As temperatures drop, condensation becomes a familiar issue in homes, offices and residential buildings across the UK. Those misty, water-coated windows might look harmless, but if left untreated, they can lead to damp, mould and costly damage.

Whether you manage an office, oversee a residential block or simply want to protect your home, understanding how condensation forms and how to control it is essential for maintaining healthy, clean spaces.

What Causes Condensation?

Condensation happens when warm, moist air meets a cooler surface such as a windowpane. The air releases moisture as tiny droplets, which gather on the glass and surrounding frames.

This is especially common in winter when indoor heating meets cold outdoor temperatures. Everyday activities like cooking, showering and even breathing add to the moisture levels inside a building.

According to the Energy Saving Trust, UK homes and workplaces can generate up to five litres of moisture a day through normal use – enough to cause problems if ventilation is poor.

Why Condensation is a Problem

While it may seem like a small annoyance, condensation can cause several long-term issues if ignored.

• Mould growth: Damp conditions encourage mould spores to grow on frames, walls and ceilings.

• Structural damage: Persistent moisture can weaken plaster, paint and wooden fittings.

• Poor air quality: Trapped moisture reduces indoor air quality and increases health risks for people with asthma or allergies.

• Unclean appearance: Windows with streaks and watermarks make spaces look poorly maintained, affecting both comfort and perception.

For managing agents or facilities teams, these effects can also lead to higher maintenance costs and complaints from tenants or employees.

How to Stop Condensation on Windows

There is no single solution to condensation. Instead, a combination of measures can prevent it and protect both interiors and windows.

Improve Ventilation

The simplest and most effective step is to let moisture escape.

• Open trickle vents or windows slightly, even in winter, to allow airflow.

• Use extractor fans in kitchens and bathrooms, ensuring they run long enough after use.

• Avoid blocking vents with blinds or furniture.

Good airflow reduces humidity, making condensation less likely to form on glass.

Maintain a Consistent Temperature

Sudden drops in temperature cause surfaces to cool faster, increasing the likelihood of condensation.

Keeping rooms evenly heated — even at a lower constant temperature — can help balance indoor conditions.

The Met Office recommends keeping indoor temperatures between 18°C and 21°C during colder months to minimise condensation and support comfort.

Reduce Moisture Production

Simple daily habits can make a big difference:

• Cover pans when cooking

• Dry clothes outdoors or use a vented dryer

• Keep bathroom doors closed when showering

• Avoid drying laundry on radiators

• Wipe away moisture as soon as it appears

These steps prevent excess humidity building up and spreading around the property.

Clean Windows Regularly

Regular cleaning helps identify and manage condensation before it causes damage. It also removes dust, dirt and spores that thrive in damp areas.

Using a professional window cleaning service ensures interior glazing stays clear and dry. In corporate buildings, interior glass cleaning complements external window services to maintain both appearance and hygiene.

For further guidance on maintaining clean glazing throughout the year, see our blog The Benefits Of Regular Office Window Cleaning.

Using Professional Support

Commercial and residential properties in London often require ongoing support to manage condensation. Building design, high occupancy and energy-efficient insulation can trap humidity.

Professional Window Cleaning

Professional cleaners can spot early signs of moisture damage and mould before they spread. At DOC Cleaning, our teams are trained to clean glazing safely and efficiently, including interior windows, frames and ledges that often hold moisture.

Specialist Maintenance Plans

For managed buildings, regular cleaning combined with periodic deep cleans and inspections reduces long-term risks. Facility managers can integrate these services into their maintenance schedule to avoid reactive costs later.

Products and Solutions that Help

There are several ways to manage indoor moisture and minimise condensation during winter. These practical tools can make a noticeable difference, but they should complement rather than replace professional cleaning and maintenance support.

Dehumidifiers

Dehumidifiers remove excess moisture from the air. For offices or residential blocks, they can be used in meeting rooms, washrooms or communal spaces where humidity builds quickly.

Portable electric dehumidifiers are effective, but passive versions such as silica gel boxes can also help in smaller spaces.

Anti-Condensation Paints and Coatings

For areas prone to damp or condensation, anti-condensation coatings create a barrier that helps surfaces resist moisture. These can be applied to walls near windows, reducing the chance of mould forming.

Window Treatments and Insulation

Double glazing, thermal blinds and insulated curtains help keep window surfaces warmer, reducing the temperature difference that causes condensation.

According to Historic England, even heritage buildings can benefit from discreet secondary glazing that balances comfort and preservation – an important consideration for older or listed offices.

When Condensation turns into Damp

Sometimes, condensation is a symptom of a deeper issue such as poor insulation or inadequate ventilation design.

If you notice:

• Persistent damp smells

• Black mould on window frames or corners

• Peeling paint or discoloured plaster

Then it may be time for a professional assessment. Early intervention prevents costly repairs and helps maintain a healthy environment for everyone.

Our teams regularly support property managers with post-clean inspections, helping them identify recurring moisture issues and recommend practical solutions.

Preventing Condensation in Offices and Shared Buildings

In offices or shared residential buildings, reducing condensation requires collaboration between cleaning providers, facilities teams and occupants.

For cleaning teams:

• Monitor moisture build-up during daily cleaning

• Wipe down window frames and sills

• Report signs of mould or leaks promptly

For property managers:

• Schedule regular inspections of ventilation and glazing

• Ensure heating systems are balanced and well maintained

• Provide tenants or employees with guidance on best practices

These actions maintain building health and reduce long-term maintenance costs.

Why Preventing Condensation Matters

Clean, dry windows improve light, appearance and overall wellbeing.

Beyond aesthetics, tackling condensation protects buildings and people. This is a key part of creating safe, comfortable spaces.

For corporate environments, clear glazing reflects care and professionalism. For residential buildings, it supports happier, healthier tenants.

Effective condensation control is both a cleaning challenge and an operational one, and it depends on teamwork, awareness and regular upkeep.

Get in Touch

We help offices, residential buildings and heritage sites stay cleaner and healthier throughout the year.

Our professional teams use sustainable products and expert methods to protect glass, reduce moisture and maintain the quality of every space.

Get in touch today to find out how we can help manage condensation, improve air quality and keep your windows clear this winter.