Second Storey Additions
When your home has outgrown its footprint but the street, schools and neighbours still feel right, a second storey addition lets you build upward instead of moving on. Also called a second storey extension or first floor addition, this style of home renovation adds a whole new level of bedrooms, bathrooms and living areas above your existing home, no backyard sacrificed.
Higher Energy Efficiency
Modern ground floor extensions use high-performance glazing, cross-ventilation, and quality insulation to keep energy bills low year-round.
Add Views and Light
Elevated rooms draw in natural light, afternoon breezes and rooftop outlooks you cannot get at ground level.
Get More Privacy
Lift master bedrooms, studies and guest rooms upstairs to free the ground floor for relaxed communal living.
Boost Property Value
Near-doubling your usable floor area is one of the most reliable ways to lift long-term equity and resale value.
More Living Space
When a growing family, a work-from-home routine or an ageing parent stretches your current layout, relocating is rarely the most sensible answer. Once you add stamp duty, agent fees, removalists and Sydney’s scarce land supply, staying put and building up almost always comes out ahead on both lifestyle and finances.
A second storey extension turns your existing footprint into a full two-level home, typically adding three to five new rooms above your ground floor while leaving the yard untouched. It is a customised alternative to a full knock-down rebuild, preserving the character of your home along with the trees, fences and landscaping you have built up over years. Compared to ground floor extensions that use more of your block, building up delivers more space, more privacy and more property value from a single project.
At Keystone Building, second storey additions and first floor additions are our daily work across Western Sydney, from Penrith, Kingswood, Cranebrook and Jamisontown through to Mulgoa, Wallacia, Wilberforce, Windsor, Dural, Seven Hills, St Marys, Orchard Hills, Claremont Meadows, Colyton, Leonay, Regentville, Londonderry and Llandilo. Our in-house team manages concept design, engineering, council applications and on-site construction, so one trusted builder carries you from the first consultation through to handover.
Pairing a new upper level with a ground floor refresh, such as an open-plan kitchen, a reconfigured entry or updated bathrooms, lifts both liveability and market value in one coordinated program. Whether you are future-proofing for a larger family or preparing to sell in five or ten years, this style of home renovation keeps paying you back in both new space and equity.
Feeling cramped in your own space?
Is your yard underused or impractical?
Not keen on extending upwards?
Before & After
Your Home, Transformed
A ground floor extention doesn’t just add space—it changes everything.
"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."
Why Choose Us?
Built on Over 30 Years of Experience
A second storey adds an entirely new dimension to your home, opening up a world of opportunity to accommodate for your lifestyle. Here’s why people choose Keystone to complete their second storey addition.
Built On Time & Budget
We’re committed on completing your build on time and within budget.
Stay Home While We Build
Most clients stay in their homes during construction, no need to pay for rent or storage.
Disruption Kept to a Minimum
We keep noise, mess, & intrusion low, cleaning up daily and protecting your living space.
Customer-First Approach
We design with your lifestyle in mind and keep you involved every step of the way.
No Hidden Costs
Clear, detailed pricing in your contract—no surprises or unexpected charges.
Trusted Family Business
We’ve delivered quality second storey additions since 1997 with honesty and care.
Our Refined Process
We're based in Penrith, and work across Western Sydney, the Hills District, South-West Sydney, and surrounding areas including the Hawkesbury and Blue Mountains.
Most Second Storey Additions take between four to eight months, depending on complexity, weather, and council approvals. Your build is unique and we'll provide a clear timeline during the planning phase.
No, most homeowners are able to live in their homes during the average second storey addition or extension. Of course, it depends on how much you're getting done to the original part of your home, and personal preference. In some cases, especially during demolition or structural work, it may be safer and more practical to vacate the property temporarily. We’ll discuss this with you upfront so you can plan accordingly.
Yes, the ground floor must be able to support the additional weight of the second storey. Our structural engineers will assess your property and design neccessary reinforcements, and we'll manage all the nitty gritty stuff, like applications to Council / Building Certifier and other authorities.
Costs vary widely dependant on your requirements, but the average second-storey addition can range from $200,000 to $400,000. We’ll provide a detailed quote specific to your needs and site conditions.
Yes! For 95% of our projects, yes you can still live in your home during construction. Keystone commits to keeping your home clean and secure. We make every effort to keep the disruption to an absolute minimum so you can stay in your home as we build, but there will always be some dust, dirt and noise. Our friendly tradesmen use drop sheets and clean up after themselves at the end of every day’s work.
On average it takes from 2 to 5 months but it may take longer depending on the size of your extension. No matter how big the job, Keystone gives you a precise and fixed build time bound by a contract with penalty clauses.
Your Project Manager will be readily available to answer any questions, and will also visit and/or call you for decision making to keep you updated. You will have their phone number to call if you have any questions.
Yes, Keystone has a number of unique guarantees to give you greater peace of mind. Get in touch to find out more.
Yes, all second floor additions require approval from your local council. We manage this as part of our service, ensuring plans meet all zoning and compliance requirements.
Yes, Keystone handles everything! Our friendly team will manage all the necessary approvals and documents required for work to proceed.
No, Keystone's Building Consultants will design specifically to your needs, and our draftsman will prepare the plans for Council approval. However, if you already have an architect, we are happy to work with them to complete the project.
Yes! Keystone takes care of every aspect of the design and building process including engineering drawings and appropriate approvals.