy Customers

  • "To everyone who is reading this with intention to build a first floor addition, your search should end here.”
    Andrea
    NSW
  • "Thank you so much for all your dedicated hard work and especially your consideration to our family during the renovation of our home.”
    Tracey, Jason, Liam & Mackenzie Brown
    NSW
  • “All the tradesman involved in the renovation process were prompt, courteous and very meticulous.”
    Cathy & Stephen Bone
    NSW
  • "Their workmanship is second to none that I have seen and the service and tradespeople they used were fantastic."
    Reginald Moodley
    Penrith
  • "The staff was very friendly and kept our premises spotless and clean. Nothing was too difficult or out of their way. "
    Neil Moodley
    Glenmore Park
  • "The whole process was professional, on time and on budget. The tradesmen were all brilliant and meticulous.”
    Chris and Jim
    Harrington Park
"Their workmanship is second to none that I have seen and the service and tradespeople they used were fantastic."
Reginald Moodley
Penrith
"The staff was very friendly and kept our premises spotless and clean. Nothing was too difficult or out of their way. "
Neil Moodley
Glenmore Park
"The whole process was professional, on time and on budget. The tradesmen were all brilliant and meticulous.”
Chris and Jim
Harrington Park
"To everyone who is reading this with intention to build a first floor addition, your search should end here.”
Andrea
NSW
"Thank you so much for all your dedicated hard work and especially your consideration to our family during the renovation of our home.”
Tracey, Jason, Liam & Mackenzie Brown
NSW
“All the tradesman involved in the renovation process were prompt, courteous and very meticulous.”
Cathy & Stephen Bone
NSW
"Their workmanship is second to none that I have seen and the service and tradespeople they used were fantastic."
Reginald Moodley
Penrith
"The staff was very friendly and kept our premises spotless and clean. Nothing was too difficult or out of their way. "
Neil Moodley
Glenmore Park
"The whole process was professional, on time and on budget. The tradesmen were all brilliant and meticulous.”
Chris and Jim
Harrington Park
"To everyone who is reading this with intention to build a first floor addition, your search should end here.”
Andrea
NSW
"Thank you so much for all your dedicated hard work and especially your consideration to our family during the renovation of our home.”
Tracey, Jason, Liam & Mackenzie Brown
NSW
“All the tradesman involved in the renovation process were prompt, courteous and very meticulous.”
Cathy & Stephen Bone
NSW
"Their workmanship is second to none that I have seen and the service and tradespeople they used were fantastic."
Reginald Moodley
Penrith
"The staff was very friendly and kept our premises spotless and clean. Nothing was too difficult or out of their way. "
Neil Moodley
Glenmore Park
"The whole process was professional, on time and on budget. The tradesmen were all brilliant and meticulous.”
Chris and Jim
Harrington Park
"To everyone who is reading this with intention to build a first floor addition, your search should end here.”
Andrea
NSW
"Thank you so much for all your dedicated hard work and especially your consideration to our family during the renovation of our home.”
Tracey, Jason, Liam & Mackenzie Brown
NSW
“All the tradesman involved in the renovation process were prompt, courteous and very meticulous.”
Cathy & Stephen Bone
NSW
"Their workmanship is second to none that I have seen and the service and tradespeople they used were fantastic."
Reginald Moodley
Penrith
"The staff was very friendly and kept our premises spotless and clean. Nothing was too difficult or out of their way. "
Neil Moodley
Glenmore Park
"The whole process was professional, on time and on budget. The tradesmen were all brilliant and meticulous.”
Chris and Jim
Harrington Park
"To everyone who is reading this with intention to build a first floor addition, your search should end here.”
Andrea
NSW
"Thank you so much for all your dedicated hard work and especially your consideration to our family during the renovation of our home.”
Tracey, Jason, Liam & Mackenzie Brown
NSW
“All the tradesman involved in the renovation process were prompt, courteous and very meticulous.”
Cathy & Stephen Bone
NSW
"Their workmanship is second to none that I have seen and the service and tradespeople they used were fantastic."
Reginald Moodley
Penrith
"The staff was very friendly and kept our premises spotless and clean. Nothing was too difficult or out of their way. "
Neil Moodley
Glenmore Park
"The whole process was professional, on time and on budget. The tradesmen were all brilliant and meticulous.”
Chris and Jim
Harrington Park
"To everyone who is reading this with intention to build a first floor addition, your search should end here.”
Andrea
NSW
"Thank you so much for all your dedicated hard work and especially your consideration to our family during the renovation of our home.”
Tracey, Jason, Liam & Mackenzie Brown
NSW
“All the tradesman involved in the renovation process were prompt, courteous and very meticulous.”
Cathy & Stephen Bone
NSW
"Their workmanship is second to none that I have seen and the service and tradespeople they used were fantastic."
Reginald Moodley
Penrith
"The staff was very friendly and kept our premises spotless and clean. Nothing was too difficult or out of their way. "
Neil Moodley
Glenmore Park
"The whole process was professional, on time and on budget. The tradesmen were all brilliant and meticulous.”
Chris and Jim
Harrington Park
"To everyone who is reading this with intention to build a first floor addition, your search should end here.”
Andrea
NSW
"Thank you so much for all your dedicated hard work and especially your consideration to our family during the renovation of our home.”
Tracey, Jason, Liam & Mackenzie Brown
NSW
“All the tradesman involved in the renovation process were prompt, courteous and very meticulous.”
Cathy & Stephen Bone
NSW
"Their workmanship is second to none that I have seen and the service and tradespeople they used were fantastic."
Reginald Moodley
Penrith
"The staff was very friendly and kept our premises spotless and clean. Nothing was too difficult or out of their way. "
Neil Moodley
Glenmore Park
"The whole process was professional, on time and on budget. The tradesmen were all brilliant and meticulous.”
Chris and Jim
Harrington Park
"To everyone who is reading this with intention to build a first floor addition, your search should end here.”
Andrea
NSW
"Thank you so much for all your dedicated hard work and especially your consideration to our family during the renovation of our home.”
Tracey, Jason, Liam & Mackenzie Brown
NSW
“All the tradesman involved in the renovation process were prompt, courteous and very meticulous.”
Cathy & Stephen Bone
NSW
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Our trusted suppliers

Our long-standing relationships with reputable brands mean the premium finishes and materials we specify in your design are ones we know and trust. By partnering with specialists in each product category, we can guide your selections with confidence, offering a wide choice, competitive pricing, and materials that meet Australian standards and stand the test of time.

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Home Design Services FAQs

Find answers to the most common questions you may have.

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What happens if I want to change the design once building has started?

Changes are always possible, but they cost far more once trades are on site. Settling the design and finishes before construction is the surest way to avoid variations, delays, and budget blowouts.

Can the design help my home meet BASIX and energy requirements?

We always factor in orientation, glazing, insulation, and ventilation at the design stage to satisfy NSW BASIX requirements. These factors also help lower running costs for the life of the home.

How long does the design stage take?

Concept design usually takes a few weeks. Detailed documentation and approval-ready plans take longer, depending on the scale of the project and your council's requirements.

Can you work from plans an architect or draftsperson has already prepared?

We can review, refine, or cost existing plans and flag any buildability or approval issues before you commit, which often saves expensive changes later.

5.0
40+ GOOGLE REVIEWS

Start your home Transformation

Your first consultation and quote are on us!

Get a free consultation and quote with no obligation.
Share your plans and speak directly with our team.
Ask questions about timing, approvals, or next steps.
info@keystonebuilding.com.au
02 4722 5466
Unit 1, 29 Coombes Drive, Penrith 2750
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