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dormer as skylight?

MGMAN's picture

Anyone have a pic? I'm thinking about adding 2 dormers to my North facing single story, and treating them as a skylight, flanking each side of the covered front porch.

(post #83585, reply #1 of 17)

Not sure what you mean.

It is a skylight or it is a dormer, but both let light in and both can vent air out.

Skylight is cheaper, dormer looks better

 

 


Welcome to the
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Knowledge FHB Campus at Breaktime.
 where ...
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Oh Well,

We did the best we could...

(post #83585, reply #2 of 17)

It would be a standard dormer on the outside, but inside it would act as a skylight with a finished opening in the existing ceiling. The roof is a 5/12 pitch, and I'm trying to get an idea on how it would look inside. Could it be made to look good, or would it just look like a hole in the ceiling?

(post #83585, reply #3 of 17)

I'd say it'd work great if it's a cathedral ceiling. Otherwise, you're talking about a big box in the ceiling with a window up at the top.

Hmm. My magic 8-ball says 'Outcome uncertain.'

(post #83585, reply #6 of 17)

Or an eyebrow dormer which would have a pleasing profile.


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Edited 8/17/2008 1:03 pm by jagwah

 

 

(post #83585, reply #8 of 17)

(post #83585, reply #9 of 17)

Thanks, I was trying to simplify the larger pic I posted to this to help the dial uppers.

 


 

 

 

(post #83585, reply #4 of 17)

On a 5/12 roof the shaft would not be that tall if the front of the dormer was near the eave.

(post #83585, reply #5 of 17)

Quite frankly ... I think this is generally a GREAT idea! Why? I've always discouraged skylights in general (even though I have a skylight in my new home). Skylights are potentially problematic in that they are roof penetrations (everyone will jump all over this ... good flashing done right will produce 'no' problems and dormers are also roof penetrations (i.e. at the sidewalls). That is a small problem, though (IMO).


The big problem is energy ... if oriented wrong (e.g. south, east, west), they are losers big time. Gain WAY too much in summer and in winter they are usually always a loser. They often produce harsh light. Dormers, clerestories, etc. allow you to control energy and light in much better ways. Provide eaves to protect from the summer sun, allow winter sun it, and control the light better.


Personally I think they tend to look better, too. There is a time and place for everything, though. You MAY have to use tempered glass ... not sure about this. Check w/ the BO. ... maybe someone knows about this. Skylights need to be tempered glass, but not sure about high dormers/clerestories.


What is your orientation of these proposed dormers? Glass choice may be important if you e.g. face west.

There ain't NO free lunch. Not no how, not no where!

(post #83585, reply #7 of 17)

As part of the front "facelift", the existing porch will be replaced with a larger structure that includes some lattice detail, and different columns, and the dormers would flank that on each side.

(post #83585, reply #10 of 17)

Now the focus is on design, proportion, etc. This can be crucial to the resulting overall look. The dormers can't dominate the elevation. You have a small house profile so larger dormers may not work visually. Do plenty of drawings/sketches to get the feel for how it will look. Will you use shed or gable dormers? You might consider each (even w/ the gable entry style). Shed dormers may have the low profile you need (and they provide a little better sun protection).


Also looks to me like a west facing entry (?) ... I'd use low SHGC glass! Under 0.30 ... depends on your location, too, though, but west facing in most locations is a bad thing. If you have warm summers ... go lower 0.20 or under.

There ain't NO free lunch. Not no how, not no where!

(post #83585, reply #11 of 17)

MGMAN


  I've got 11 dormers as skylights,  go to 85891.1 for a few examples.. my dormers face north, south, east,  and west. 


 So amount of light varies depending on the time of day but they  don't  do  one thing that sky lights do.  They  don't leak!

(post #83585, reply #12 of 17)

frenchy, do you have a specific picture of a dormer above a flat 8' ceiling? Just trying to get a visual on it.

(post #83585, reply #13 of 17)

I've done it several times. Depending on the proportion of the "box" to the room underneath it can take on the feeling of a double height space. The quality of light and shadows is more complex than that usually provided by skylights.

(post #83585, reply #14 of 17)

any pics?

(post #83585, reply #17 of 17)

No pics. The abbreviated version of a long story is that I sold it unfinished to the provincial government, who converted it into a group home. The only person I know who has been near it since was my partner's son who went trick or treating there one Halloween, and was chased down the driveway by one of the special needs residents.


A couple of things to consider. The flat dormer ceiling can continue as deep as you want into the room. Think about lighting not only from the perspective of the room but also the exterior. The dormer well lit from within looks great from the street. Also consider making the window operable and perhaps installing a ceiling fan. It is a good way to exhaust warm air in the summer.

(post #83585, reply #15 of 17)

couple of things are noticeable to be concerned with here. One is that your existing roof is not tall, so that limits how much of a dormer you can do. That eyebrow photo looks good but I doubt that it would work with the way I pervieve your interior, and twin competing eyebrows would not work IMO. Doghouse dormers are more common to a cape style with a steeper, taller roof.

the other problem I am imagining is that to do this, you would have to cut out one rafter or two for each of these and double up the flanking ones. That brings to mind the Q whether you have rafters or trusses.

I had first pictured what you describe as in a cathedral type ceiling, but it sounds like you clarified that it is normal flat so you would have to frame a chute. As Grant mentioned, that much would be better from the interior perspective with your low pitch, but the window size would be limited by the low dormer height.

Somebody with 3D cad could model this up for you to let you see what it would look like on your house, instead of you trying to imagine it from photos in somebody elses house. CAD also helps you with things like tracking light and shadow as the sun moves across the sky, but if this faces north, that would be less important.

Another issue will be maintaining quality insulation, VB, and ventilation systems as you penetrate those bariers.

 

 


Welcome to the
Taunton University of
Knowledge FHB Campus at Breaktime.
 where ...
Excellence is its own reward!

 

 

Oh Well,

We did the best we could...

(post #83585, reply #16 of 17)

We built one with the light shaft / dormer directly over the front entrance, washing free light into the foyer.  Really worked out great.  We installed a switched duplex outlet for the inevitable Christmas candle in the dormer window.  The second dormer lights the attic, but we put a frosted fan window high in the den wall (at the end of the cathedral ceiling)


I'll try to get some photos.


Greg