BS 5250:2021

What is this BS 5250 - Management of moisture in buildings about? 

BS 5250 is applicable management of moisture in buildings. It details best practices for ensuring a code of practice for preventing moisture in buildings to minimizing risk to the users 

BS 5250 gives recommendations for the management of moisture in buildings using an integrated and pragmatic approach. It covers all states of water as gas, liquid and solid, and the interactions between these states. It describes the principal sources of moisture in buildings, its transportation and deposition and provides recommendations and guidance on how to manage those risks during the assessment, design, construction, and operation of buildings. 

Note: BS 5250 does not cover measures specifically dealing with flooding and escape of water. These are dealt with in BS 85500. 

Who is this BS 5250 - Management of moisture in buildings for?  

BS 5250 on the management of moisture in buildings is useful for designers, builders, and users of any class of building 

Why should you use this BS 5250 - Management of moisture in buildings?  

Moisture in buildings is a significant cause of many building failures, including some building-related occupant health problems.  

By adapting BS 5250 guidance designers, builders, and users can investigate risks of all sorts from high moisture levels, whether in the building fabric or in indoor air, which can endanger the health and well-being of building occupants and the integrity of the building. 

What’s changed since the last update?  

 BS 5250:2021 supersedes BS 5250:2011+A1:2016, which is withdrawn. 

BS 5250 is a full revision of the standard, and introduces the following principal changes: 

• Audience on moisture risk concerning problems other than just condensation has been added
• A whole-building approach to moisture safe design, introduced in the bsi white paper moisture in buildings [1] is adopted, including prescriptive, modelling and principles based 
• Approaches considering building context, coherence of design and detailing and interactions, capacity and in-service conditions have been added 
• A major revision of the content relating to floors (clause 10), walls (clause 11) and roofs (Clause 12) with particular emphasis on managing moisture risks in buildings undergoing Energy saving measures; and 
• A general update of other parts of the standard