Quick Answer

Draught-proofing a typical Melbourne home costs $150–$600 in materials for a full DIY job, or $400–$1,200 professionally done. It typically reduces heating and cooling bills by 15–25% and pays back in under 2 years. The biggest heat losses are under doors, around windows, through ceiling penetrations, and via the fireplace flue — fix these four areas first for the best return.

Fitting self-adhesive foam draught strip to a front door frame — doors are one of the biggest draugh
Fitting self-adhesive foam draught strip to a front door frame — doors are one of the biggest draught entry points in older Melbourne homes, and a $12 door seal kit typically pays back in the first winter.

Where Cold Air Is Getting In: The Draught Audit

Before buying any products, do a quick draught audit on a cold, windy day. Hold your hand around door frames, window edges, skirting boards, power points on external walls, and ceiling light fittings. You’ll feel cold air infiltrating — often surprisingly strongly.

The biggest culprits in SE Melbourne homes, in order of heat loss:

  1. Under exterior doors — gaps of even 5mm under a standard door let in as much cold air as a 50mm hole in the wall
  2. Around windows — warped or old timber frames, dried-out sealant, and rattling sashes
  3. Ceiling penetrations — recessed downlights, exhaust fans, attic hatches, and ducted heating/cooling vents
  4. Chimney flues — an open fireplace or unblocked flue can lose as much heat as leaving a window wide open
  5. Skirting boards on external walls — especially in homes with suspended timber floors and sub-floor vents
  6. Pet doors — uninsulated pet flaps can account for surprising heat loss overnight

Draught-Proofing Products & Costs

Door Seals

Product Best For Cost DIY Difficulty
Self-adhesive foam strip (V-seal) Door and window frames $5–$18/5m Very easy
Door bottom seal (brush type) Under exterior doors $15–$40 Easy — screw-on
Automatic door bottom (rises when open) High-traffic exterior doors $45–$120 Moderate — needs routing
Threshold seal strip Under door at floor level $20–$50 Easy — adhesive or screw
Draft snake / door sausage Internal doors in winter $8–$20 None — just place it

Window Seals

Product Best For Cost DIY Difficulty
Self-adhesive foam strip Hinged casement windows $5–$15/5m Very easy
Brush pile seal Sliding sash windows $8–$20/5m Easy
Silicone sealant (clear) Gaps around window frames $8–$16/tube Easy with caulking gun
Secondary glazing film Single-glazed windows $25–$60/window Moderate
Magnetic seals (timber sash) Double-hung sash windows $60–$150/window Moderate

Applying silicone sealant around a timber window frame — gaps between frames and brickwork are a maj
Applying silicone sealant around a timber window frame — gaps between frames and brickwork are a major draught entry point in older SE Melbourne homes, and a $10 tube of clear silicone seals them permanently.

Ceiling & Roof Penetrations

Penetration Type Fix Cost
Recessed downlights IC-rated covers from above in roof space $8–$15 each
Exhaust fan openings Self-closing flap kit or foam seal $15–$35
Ceiling hatch (uninsulated) Foam-backed insulated hatch cover $25–$60
Ducted heating/cooling grilles Draught-blocking grille covers (when off season) $10–$20 each
Plumbing and cable penetrations Expanding foam sealant $12–$18/can

Fireplace & Chimney

Situation Solution Cost
Unused fireplace (permanent) Block flue with rockwool batt + board $30–$80 DIY
Occasionally used fireplace Chimney balloon / draught stopper $40–$90
Gas log fire (no flue seal) Professional flue damper installation $150–$300
Open fireplace gaps Intumescent strip around surround $15–$30
Pro tip: A chimney balloon (also called a draught stopper) is an inflatable device inserted into the flue above the firebox opening. It blocks airflow completely when the fireplace is not in use, costs $45–$90, and is removable before lighting a fire. It’s the single most cost-effective draught fix for homes with unused or rarely used fireplaces.

