Published 18 September 2026.
If a Melbourne home feels cold even when the heating is running, the windows may be one part of the problem — but they are not automatically the only cause. Draughty windows can allow unwanted air leakage, while older glazing and conductive frames can also contribute to heat transfer. Insulation, doors, floors, ceilings and other parts of the building envelope should be considered as well.
Why Can I Feel Cold Air Around a Closed Window?
Possible causes include worn or damaged seals, gaps around an opening sash, distorted frames, ageing hardware, or gaps where the window meets the surrounding wall construction. Identifying the source matters because replacing glass alone will not correct every type of draught.
Does Single Glazing Make a Room Feel Colder?
Single glazing provides less resistance to heat transfer than an appropriately specified insulated glass unit. The indoor glass surface can also feel colder during winter conditions. However, overall comfort depends on the complete window system and the rest of the building envelope.
Will Double Glazing Fix Draughty Windows?
Not necessarily. Double glazing addresses heat transfer through the glazed area, while draughts are primarily an air-leakage issue. If an existing frame or its seals are in poor condition, simply changing the glass may not address the leakage path. Homeowners considering a complete upgrade can read our double-glazed window replacement guide.
Should I Repair the Window or Replace It?
If the problem is isolated to serviceable hardware or seals and the overall frame remains suitable, repair may be worth investigating first. Replacement becomes more relevant when the complete frame is deteriorated, operation is poor, many windows have similar problems or the homeowner is already planning a substantial renovation.
See our guide to deciding when old windows should be replaced.
What About Old Timber Windows?
Ageing timber frames may develop deterioration or sealing issues over time. Where replacement is being considered, custom aluminium windows can often be manufactured for the measured opening, subject to the property’s construction and installation conditions. See our timber-to-aluminium window replacement guide.
Could the Frame Affect Thermal Performance?
Yes. Glass is only one part of the window. Standard aluminium and thermally broken aluminium frames have different thermal characteristics. A thermally broken system uses a low-conductivity separation within the frame to reduce direct heat transfer through the aluminium. The appropriate choice depends on the project’s performance requirements and budget.
What Should I Check Before Requesting a Quote?
- Which rooms feel draughty or uncomfortable?
- Can you feel air movement around the sash or around the outer frame?
- Are the windows difficult to close or lock?
- Are the existing frames timber or aluminium?
- Is the glass single or double glazed?
- Are you considering one room or a whole-house upgrade?
What Should I Send JL Windows?
For an initial replacement review, send your suburb, clear photos from inside and outside, approximate window dimensions and a short description of the issue. Architectural plans are not required to start.
For replacement pricing, see our window replacement cost guide.
