21 Sept • Updated 3 Oct • Written By Jarred Nielson

Draught-Proofing a Tasmanian Home: The Cheapest Way to a Warmer Winter

Tasmanian winters are long, houses are often older, and heating usually runs on electricity. Unwanted air leaks around doors, windows, floors and other junctions can make rooms feel cold even while the heater is working. Reducing those leaks is often the cheapest comfort upgrade available, and it should usually come before a larger heating or solar spend.

This independent, engineering-led guide helps homeowners in Hobart and southern Tasmania find sensible starting points, choose suitable repairs and recognise jobs that need a trade or an assessment. The aim is a home with fewer uncontrolled draughts and reliable fresh air, not a home with every opening blocked.

Why draught-proofing is the first thing to fix (before heating or solar)

Draught-proofing limits unwanted air moving through gaps. Insulation slows heat moving through ceilings, walls and floors. A home can need both. Adding more ceiling insulation will not necessarily fix a gap around a ceiling hatch, and sealing floorboard gaps will not insulate the floor.

The Australian Government’s Your Home guide notes that air leaks can cause 15–25% of winter heat loss in buildings (CSIRO 2015). That is a general building figure, not a measured result for your house and not a promise to cut your electricity bill by 15–25%. Some households use less energy; others take part of the benefit as improved comfort.

A useful order of operations is:

building envelope first: draught-proofing and insulation;
then heating and hot water;
then solar and batteries, if they still make sense.

A larger heat pump or extra solar will still have to fight the same leaks if the envelope is left alone. For how that shows up on a bill, see Why your electricity bill jumps in a Tasmanian winter.

Why Tasmanian homes are especially draughty

Tasmania has Australia’s coldest climate and longest heating season. Many existing homes around Hobart are weatherboard or timber-framed, raised on stumps over a cold subfloor, with timber floors, ceiling hatches, and a mix of timber sash and later aluminium sliding windows. Exhaust fans that terminate in the roof space, unused fireplaces and wood heaters are also common.

Because so much winter heat is electric, every uncontrolled leak is money leaving the room. That is why a Tasmanian draught-proofing job is worth doing carefully: the comfort gain can be large, and so can the moisture risk if the house is tightened without working ventilation.

Before you start: check what must stay open

Do not block ventilation required for gas appliances, wood heaters, fireplaces or other combustion equipment. Some appliances draw combustion air from the room. Reducing that air supply, particularly while exhaust fans operate, can cause dangerous combustion gases to spill indoors. Tasmania’s building regulator has published hazard guidance on exhaust fans and flued appliances for that reason. Ask a licensed gasfitter about gas appliances and a suitably qualified solid-fuel specialist about wood heaters or fireplaces before changing their air supply.

Leave roof-space and subfloor ventilation, intentional fresh-air vents and drainage openings alone unless a qualified professional has assessed their purpose. Weep holes in brickwork are part of the wall’s moisture-management system, not gaps to fill with sealant.

Keep DIY checks to safely accessible areas. Do not enter roof spaces, remove electrical fittings or seal around hot flues as part of a simple draught hunt.

Do not automatically seal every internal door. Some gaps provide an air-transfer path for exhaust fans or heating. That matters around bathrooms and laundries: a fan that cannot draw replacement air will not extract moisture properly. Seal wet-room doors only when you understand how the room is ventilated.

How to find the draughts in your home

Choose a cool, breezy day. Close external doors and windows as you normally would, but leave required ventilation open. You do not need to run the heater specifically for this check.

Walk the rooms you use most:

look for daylight, damaged seals and rattling windows;
listen for whistling in wind;
feel with your hand or a lightweight tissue near a suspected gap;
watch whether curtains move when the window is closed.

Note the location, take a photo and check again in different weather if the result is unclear.

Do not use candles, lighters or incense, and do not deliberately depressurise the house by switching on every exhaust fan. A simple check is not a combustion-safety test.

A cold window is not necessarily a leaking window. Glass can lose heat even when the surrounding seals are sound. Air beside cold glass can also cool and sink, creating movement without an outdoor air leak. Look for evidence of leakage at the actual gap before deciding on a repair.

A blower-door test uses specialist equipment to measure building leakage under a controlled pressure difference. It is a separate diagnostic service, not something to assume is included in every home energy assessment.

Where draughts hide, and how to seal each one

Doors

Check the sides, top and bottom of external doors, including doors between the house and an attached garage. A door-bottom seal alone will not address gaps around the frame.

Measure the gaps and select weather strips designed for that door and threshold. Repair poor alignment or damaged hardware first. After fitting, check that the door opens, closes and latches normally. A door snake or draught excluder is a temporary draught stopper, not a complete perimeter seal. Keyhole covers can help on rarely used external doors.

