Windows requirements

[jackart]

Hello,
Does NBC has any requirements on window size according to room type and area? There are requirements in Ontario Building Code but I can't find any in NBC and specifically in Manitoba Building Code. Does it mean that in theory windowless residential construction is legal? I'm not talking about egress from bedroom here. Thank you in advance.

 

[tmurray]

Hello,
Does NBC has any requirements on window size according to room type and area? There are requirements in Ontario Building Code but I can't find any in NBC and specifically in Manitoba Building Code. Does it mean that in theory windowless residential construction is legal? I'm not talking about egress from bedroom here. Thank you in advance.

The short answer is no.

Window sizes were removed from the code between the 95 and 05 versions when the code went to a performance based model. The only window sizes left were for egress windows in rooms intended for sleeping (bedrooms). Other windows did not satisfy any of the health or safety objectives of the code, so the provisions were dropped.

The OBC was based off older versions of the NBC, so it is this weird time capsule of provisions that have been amended or removed from the NBC.

 

[TheCommish]

dropping the windoe sizes except for EERO is very forward thinking

 

[Sifu]

Just curious about the NBC's performance provisions, the IRC has requirements for light and ventilation but has exceptions for mechanical/artificial alternates. Does the NBC have similar requirements?

 

[tmurray]

Just curious about the NBC's performance provisions, the IRC has requirements for light and ventilation but has exceptions for mechanical/artificial alternates. Does the NBC have similar requirements?

There is nothing for light. Due to climate, a mechanical ventilation system (HRV) is required by code to meet ventilation requirement. It can be avoided in seasonal dwelling units as they are much more likely to meet the fresh air requirements with only operable windows. Few people open their windows for fresh air in winter time here in the Great White North.

 

[jackart]

The short answer is no.

Window sizes were removed from the code between the 95 and 05 versions when the code went to a performance based model. The only window sizes left were for egress windows in rooms intended for sleeping (bedrooms). Other windows did not satisfy any of the health or safety objectives of the code, so the provisions were dropped.

The OBC was based off older versions of the NBC, so it is this weird time capsule of provisions that have been amended or removed from the NBC.

Thank you for comprehensive explanation.