You're wiping condensation off the windows every single morning. You can feel the draught by the front door but can't work out exactly where it's coming from. Certain rooms are freezing no matter how high you turn the heating. And there's black mould creeping back in that corner you scrubbed clean two months ago.

These aren't separate problems - they're all connected. Your home is losing heat through gaps and poor windows, but it also isn't ventilating properly. Seal everything up without proper ventilation and you'll trap moisture inside, making damp and mould worse. Leave draughts whilst adding ventilation and you're still wasting heat.

Getting this balance right - airtight where you want it, ventilated where you need it - makes your home more comfortable, cheaper to heat, and healthier to live in.

Here's what you need to know.

The Three Things You're Actually Dealing With

Draughts - uncontrolled air leaks through gaps around windows, doors, floors, and where services enter your home. You're paying to heat air that immediately escapes.

Windows and doors - old single glazing or failed double glazing loses heat and creates cold surfaces where moisture condenses. Modern windows and doors are properly insulated and sealed.

Ventilation - controlled airflow that removes moisture, stale air, and pollutants. This is intentional, necessary, and completely different from draughts.

Some people try to fix draughts and windows without thinking about ventilation. That's when problems with condensation, damp, and mould get worse instead of better.

Why Getting This Wrong Creates Bigger Problems

Your home generates moisture constantly - cooking, showering, breathing, drying clothes. In a typical home, you're producing 10-15 litres of moisture every day. That moisture needs somewhere to go.

Old leaky homes "breathe" through gaps and cracks - unintentional ventilation via draughts. Not efficient, but the moisture escapes alongside the heat. It's wasteful but it works.

Here's what happens when you fix one problem without addressing the other:

A customer came to us having had new double glazing and draught-proofing done on their Victorian terrace. Made perfect sense - the place was freezing and the heating bills were ridiculous. Within three months, they had black mould spreading across their bedroom wall behind the wardrobe.

The problem? Their old leaky windows and draughty doors had been removing moisture without them realising it. Seal everything up without adding proper ventilation and that moisture has nowhere to go. It condenses on the coldest surfaces - typically external walls, corners, and behind furniture - and mould grows.

They ended up paying for mould treatment, redecorating, and installing mechanical ventilation. Cost more than the windows did, and they had to move furniture out whilst it was sorted.

This is why draught-proofing and ventilation must be addressed together. Seal the uncontrolled leaks, add controlled ventilation where you need it. Get the balance right and you're comfortable, efficient, and healthy.

Understanding What "Balance" Actually Means

The goal isn't making your home completely sealed or completely open - it's being airtight in the right places and ventilated in the right places.

Airtight where you don't want air movement:

• Around window and door frames

• Where pipes and cables penetrate external walls

• Between floorboards and external walls

• Around loft hatches

• Through unused chimneys

Ventilated where you need air movement:

• Kitchens and bathrooms (moisture at source)

• Background ventilation throughout (trickle vents, controlled systems)

• Underfloor spaces (airbricks must stay clear)

The difference is control. Draughts are uncontrolled - they happen wherever there's a gap, wasting heat constantly. Ventilation is controlled - it happens where and when you need it, removing moisture without wasting loads of heat.

Modern homes achieve this through properly sealed windows and doors (with trickle vents for background ventilation), powerful extractors in wet rooms, sealed gaps and penetrations, and sometimes whole-house ventilation systems that recover heat from outgoing air.

Your home feels warmer because you're not losing heat through gaps. Your bills drop because you're not constantly replacing heated air. And you don't get condensation or mould because moisture is being removed in a controlled way.

How to Get the Balance Right

Once you understand the balance, here are the practical improvements that address it.

Replacing Old Windows and Doors

If you have single glazing or old double glazing that's failed (misting between panes, visible gaps, frames that rattle), replacing them transforms both comfort and efficiency.

Modern double or triple glazing includes insulated glass units that keep internal surfaces warm (no condensation), properly sealed frames (no draughts), and trickle vents built in for background ventilation without draughts.

The difference is immediate. Rooms feel warmer, condensation disappears, external noise drops significantly. You're not constantly wiping windows or feeling cold air around frames.

Modern external doors work the same way - insulated, sealed, no gap at the bottom where draughts used to pour through.

Cost:

• Double glazing: £400-£800 per window

• Full house (10-12 windows): £5,000-£10,000

• External doors: £800-£2,000 per door

If your windows are single-glazed or obviously failed double glazing, this is usually the most impactful upgrade you can make. The comfort improvement alone justifies it for most people.

If you're planning insulation work, coordinate windows at the same time - scaffolding's already up and you ensure everything works together as a system.

Sorting Ventilation Properly

How much ventilation you need depends on how airtight your home is becoming and how much moisture you generate.

Kitchen and bathroom extractors are the minimum. Powerful, properly specified extractors remove moisture at source before it spreads through your home. If you're sealing draughts or replacing windows, making sure these are working effectively becomes crucial.

