I am planning a house with a walkout basement. Previously I put a room under the porch and topped it with hollow core concrete and poured the final concrete over that. Wanting to do similar but getting pushback from various people. Plans person says they have tried it before and AHJ would want the whole room to be insulated - the reason they gave was the top was exposed to the outdoor temperature. We will use it for storage and tornado shelter (and perhaps a wine cellar). When I called it a "safe room" AHJ stated it would have to be in compliance with ICC/NSSA-500. And the use of premanufactured concrete panels would require an ICC report or signed and sealed plans that show the construction was in accordance to ACI318. Not sure if that documentation is easily available but the use of 6" hollow core for a porch with 6' span is clearly overkill and much stronger than 4" poured in place that is acceptable to them. I stated it was impractical to meet all those requirements for a residential space and that perhaps I should have called it a "cellar". I then got this:
If the space is labeled as ‘Unfinished’ or as ‘Cellar’ then you would have to show that it meets the requirements of the 2009 IRC. The space would not inherently need insulation, but would need to meet minimum room size, electrical and ventilation.
Proposed room would be 6 x 28 (actually that's the outside of the foundation so room will be close to 5' x 26'). The alternative is to build the same room inside the basement - seems like duplication to build a slightly shallower room under the porch and fill it with gravel just to have another one inside the basement. This room will have a door into the rest of the walkout basement so the egress issue I think is met.
That may not be too hard to meet - does that just mean running a duct run in? What electrical is required? Just a light?
Minimum room size might be the main issue. It is about 130 sq ft so over the 120 minimum. But one dimension is less than 7' required for a "habitable room". But if it is cellar or unfinished I don't see why it would be considered habitable.
Anyone know specifically what sections of code might allow such a space or if a case could be made that this meets IRC2009 code (the version we are on)? If I have specific code to reference I may get some traction with the plans review.
If the space is labeled as ‘Unfinished’ or as ‘Cellar’ then you would have to show that it meets the requirements of the 2009 IRC. The space would not inherently need insulation, but would need to meet minimum room size, electrical and ventilation.
Proposed room would be 6 x 28 (actually that's the outside of the foundation so room will be close to 5' x 26'). The alternative is to build the same room inside the basement - seems like duplication to build a slightly shallower room under the porch and fill it with gravel just to have another one inside the basement. This room will have a door into the rest of the walkout basement so the egress issue I think is met.
That may not be too hard to meet - does that just mean running a duct run in? What electrical is required? Just a light?
Minimum room size might be the main issue. It is about 130 sq ft so over the 120 minimum. But one dimension is less than 7' required for a "habitable room". But if it is cellar or unfinished I don't see why it would be considered habitable.
Anyone know specifically what sections of code might allow such a space or if a case could be made that this meets IRC2009 code (the version we are on)? If I have specific code to reference I may get some traction with the plans review.
But does anyone have any specific references to the code for the size issue?