Full Cost Estimate: Draught-Proofing a 3-Bedroom Melbourne Home

Area Products Needed Estimated Cost
3 external doors Door bottom seals + frame foam strips $80–$150
10 windows Foam/brush strips + silicone sealant $80–$180
6 downlights (ceiling) IC-rated covers + expanding foam $60–$100
2 exhaust fans Self-closing flap kits $30–$60
1 fireplace flue Chimney balloon $45–$90
Ceiling hatch Foam-backed cover $25–$60
Skirting and penetrations Expanding foam + silicone $30–$60
Total (DIY) $350–$700

Top 8 Tips and Gotchas

  1. Prioritise by draught intensity, not by ease. The chimney and ceiling penetrations are harder to access but lose far more heat than a window sill. Tackle the highest-loss points first.
  2. Don’t seal bathrooms and kitchen exhausts. Ventilation fans in wet areas must remain functional to prevent mould. Use self-closing flap units that seal when not running, not foam blocks.
  3. Foam strips compress and fail. Cheap open-cell foam draught strips deteriorate within 2–3 years in Melbourne’s temperature range. Spend slightly more on closed-cell EPDM foam or V-channel brush seals — they last 10+ years.
  4. Test before and after with an incense stick. Smoke from a lit incense stick held near suspected gaps clearly shows airflow. Do this on a cold, windy day for best results.
  5. The automatic door bottom seal is the best door fix. It rises when the door opens and drops to seal when closed. More expensive than a brush strip but eliminates the dragging problem on carpeted floors.
  6. Expanding foam is for permanent gaps only. Don’t foam anything you might need to open or access. Use it for pipe penetrations, cable entry points, and gaps behind skirting boards — not around operable windows or doors.
  7. Sub-floor is often the hidden draught problem. In homes with timber suspended floors over a vented sub-floor space, cold air infiltrates through the floor itself, not just walls. Underfloor insulation addresses this and is a separate project.
  8. Don’t over-seal to the point of poor air quality. A well-draught-proofed home needs controlled ventilation. Open a window briefly each morning to flush stale air, particularly in bedrooms. Very airtight homes can develop condensation and mould problems without adequate ventilation.
Safety warning: Never seal combustion air inlets for gas heaters or fireplaces. Gas appliances require fresh air for combustion — blocking their air supply can cause dangerous carbon monoxide build-up. If you have a gas wall furnace or open-flued gas heater, consult a licensed gasfitter before modifying the room’s draught-proofing.

Using an incense stick to detect draughts around a window frame — the smoke bends toward gaps, pinpo
Using an incense stick to detect draughts around a window frame — the smoke bends toward gaps, pinpointing exactly where cold air is infiltrating and where sealant or weatherstripping is needed.

Local Melbourne Resources

Frequently Asked Questions

How much can draught-proofing save on my energy bill?

In a typical Melbourne 3-bedroom home, comprehensive draught-proofing reduces heating and cooling bills by 15–25%. For a household spending $1,800/year on energy, that’s $270–$450 in annual savings. The materials cost $350–$700 for a full DIY job, giving a payback period of under 2 years. Combined with ceiling insulation, total energy savings can reach 40–50%.

Is draught-proofing something I can do myself?

Yes — most draught-proofing tasks are beginner-level DIY. Door seals, window foam strips, silicone sealant around frames, and chimney balloons all require only basic tools (a utility knife, caulking gun, and screwdriver). The main exception is ceiling penetration sealing, which requires working in the roof space and turning off ceiling lights beforehand.

What is the best draught seal for an exterior door in Melbourne?

For a high-traffic exterior door, the best combination is an automatic door bottom seal (which rises when the door opens and seals when closed) plus closed-cell EPDM foam or brush pile strip on the three frame sides. Automatic seals cost $45–$120 but outperform brush strips on carpeted floors and last 10+ years. For a low-traffic door, a screw-on brush strip bottom seal ($15–$40) is sufficient.

How do I stop draughts from my fireplace?

For an unused fireplace, a chimney balloon ($45–$90) is the most effective solution — it’s inflatable, fills the flue completely, and is removable before lighting a fire. For permanently blocked fireplaces, fill the flue with a rockwool batt and board over the opening with plasterboard. Never block an active gas fireplace or a heater with a flue without consulting a licensed gasfitter.

Can draught-proofing cause mould problems?

Over-sealing a home without adequate ventilation can increase indoor moisture levels and lead to condensation mould on cold surfaces. The solution is controlled ventilation rather than random draughts — open windows briefly each morning to exchange air, use exhaust fans in bathrooms and the kitchen, and consider a heat recovery ventilation (HRV) system for very airtight homes. A well-sealed but well-ventilated home is both energy-efficient and healthy.

Here’s the Bottom Line

Draught-proofing is the fastest-payback home improvement available to Melbourne homeowners — often paying back its cost within a single winter. The total materials outlay for a full DIY job on a 3-bedroom home is $350–$700, with annual energy savings of $270–$450.

Start with the four highest-impact fixes: door bottom seals, window frame foam strips, a chimney balloon, and ceiling hatch insulation. These four changes alone account for roughly 70% of the potential savings and can be completed in a single weekend for under $200.