Windows

Check both the opening sash and the fixed frame-to-wall junction. Compression seals often suit hinged windows; sliding and double-hung windows may need purpose-designed brush, pile or other compatible seals.

Match the seal to the window rather than forcing in the thickest tape available. Clean the surface as directed and confirm that the window still closes and locks. Keep drainage slots clear. Warped frames, failed hardware and decayed timber may need repair before sealing.

Pelmets and heavy lined curtains reduce heat loss through glass. That is a glazing-comfort measure, not a substitute for sealing the actual gap.

Chimneys and fireplaces

A fireplace that is no longer used may warrant a professionally assessed draught-reduction solution, such as a damper or chimney balloon, once it is confirmed that the flue is not needed by another appliance and that the approach will not trap moisture. Do not block an active flue or assume an unused fireplace can simply be filled with foam.

Vents and exhaust fans

Do not decide whether a wall vent is redundant from its appearance alone. Establish whether it serves combustion, room ventilation, the roof or the subfloor before considering a change.

An intermittent exhaust fan may leak air when switched off. A compatible backdraft damper or self-closing shutter can reduce this, but it must open properly when the fan runs. Combination fan, light and heater units need particular care: a generic cover may be unsuitable. If the home has an evaporative cooler, its roof outlets can also leak in winter and should be treated as a designed opening, not a gap to improvise over.

Exhaust moist air outdoors rather than into the roof cavity. A recirculating rangehood is not a substitute for exhausting cooking moisture outside. The fan also needs a path for replacement air. Where combustion appliances are present, changes to extraction and airtightness need a safety review.

Gaps, floors, hatches and fittings

Check floor-to-wall junctions, gaps between floorboards and openings around plumbing inside cupboards. These can connect the living space to a cold subfloor or wall cavity.

An appropriate flexible sealant or purpose-designed gap product may suit small gaps at skirting boards and architraves. Wider gaps or moving timber can need a different repair. Follow the product instructions rather than filling every opening with expanding foam.

A poorly fitting ceiling hatch can be an air-leakage point. A suitably fitted perimeter seal and insulation to the hatch may help, but safe access matters. Ceiling insulation and an air seal do different jobs.

Do not put tape, foam, insulation or improvised covers over downlights or electrical fittings. An LED label does not establish that a fitting can be covered. A licensed electrician should check the fitting’s rating, installation requirements and any replacement work. Refer gaps around flues, hot pipes or fire-rated construction to an appropriate professional.

What should you fix first?

Use this as a starting order, not a substitute for checking ventilation and safety:

Identify safety, ventilation and moisture issues. Understand which openings must remain functional.
Obvious gaps at external doors and windows, including door-bottom seals and weather strips.
Accessible floor, skirting and plumbing gaps, while preserving subfloor ventilation and drainage.
Ceiling hatches and exhaust systems, with safe access and the right trades.
Unexplained or extensive leakage. Investigate before widespread sealing or expensive window replacement.

A house with failed exhaust ventilation or a combustion concern needs that problem addressed first.

DIY vs calling a professional

Confident DIY usually includes measuring and fitting door and window seals, a temporary draught excluder, and sealing small accessible gaps with a compatible product.

Call a professional when the job involves gas or wood-heating air supply, electrical fittings, hot flues, roof or subfloor access, or a fireplace whose purpose is unclear. An independent assessment is useful when the home remains uncomfortable after obvious fixes, condensation persists, or you are comparing insulation, glazing, heating or solar upgrades and need a sequence, not a product list.

Tasman Energy Advisory does not sell draught-proofing kits, insulation or heating equipment, and accepts no commissions or referral payments.

The critical caveat: don’t over-seal

A less draughty home still needs to remove moisture from showering, cooking and clothes drying. Use externally ducted extraction, maintain it, and allow it to clear remaining moisture after the activity. There is no single timer setting for every home.

Ventilate deliberately. Investigate leaks or damp building materials rather than treating every moisture issue as a draught-proofing problem. Do not rely on permanently leaky windows to provide dependable fresh air. More extensive sealing may justify a planned mechanical ventilation approach.

After changes, watch for persistent window condensation, musty smells or stale bedrooms. Those signs call for a review of moisture sources, surface temperatures and ventilation, not more sealing by default.

How much will draught-proofing save?

Simple seals are a smaller commitment than major building upgrades, but a fixed price or payback period is not meaningful without a scope. Compare quoted costs with the improvement you actually need.

