Experienced residential additions and extensions builder and designer Bring Your Home Dreams to Life!

Sydney, North Shore, Upper North Shore, Lower North Shre, NSW, Hornsby, Pymble, Mosman, Cremorne, St Ives, Roseville, Chatswood, St Leonards, Artarmon, Wahroonga, Waitara, Asquith, Dural, Crows Nest, Greenwich, Castle Hill.

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Olsen Construction are renowned home builders in Hornsby. If you are looking for an experienced, reputable and reliable builder, we offer exclusive building services including:

  1. Designing Additions & Extensions

  2. Build Additions & Extensions

  3. Additions

  4. Extensions


We are proud of the high-quality workmanship and prompt service that we provide. You can trust us with your next addition or extension, our exceptional customer service, attention to detail and superior quality work is our winning formula.

With our vast experience of more than 30 years, we specialise in providing outstanding designs for renovations. Our expert professionals have excellent problem-solving and project management skills. We always deliver splendid results even while undertaking complex projects. Our trained team works hand in hand with our clients, providing guidance to them throughout the duration of the project.

Initially, our representative visits your site personally, gives you advice on the action plan and follows up with a comprehensive quote. Then we manage your additions and deal with you directly throughout the entire work.

Our thorough knowledge of construction techniques and materials will assist you to improve your living space and to directly extend or refurbish your entire home. 

If you are seeking professional home builders with the desire to create a bigger living space, for example, if you'd like to connect your kitchen with your living room, backyard extensions or any other home renovations for your lovely home in Sydney and the nearby suburbs, contact us on (02) 9482 1000 for further details. We will be happy to see you visit our Hornsby office. Reach out to us for our expert consultation and get the best advice.

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Each project is unique and we adapt to suit each and every client.

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Meet the team that will make your project a reality.

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Check out our project gallery to see our high-end craftsmanship.

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We are a family business with family values.

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"...team was trustworthy and pleasant to have around."

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Get in touch with your project needs.

"Working with Mel and the team at Olsen Construction is a joyful process - they’re great communicators, have high attention to detail, have a great eye for design, and are extremely trustworthy builders. What they promise to deliver they do and to the highest quality of finishes, fixtures, and details.


As an interior designer who works in residential and hospitality design, working with Olsen Construction was a dream. They have such a positive outlook and to work with a building company with 30+ years experience, I knew the client would have a beautiful home after the renovation. 


The design concept, documentation and schedules were all thoroughly understood, followed and if there were any discrepancies Mel would quickly be on top of them to efficiently confirm the solution.


If you’re looking to renovate, extend, or build a brand new home, Olsen Construction are your go-to builders for a seamless, beautiful build.”



KO Designer