Many older extractors are undersized, incorrectly positioned, or barely functional. Upgrading to modern extractors that respond automatically to moisture levels means they run when needed - after showers, during cooking - then reduce airflow when moisture drops.

Cost: £150-£400 each installed

Whole-house ventilation systems suit homes that are becoming very airtight - typically after comprehensive insulation, new windows, and air sealing work.

MVHR (Mechanical Ventilation with Heat Recovery) provides continuous fresh air whilst recovering about 90% of the heat from outgoing air. Fresh air comes in, stale moist air goes out, but the heat stays in your home.

This makes sense when you're doing comprehensive insulation and airtightness work, you want consistently fresh air without opening windows, or you have or are getting a heat pump (they work better in airtight homes).

It doesn't make sense for most homes doing basic draught-proofing - you'd be spending £4k-£8k on something you don't need yet.

Cost: £4,000-£8,000 installed

For most homes, effective bathroom and kitchen extractors plus trickle vents on windows handle ventilation needs perfectly well. MVHR only becomes necessary once your home is properly airtight.

Sealing Air Leaks

If you're doing insulation work or major improvements, addressing air leakage properly makes everything else work better.

This means sealing gaps where pipes, cables, and services penetrate external walls, around new window and door frames (proper installation, not just foam), floor-to-wall junctions on external walls, loft hatches, and unused chimneys (sealed but vented to prevent damp).

Done properly, this makes your home noticeably warmer - no more mysterious draughts you could never quite locate. Your heating system doesn't work as hard because it's not constantly replacing air you've just paid to heat.

This isn't something you'd typically do as standalone work - it happens alongside insulation, window replacement, or renovation. Once walls are open or scaffolding's up, addressing air leakage properly just makes sense.

Cost: Usually included in insulation projects, or £500-£1,500 as standalone work

What It Actually Costs

Basic draught-proofing and ventilation upgrade:

• Upgrading kitchen/bathroom extractors: £300-£800

• Trickle vents on existing windows: £50-£100 per window

• Basic draught-proofing materials (DIY): £50-£150

Total: £500-£1,500
Makes sense if windows are reasonable but ventilation is poor.

Window replacement with proper ventilation:

• New double glazing (10-12 windows with trickle vents): £5,000-£10,000

• Upgraded extractors: £300-£800

• External doors: £800-£2,000

Total: £6,000-£13,000
Makes sense if windows are single-glazed or failed, this solves both heat loss and provides proper ventilation infrastructure.

Comprehensive approach (with insulation):

• Insulation (loft, walls, floors): £5,000-£20,000

• Windows and doors: £6,000-£12,000

• Air sealing: Usually included

• MVHR system: £4,000-£8,000

Total: £15,000-£35,000

Makes sense when doing major insulation work - addressing airtightness and ventilation together means everything works as a system.

The right investment depends on where you're starting from and what else you're doing to the house.

DIY Draught-Proofing: What You Can Do Yourself

You can tackle basic draught-proofing yourself - door excluders, foam strips around windows, sealing obvious gaps around pipes. Materials cost £50-£150 and make an immediate difference to comfort.

It's a good temporary measure if windows and proper work are a year or two away. Every gap you seal reduces wasted heat.

But be mindful of ventilation. If you're sealing up gaps, keep trickle vents on windows open (they're there for a reason), don't block airbricks (they provide essential underfloor ventilation), ensure bathroom and kitchen extractor fans are working, and open windows regularly, especially after cooking or showering.

DIY draught-proofing is fine for reducing obvious draughts. But if you're planning comprehensive improvements - new windows, insulation, proper air sealing - that needs professional assessment to avoid creating condensation problems.

The difference: stuffing foam in gaps stops draughts but might trap moisture. Professional work seals the envelope properly whilst ensuring controlled ventilation where you need it.

What Your Home Actually Needs

The right approach depends on what you have now and what else you're planning:

Single glazing or failed double glazing? Windows are the priority - they solve heat loss and condensation in one go. Make sure extractors are working when you do this.

Decent windows but condensation problems? Ventilation is the issue - upgrade your extractors and ensure trickle vents are open.

Planning insulation work? Address windows, airtightness, and ventilation together. Everything works as a system and you only disrupt the house once.

Planning a heat pump? Sort windows and ventilation first - heat pumps work more efficiently in airtight homes with proper controlled ventilation.

Getting windows, doors, ventilation, and airtightness right isn't just about buying better products - it's about understanding how they work as a system in your specific home. A proper assessment looks at where heat's being lost, where moisture is a problem, and what ventilation you currently have, then recommends the right combination that gives you the balance you need.

The result: a home that's comfortable, efficient, and doesn't have condensation or mould problems. No more wiping windows. No more mysterious draughts. Just even warmth and fresh air without the waste.

Planning windows, doors, and ventilation as part of your home improvements? We help you work out what combination makes sense for your home and how it fits with insulation and other upgrades - getting the balance right so you're comfortable and healthy. See how Furbnow works.