ASAP Glass and Glazing — Glazing & Windows in Boronia

Standard aluminium single-glazed window replacement costs $400–$900 per window installed. Upcycling to double glazing costs $700–$2,000 per window. Timber frame windows cost $1,000–$3,000 each. Replacing all windows in a 3-bedroom home typically costs $8,000–$25,000 depending on material and glazing specification.

Double glazing reduces heat loss and gain through glass by 30–50%, significantly reducing heating and cooling costs. It also reduces outside noise by 30–40 decibels. Payback is typically 7–15 years through energy savings alone, but improved comfort, reduced condensation, and noise reduction add significant lifestyle value, especially in Melbourne and southern states.

Safety glass (toughened or laminated) is required by the Australian Building Code (NCC) in windows and glazed areas where human impact is likely: doors, sidelights, low windows (below 500mm from floor), bathrooms, and near stairs. Safety glass shatters into small, less harmful pieces. Replacing broken annealed glass in these locations with safety glass is legally required.

Secondary glazing adds an internal glazed panel to an existing window, creating a sealed air gap — similar in effect to double glazing at lower cost ($300–$700 per window). It's popular in heritage homes where replacing original windows is restricted. While effective, it's less thermally efficient than true double-glazing and can make windows harder to open and clean.

Like-for-like window replacements (same size, same location) generally don't require planning approval. Changing window size, location, or adding new windows to an existing house may require a building permit and sometimes planning consent. Heritage-listed properties have strict controls on window changes — always check before proceeding.