# Trying to design a lanai / veranda over a basement space



## glentner (Mar 30, 2016)

I'm in the process of designing my house. I want to have an open "porch area" on the back of the house on the main floor.  The main floor is about 5 feet above grade and I don't want it to hang out like a deck.  So my solution was to make it like a lanai or veranda and have it be incorporated into the main level - just like another room.

Someone told me that they weren't sure if you were allowed to have an un-conditioned, open air room above a basement in Ohio.  The lanai would be completely covered with a ceiling and roof. I'm guessing that the floor would be ceramic or similar.

Does anybody have any experience or information on designing something like this?

Any help if greatly appreciated.

-Greg


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## cda (Mar 30, 2016)

Welcome

You do know lanai's are only allowed in Hawaii.


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## cda (Mar 30, 2016)

Ok you want to put the lanai on top of the basement

my bad


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## JBI (Mar 30, 2016)

glentner (Glen), First, welcome to the forum.

I believe that if the entire basement were 'unconditioned' space it would not be a problem.

Similarly, if the main basement is within the thermal envelope but the area beneath the open porch were 'thermally isolated' that should be compliant as well.

Either way the unconditioned basement below the open porch would make an excellent wine room...


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## glentner (Mar 30, 2016)

Yes, the lanai on top of the basement.  So the basement would be a normal conditioned space.  I am hoping that the "lanai room" upstairs  wouldn't have to be a separate room downstairs.

As long as the ceiling in the basement under the lanai is insulated, I feel like it shouldn't be a problem? (but what do i know).


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## cda (Mar 30, 2016)

Not a house person,,

But is it much different than a garage on top of a basement

Call to the building dept that would review and ask the question,,, this is free

Not sure if any of this helps::

http://publicecodes.cyberregs.com/ic..._11_sec002.htm


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## JBI (Mar 30, 2016)

> Not a house person,,But is it much different than a garage on top of a basement
> 
> Call to the building dept that would review this is free
> 
> ...


Most of my work has been with residential... not much different than a garage above a basement, though frankly not commonplace in NYS.

Essentially the basement ceiling beneath the lanai becomes the lid of the thermal envelope, so may require more insulation.

For example, NYS is mainly Climate Zones 5 and 6 (little bit of 4), so the lid needs R49 prescriptively, as the bottom of the envelope it drops to R30 or less.


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## steveray (Mar 31, 2016)

Or you could insulate a wall in the basement that would separate conditioned from not...As long as the "box" is complete, how you get there is up to you...


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## glentner (Mar 31, 2016)

I am right in the middle of zone 5.  I am hoping that simply insulating the basement ceiling under the lanai will do the trick too.

Thanks for the help.


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## JBI (Mar 31, 2016)

It should do the trick, but treat it as the top of the envelope rather than the bottom. Depending on location (State) and year edition of the Code, the R-49 may get the allowable reduction to R-38 if the insulation is full depth at the outside edges. That should be no problem since floors don't slope like rafters do. With the basement walls it is often beneficial to place the bulk of the insulation on the outside of the walls which allows a slight reduction in R-value as well. (The mass wall will absorb warmth during the day and release it slowly into the basement space at night)


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## Builder Bob (Apr 6, 2016)

The local building department may require a design professional since this design makes the brace "shear"  wall installation of the code "irregular".... if the engineer designs it correctly, i say go for it...


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## JBI (Apr 7, 2016)

> The local building department may require a design professional since this design makes the brace "shear" wall installation of the code "irregular".... if the engineer designs it correctly' date=' i say go for it...[/quote']B Bob - First of all, there are no braced walls above as a lanai is essentially an open structure.
> 
> Second, even if viewed as a braced structure above, the methods for prescriptive wall bracing allow this to be treated as 2 'boxes' so to speak, with each box having the required bracing.


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