The 15–25% winter heat-loss figure is a useful national reference, not a household saving. Outcome depends on the leaks present, the work completed, heating efficiency, weather and how the household uses the home. Electricity bills also include uses unrelated to space heating.

Check current Tasmanian energy programs before assuming a rebate or loan will fund envelope work. Program rules change.

Your room-by-room checklist

Use this list to record what you have checked, not to certify that the house or its appliances are safe. Stop and obtain advice when the purpose of an opening is uncertain.

Check safely accessible external doors for damaged seals, visible gaps and door-bottom leaks.
Check window edges and frame junctions; keep drainage slots clear.
Note accessible gaps at skirting boards, floorboards and plumbing penetrations.
Identify wall vents and combustion appliances before proposing any sealing.
Arrange a safe inspection of suspect ceiling hatches or exhaust systems.
Confirm that changes will preserve fresh-air supply and moisture extraction.
Recheck operation, remaining draughts and condensation after the work.

Frequently asked questions

What does draught proofing mean?

Draught proofing is finding and sealing unwanted air leaks so a home is warmer and cheaper to heat. It is not the same as insulation, which slows heat through ceilings, walls and floors. In a Tasmanian home the aim is fewer uncontrolled draughts and reliable fresh air, not blocking every opening.

Is draught proofing worth it?

Often yes, as a low-cost first step. Australian Government guidance cites air leakage as a possible source of 15–25% of winter heat loss in buildings. That is not a promise to cut your electricity bill by 15–25%. The result depends on the leaks present, heating use and weather. Many households notice comfort first.

How do I draught-proof my home?

Check what must stay open first, including combustion air, weep holes and intended vents. Then look for obvious gaps at external doors and windows, followed by accessible floor, skirting and plumbing gaps. Fit compatible seals, keep exhaust fans working, and stop if the purpose of an opening is unclear.

How do I draught-proof windows?

Seal the opening sash and the frame-to-wall junction with products suited to that window: compression seals for hinged sashes, brush or pile seals for sliders. Keep drainage slots clear and confirm the window still closes and locks. Cold glass is not necessarily a leak; curtains and pelmets address heat loss through the glass.

What is the best filling for a draught excluder / door snake?

A door snake or draught stopper is a temporary door-bottom stop, not a complete perimeter seal. A dense, washable filling such as rice, sand or a commercial foam insert can work if the sausage stays in place. Repair alignment and fit a proper door-bottom seal and weather strips for a lasting fix.

Can you over-seal a house?

Yes. A tighter home still needs to remove moisture from showering, cooking and clothes drying. If exhaust ventilation and fresh-air paths do not keep up, condensation, damp and mould become more likely in Tasmania’s cold climate. Never block combustion air or assume old wall vents are redundant.

Should I draught-proof before installing heating or solar?

Usually yes. Reducing unwanted air leakage and improving insulation lowers the heat the system has to replace. Replacing a heater or adding solar first can leave the same leaks in place. Assess the building fabric, then heat and hot water, then generation, unless a failed appliance or safety issue comes first.

Do I need a professional, or can I DIY?

Most door and window seals, and small accessible gaps, are confident DIY if you leave required ventilation alone. Call a licensed gasfitter, electrician or solid-fuel specialist before changing combustion air, downlights or flues. An independent assessment helps when the home stays cold, condensation persists, or you are comparing larger upgrades.

Does a heat pump bring fresh air into the room?

Most standard split-system heat pumps recirculate indoor air rather than supplying outdoor air. Heating the room is not a substitute for ventilation. Check the actual system’s features if you are unsure. Pair a tighter envelope with working exhaust fans and deliberate fresh air, not with the assumption that the heater is ventilating.

Can I seal the old vents in my walls?

Not without establishing their purpose. Some wall vents serve combustion air, room ventilation, the roof or the subfloor. An older vent’s appearance does not prove that it is redundant. Have uncertain vents assessed before sealing, and do not treat weep holes in brickwork as gaps to fill.

Not sure where to start? Get an independent assessment

Tasman Energy Advisory provides independent home energy assessments for Tasmanian homeowners. We consider the building, heating, ventilation, hot water and electricity use together, then help you prioritise practical improvements for your home and budget. Thermal imaging may assist when conditions are suitable, but it shows surface-temperature patterns: it does not see through walls or independently measure whole-home airtightness.

No commissions or referral payments. Advice focused on your home.

Testing, access and specialist investigations depend on the agreed scope. A home energy assessment does not replace a gas-safety check, electrical inspection or detailed ventilation design.

Not sure where your home is leaking heat, or which fixes are worth it? Book an independent home energy assessment and get a prioritised plan, or explore what an assessment includes.