Window Replacement for Heritage and Art Deco Unit Blocks

Sydney has hundreds of inter-war and Art Deco apartment buildings, especially in the Eastern Suburbs, the lower North Shore, Potts Point, Elizabeth Bay and the Inner West. Many are in heritage conservation areas and a few are individually listed. Their windows are often original timber or steel, now draughty, rattling and hard to open. Replacing them is possible, but it takes more care than a 1970s block, both in the design and in the approvals.

Start with what the building is

Before anyone draws a window, find out the building's heritage status. Your council's local environmental plan shows whether the building is a listed heritage item or sits in a heritage conservation area. That decides what approval is needed and how closely the new windows must match the originals. A listed building usually needs a development application with a heritage report. A building in a conservation area often needs approval for changes visible from the street.

What usually has to be kept

• The pattern of glazing bars and the proportions of the panes
• The way windows open, for example casements that stay casements
• Frame sightlines close to the originals, so the facade does not look heavier
• Colours that suit the period, often confirmed with council
• Original leadlight or decorative glass, which can sometimes be kept and protected rather than replaced

Which frame suits an older building

uPVC casements with applied glazing bars can match the look of many inter-war windows while giving full double glazing, and they are available in heritage colours and woodgrain finishes. Thermally broken aluminium gives the slimmest sightlines, which can suit steel-framed Art Deco windows. Which one council accepts depends on the building, and we prepare product drawings and samples so the heritage adviser can judge the actual window.

Older buildings need careful installation

Inter-war buildings were not built square. Openings vary from one floor to the next, sills are often damaged, and old steel frames may be built into the brickwork. Each opening is measured separately and the frames are made to fit. Where the old frame cannot come out cleanly, the repair is planned and priced before work starts, not discovered halfway through. A strata committee member wrote after one of our projects: "These old buildings are tricky and your team managed everything really well."

The approval pack we prepare

• Window schedule for every opening, with sizes, opening type and glazing
• Elevation drawings comparing existing and proposed windows
• Product data, colour and finish samples
• Energy and acoustic performance, including WERS ratings where available
• Information for your heritage consultant or the council heritage adviser