Erm, you might want to think again - Cornus alba has a few cultivars, most of which get at least 5 feet and some 10 or 12 feet. They also spread sideways, and the reddest stems are the newly produced ones, which means you will always have to cut down a third to half, or all, of the stems in spring to make sure you have red stems in winter. Cornus alba sibirica variegata is a bit shorter at around 5 five feet high, sometimes up to 6 or 7 feet, but Cornus alba elegantissima should be avoided - its a vigorous grower and gets easily 10 feet tall. I'm not sure these heights are appropriate for growing beneath a window...

Also, to look good they need to be kept well watered, and in full sun against the house's rain shadow you could well get crispy leaves.
The slower growing variegated ones can sulk in full sun too, I had some Hedgerows Gold that couldn't take the scorch in full sun but did well in mostly shade.
On the other hand, it's not an expensive plant so grab one for a fiver, see if it survives, and if it does then your pruning next March/April will provide lots of free hardwood cuttings for extra plants!

The red stems in winter are at their best morning and evening when the sun is at a low level and lights them up. So somewhere you can see it from the house in winter will give you more pleasure than having it under a window.Mine is shaded in the morning and gets the afternoon and evening sun and seems quite happy. I chop it to within about a foot of the ground in about April and in a season it grows to about 5 feet as Bamboo says. But in the summer its nothing much to look at as you can't see the stems because of the leaves.