Is Mould Common in Portuguese Homes? What Expats Need to Know

Mould is one of the biggest fears expats have when buying property in Portugal — and for good reason.

Yes, mould is common in Portuguese homes, especially in older buildings and coastal areas. But the reasons may surprise you.

Why Mould Happens in Portugal

Portugal’s mild climate, combined with:

• limited insulation

• poor ventilation

• older construction methods

  
  

creates conditions where humidity builds up indoors, particularly during winter.

Many homes rely on opening windows rather than mechanical ventilation, which is often insufficient.

Why Expats Miss It During Viewings

• Viewings often happen in summer

• Fresh paint hides stains temporarily

• Furniture blocks problem areas

• Smell is masked by ventilation

  
  

Mould frequently appears after move-in, not before.

Why Mould Is More Than a Cosmetic Issue

Beyond appearance, mould affects:

• indoor air quality

• health (especially children)

• long-term property value

  
  

Treating it properly requires understanding the cause, not just cleaning the surface.

How Expats Can Protect Themselves

The safest approach is to:

• assess humidity and ventilation risks before buying

• avoid relying on cosmetic finishes

• understand what fixing is required long-term

  
  

Mould prevention starts before purchase — not after.