Why does my home feel so dry in winter, and is it doing any harm?

Recently reviewed·Reviewed June 2026, next review December 2026

Cold outdoor air holds very little water, so when it warms up indoors its relative humidity drops dramatically. A house with high air change in winter will often sit at thirty per cent humidity or lower, which dries skin, irritates throats and lifts dust. The fix is almost never a humidifier; it is usually reducing the ventilation rate to the level the house actually needs.

Editorial confidence: High confidence. Multiple regulator, government or academic sources agree.
Evidence status: Recently reviewed · reviewed June 2026 · next review December 2026
Monitoring: Every six months, plus whenever CIBSE comfort criteria for winter humidity are revised.

Evidence drawn fromBuilding standards: CIBSEProfessional bodies: EST

You may not need to read the rest of this page

You probably already have enough to act if:

Symptoms appear only during the heating season
A hygrometer confirms sustained RH below 30%
You have not yet adjusted ventilation or heating setpoint

Open the ventilation hub

This is probably the wrong page for you if:

Your home reads inside the 40-60% RH band already
Dryness occurs year round or in unheated spaces

Healthy winter indoor relative humidity

40-60% RH (action below 30%)

Source: Chartered Institution of Building Services Engineers · CIBSE Guide A treats 40-60% as the comfort and health band; sustained values below 30% are flagged as a comfort risk.

Who this advice is for

Applies to

Sustained winter indoor relative humidity below 30%
Centrally heated homes with high air-change rates in cold weather
Households reporting dry skin, static and sore throats only in heating season

Not intended for

Homes with year-round dryness unrelated to heating
Medical humidity prescriptions (which should be specified by a clinician)

What it usually looks like

These are the symptoms readers describe most often. None of them alone is diagnostic, but together they build a picture.

Dry skin and lips through the heating season
Static shocks on door handles and clothes
Wooden furniture creaks more in winter
Sore throat or dry eyes first thing in the morning

Most common in: Modern detached (post-2000) · Postwar semi (1945–1980) · Victorian terrace

Before you buy anything

Watch the house respond as you scroll.

These checks are listed in the order we would work through them. The illustration on the left changes with each one, so you can see what each check is actually addressing before deciding whether it is worth doing.

Warm wet air settles on the coldest surface and stays there. The window streams; mould follows.

Measure the actual relative humidity in occupied rooms

Anything between forty and sixty per cent is healthy. Below thirty needs attention. Knowing the number prevents over-correcting.

Look at whether you are over-ventilating

Extractors left running or trickle vents wide open in winter dump warm, moist air outside continuously. Tuning the schedule is free.

Check the flow temperature of the heating

Heating that runs at very high flow temperatures dries the air more than gentler systems. Lowering the flow temperature has a comfort benefit as well as an efficiency one.

Lower the thermostat by one degree as an experiment

Warmer air feels drier even at the same absolute moisture content. A modest reduction often resolves the perception without changing anything else.

Decide whether localised humidification is justified

Bedrooms and offices may benefit from a small evaporative humidifier. Whole-house humidification is rarely justified in the UK climate.

What we recommend, and why

Every recommendation explains why it comes first, the evidence behind it, how confident we are, and when it would not apply.

Tune ventilation before adding a humidifier

Why this comes first

Trickle vents wide open and extractors left running through winter dump warm moist air outside continuously. Tuning the ventilation schedule is free and frequently restores humidity into the comfort band without any equipment.

Evidence

EST and CIBSE both note that over-ventilation in cold weather is a common cause of low indoor humidity in well-heated UK homes.

EST · CIBSE

Confidence

High confidence. Multiple independent sources agree on the direction and the order.

Exceptions

Homes where ventilation has been deliberately increased to control damp

Next step

See the ventilation hub

Try a lower flow temperature or setpoint as an experiment

Why this comes first

Warmer air at the same absolute moisture content feels drier. A modest reduction in setpoint or flow temperature often resolves the perception without changing anything mechanical.

Evidence

CIBSE comfort guidance and EST heating-controls advice both link perceived dryness to elevated air temperatures rather than to moisture deficit.

CIBSE · EST

Confidence

Reasonable confidence.

Exceptions

Households where lowering temperature is not acceptable for comfort or health reasons

Next step

Open the heating controls hub

Real homes that faced this

Publicly documented UK projects that ran into the same problem and reported what happened.

We did not run these projects. Each links back to the original publisher so you can read the figures in context and judge for yourself what carries over to your home.

Evidence behind this page

Every recommendation on this page is traceable to its source. Click a publication to read the original.

Building standards
Used because these are the codified design standards UK building services engineers work to; they are written by the profession for the profession.
- Chartered Institution of Building Services Engineers
Professional bodies
Used because these organisations publish independent consumer and technical guidance rather than product marketing.
- Energy Saving Trust

Products that may help

Only consider these once the checks above have been ruled out. A product fitted into the wrong cause is rarely satisfying.

MVHR

House Summary

The cheapest answer to air uncomfortably dry in winter is usually the one that addresses the cause rather than the symptom. The list above is in the order we would work through it, because the checks at the top tend to rule out the most expensive mistakes further down.

Related decisions

Next Best Step

Ventilation; what your home actually needs

Take the next step