A sealed, breathable envelope
Every external wall and roof plane is wrapped in a Proclima membrane, every join, lap, penetration and window reveal taped into one continuous air and weather barrier.
Learn more
Alterations and additions
Alterations and additions by Avern.
Most of our projects are a journey that takes close collaboration, communication and problem solving. Alterations and additions are where that matters most, working with an existing structure.
Recent work includes alterations and additions to a home in Point Piper, completed in February 2026, and a renovation of a federation home in Leichhardt with a second storey added, completed in April 2026.
Built to the Avern standard
What goes into every build.
Concrete subfloors, not particleboard
Where a home is not on a slab we lay AlphaFloor 35 mm precast concrete panels. Rain on site cannot swell them, and they add thermal mass and quiet.
Learn moreStraight LVL wall framing
LVL replaces standard MGP pine in every wall frame. It stays straight and plumb, so the membrane and insulation stay continuous.
Learn moreDouble glazed, thermally broken windows
Our minimum on every project. We push for uPVC or timber frames, which do not run hot and cold the way aluminium does.
Learn moreProjects
Alterations and additions we have built.
Point Piper
Alterations and additions. Completed February 2026.
View project
Leichhardt 02
Renovation and second storey addition. Completed April 2026.
View projectYes. We renovated a federation home in Leichhardt and added a second storey, completed in April 2026.
We bring the same methods to new work wherever the existing structure allows, and explain the options at the consultation.
Yes. We offer initial consultations, complete tender submissions and general advice on construction and project management.
We are based at 159 Allen Street, Leichhardt, and build across Sydney, with projects in Point Piper, Abbotsford, Denistone East and Oatlands.
Start your project
Planning alterations and additions in Sydney?
Tell us about your site and plans. Whether it is a new home, a duplex or an addition, we will talk you through how we would build it.