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Community and Q&A

Skylight vs. Window in Bathroom- Which is the Lesser of Two Evils.

spraggins | Posted in Energy Efficiency and Durability on

We are converting a narrow, long closet into a bathroom that will have a shower at the end which is an exterior wall (north exposure). As this will be the main bathroom for all the upstairs bedrooms, there is a high desire to have natural light. Our options are to either put a window in the shower or a skylight over it.

The window presents the problem of both sides needing to be water resistant. So I wonder, are both interior an exterior sills sloped along with the underlying pans and not sealed? Is there a back-dam dead center or none? For the interior, will the exterior tapes or fluid applied solutions be compatible with the shower systems (Schluter)? 

As for the skylight, well it’s a big hole in the roof and any penetration there makes me nervous, especially a retrofit one. Should there be special conditions to ensure the best waterproofing if we go this route instead. I feel confident in water proofing windows (at least on the exterior), but I’m not as familiar with the best practices on skylights. 

Putting aside the waterproofing durability concerns, I would imagine that the skylight is a less favorable option from an energy perspective as well.

So which route would you choose and what would you do to ensure the best durability and energy efficiency?

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  1. Expert Member
    DCcontrarian | | #1

    I'd say the window is the lesser of two evils.

  2. walta100 | | #2

    I have been pleased with the suntunnel in my guest bathrooms shower.


  3. johngfc | | #3

    I've had bathrooms with windows in the shower for many decades. They've not been a problem, even though there's condensation on the windows. They do require infrequent maintenance, which we do, and ventilation is important. A suntunnel (per Walta) with bathroom fan would seem a very good solution. If you don't do maintenance then I'd avoid the window option.

  4. oberon476 | | #4

    Also agree that a solar tube (sun tunnel) might be your best option.

  5. nynick | | #5

    There are youtube videos about waterproofing a window in a shower. It's not difficult to do. Just take your time and don't take any shortcuts during installation. Use a well insulated window with zero wood as part of it's construction.

  6. jollygreenshortguy | | #6

    Sun tunnels work great. But a window can certainly be made to work as well. Here's a link to a Fine Homebuilding article if you decide to go the window route. I would opt for a stone or acrylic (Corian) single piece sill as well.

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