# Minimum room size



## Rio (Jun 28, 2011)

We are designing some small bedrooms (for college students) in an existing house.  The client can't adjust  the footprint of the house.  For most of the bedrooms there is no size problem vis a vis approaching the minimun size of a room.  On the plans that I've attached there are two bedrooms with two slightly different layouts (still working out how they are going to go).  The bedrooms are over 100 s.f. however in each of them there is a stub wall that we are using as a shear wall due to the way the house is framed ( a strange addition done a long time ago).  My question is does having this stub wall (where the entry door to the bedroom butts against) create two rooms out of the one bedroom?  As it happens the walls end up being exactly half of the width of the room which for light and ventilation allow the rooms to be considered as one space (pretty sure that's right) and I'm hoping that this will also be the case for considering the space to be one and not two roomsPer CRC R304.2 "other habitable rooms shall have a floor area of not less than 70 square feet" but I can't find where it defines exactly what the definition of a room is with regard to this semi bifurcation of the space.Any clarification would be greatly appreciated.Thanks in advance,Rio

View attachment 1545


Minimum room size.pdf

Minimum room size.pdf


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## Jobsaver (Jun 28, 2011)

Of interest, at the stub wall, the minimum dimension requirement of 7 ft. in any horizontal dimension is not being met.


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## KZQuixote (Jun 28, 2011)

2009 IRC Section 303.2 Adjoining Rooms covers it. The bifurcation you've drawn does not define two rooms.

Bill


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## mark handler (Jun 28, 2011)

You are also not meeting "Natural light, ventilation, egress"


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## Rio (Jun 28, 2011)

Jobsaver said:
			
		

> Of interest, at the stub wall, the minimum dimension requirement of 7 ft. in any horizontal dimension is not being met.


 _R304.3 Minimum dimensions. Habitable rooms shall not be_

_less than 7 feet (2134 mm) in any horizontal dimension ._

Mmm, it looks like you have a good point.  If that's the case then we can't put closets in these rooms at all and will have to come up with another solution to deal with the lack of shear walls for the load coming down in that area.

Mark Handler wrote: "You are also not meeting "Natural light, ventilation, egress" "  Concerning this I think we are okay because the windows are casement windows and are 2' wide by 5' high, so they're plenty big for egress and ventilation and they're also over 8% for light (102 s.f. x .08 = 8.16 s.f.)    and as I thought and as pointed out by KZQuixote since the dividing wall is not more than 1/2 of the width the rear of the room can be considered as part of the room where the window is.

_ R310.1.2 Minimum opening height. The minimum net_

_clear opening height shall be 24 inches (610 mm)._

_R310.1.3 Minimum opening width. The minimum net_

_clear opening width shall be 20 inches (508 mm)._

It does appear that we are not meeting the minimum dimension rule however.............

Thanks a lot for the great information everyone,

Rio


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## KZQuixote (Jun 28, 2011)

Hi Folks,

If we all agree that they are each one room and the long dimension goes by the bifurcating wall the minimum dimension issue is moot. Other wise a seven foot by ten foot room with a two foot square closet would fail the test just because you could pull a dimension less than seven feet, in a two foot section of the room.

OK perhaps the closet area does not contribute to the square footage of the room. Let's assume that a bathroom has a stub wall that defines a five foot bath/shower combination, would you say that that room is five feet wide?

Bill


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## mark handler (Jun 29, 2011)

A 2 foot casement window does not have a net clear opening of 24 inches


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## Robert Ellenberg (Jun 29, 2011)

I have never seen the 7' requirement there before (which is the main reason I read this forum--to keep learning).

Bathrooms and closets are excluded if you go to the definition section and read Habitable space.  And perhaps the stub wall here is OK because the code doesn't say where you take the dimension and above the wall you would be OK.  However, I can't see how you get around it for any other situation.  I have built and been in lots of houses over the years with offsets in bedrooms; everything from a 36" offset coming into the room next to a closet to niches where you put desks or dressers.

Can any of you see a way to read this 7' requirement that allows such offsets?

Note--I think the intent is that the main part of the room (meeting the 70 SF requirement) could not be less than 7', i.e., you could have a 7'x10' room, a 8'x 8'9" room; but not a 6'6"x10'9".  But I can't read that in what is written and can even argue that if it were the intent, they would have written it like they write the sloped ceiling section where you can have space with a ceiling less than 5' in height but you don't get to count it.

Please chime in.


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## Jobsaver (Jun 29, 2011)

I interpret the code to say that once the minimum floor area having a minimum of 70 sq. ft., and, no horizontal dimension less than 7 ft, is established, what happens in the balance of the room is not important to the definition of "other habitable rooms".

Think of the minimum floor area more of as a required floor area.


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## Rio (Jun 30, 2011)

Jobsaver said:
			
		

> I interpret the code to say that once the minimum floor area having a minimum of 70 sq. ft., and, no horizontal dimension less than 7 ft, is established, what happens in the balance of the room is not important to the definition of "other habitable rooms".Think of the minimum floor area more as a required floor area.


This is the interpretation I'm going to go with.  Otherwise, in many cases, it would be too difficult to have a closet in a bedroom.

Regarding the comment on the 2' casement window not having a net clear opening of 24" it doesn't have to have a net clear opening of 24" in both dimensions, just the vertical one.  For the horizontal dimension it is required to have 20".  I'm going to double check the size of the window frame to make sure but we should be over 20" net clear width.

Thanks again everyone,

Rio


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## Papio Bldg Dept (Jun 30, 2011)

Rio said:
			
		

> This is the interpretation I'm going to go with.  Otherwise, in many cases, it would be too difficult to have a closet in a bedroom.Regarding the comment on the 2' casement window not having a net clear opening of 24" it doesn't have to have a net clear opening of 24" in both dimensions, just the vertical one.  For the horizontal dimension it is required to have 20".  I'm going to double check the size of the window frame to make sure but we should be over 20" net clear width.
> 
> Thanks again everyone,
> 
> Rio


I am in agreement with you on the 20" clear width, as you illustrated with Section R310.1.3.  I would however, verify that 20" when the casement is in the fully opened position, similar to how door clear widths are measured, and the window thickness encroaches into that clear width.  Four inches can disappear pretty quickly depending on the hinge point.


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## Jobsaver (Jun 30, 2011)

Several manufacturer's produce casements having sash that slide over as the window is cranked opened to provide full opening access. Special product lines include up to 22" clear widths on 2' windows.


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