Ground Floor Additions St Marys - Expert Home Extensions You Can Trust
Who We Are
Keystone Building is a family-run company based near St Marys. Since 2001, we have focused on quality home extensions, renovations, and second-storey additions across Western Sydney. Our services cover design, council approvals, project management, and skilled construction to ensure smooth and reliable builds.
We offer personalised consultations and tailored solutions to meet the specific needs of St Marys homeowners, helping improve living spaces with practical, well-planned ground level house extensions.
Preserve Outdoor Space
Build vertically to maintain your backyard, garden, or pool area— ideal for smaller blocks.
Add Views and Light
Second levels can open up elevated outlooks and bring in more sunlight, enhancing both value and lifestyle.
Get More Privacy
Create spacious master suites or quiet study areas completely separated from the main living zone.
Boost Property Value
Second storey additions are a strong investment, often delivering a higher return by substantially increasing usable floor area.
Why Us?
Homeowners in St Marys choose us because:
- We are a family-run local business with deep knowledge of St Marys and Western Sydney
- We specialise in second-storey and ground-floor additions with proven expertise
- We offer fixed-price contracts with clear timelines and no hidden fees
- You can stay living in your home during construction with minimal disruption
- We provide start-to-finish project management with a single point of contact
Read more on why to choose us.
Expanding Your Space Without Moving
Keystone Home Additions specialises in ground floor additions in St Marys that give you the extra room you need without the upheaval of relocating. Whether it’s a larger kitchen, an extra bedroom, or an open-plan living space, our designs integrate seamlessly with your existing home. We prioritise layouts that enhance functionality, comfort, and style, ensuring your new addition feels like it’s always been there.
From planning and council approvals to construction and finishing touches, we handle every step of the process. Our experienced team ensures that your ground floor addition not only meets your current needs but also adds lasting value to your property, making it a smart investment for the future.
Seamless Extensions that Fit Your Lifestyle
Your home should adapt to your lifestyle, not the other way around. Our single storey extensions in St Marys are designed to give you the space you’ve been dreaming of while blending perfectly with your home’s existing style. We work closely with you to create functional spaces — from spacious family rooms to private guest suites — that improve both comfort and convenience.
We pride ourselves on delivering projects that are on time, on budget, and built to last. Using quality materials and proven building techniques, we ensure your new ground floor addition is as durable as it is beautiful. The result? More room, more comfort, and a home that works better for you.
Adding Value and Versatility to Your Home
A home addition in St Marys is more than just extra space — it’s an opportunity to enhance how you live every day. Whether you want to extend your dining area for family gatherings or create a dedicated home office, our designs maximise your home’s potential while maintaining its character. We focus on optimising natural light, improving flow, and ensuring every square metre is put to good use.
Keystone Home Additions takes care of everything, so you can enjoy the excitement of your new space without the stress. Our expert team delivers high-quality, customised solutions that transform your home into a place that truly meets your needs now and into the future.