Trusted Renovations in St Marys for Your Home
Who We Are
Keystone Building is a family-run business based near St Marys. Since 2001, we have delivered second-storey additions, ground-floor extensions, and renovations throughout Western Sydney. Our team manages every part of your project, from initial design and engineering to council approvals and construction.
We work closely with trusted suppliers like Beaumont Tiles and James Hardie to provide high-quality materials and finishes you can rely on.
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 trust Keystone Building because:
- Family-run local experts with 20+ years' experience
- Specialists in second-storey additions and home renovations
- Fixed, transparent pricing and clear contracts
- Most renovations allow you to stay in your home during construction
- We manage your whole project from start to finish with a single point of contact.
- We work with trusted suppliers and skilled builders.
- We focus on quality, safety, and finishing your project on time.
Bringing New Life to St Marys Homes
Keystone Home Additions delivers home renovations in St Marys that perfectly balance style, practicality, and quality. Whether you’re updating a dated kitchen, opening up your living space, or adding modern touches to every room, we ensure your renovation reflects your personality and lifestyle. Our skilled team uses high-quality materials and proven techniques to deliver results that stand the test of time.
Every St Marys renovation project is approached with a personalised plan, ensuring it meets your budget and exceeds your expectations. We manage everything — from initial design and council approvals to the finishing touches — so you can enjoy the process without the stress. When you choose Keystone, you choose a renovation that adds beauty, comfort, and long-term value to your home.
Extensions and Additions that Blend Seamlessly
Need more space but don’t want to leave the home you love? Our house extensions in St Marys give you room to grow while preserving the character of your existing property. From extra bedrooms and bathrooms to expanded living areas or a second storey addition, we create functional, stylish spaces that integrate perfectly with your home’s design.
We handle the complexities — council approvals, design challenges, and construction schedules — so your project runs smoothly. Our focus is on delivering energy-efficient, durable additions that enhance both comfort and market value. With Keystone Home Additions, you can be confident your extension will be completed to the highest standards, on time and within budget.
Renovations that Add Comfort, Style, and Value
A renovation is more than a facelift — it’s a chance to reimagine the way you live. Our home renovations in St Marys are designed to improve flow, maximise natural light, and create spaces that are as functional as they are beautiful. Whether you’re remodelling a single room or your entire home, we work closely with you to bring your vision to life.
Our commitment to quality craftsmanship ensures that every detail, from joinery to paint finishes, is executed flawlessly. The result? A home that not only looks incredible but also works better for your daily needs. If you’re ready to elevate your living experience, Keystone Home Additions is the trusted partner for your St Marys renovation journey.