I am planning to remove drywall ceiling and expose the beams. The area is above kitchen and family room. There are quite a few recessed lights and fans.
What considerations I have to bear in mind when I do this in terms of home value and sellability ?
You say the room is above the kitchen and family room. Does this mean the room is on the top flor? If so, you could be exposing attic insulation.
Beams used for concealed construction is often of a lower grade and may have large or missing knots, checks, etc.
Often roofing nails will penetrate the roof sheathing and you’ll need to cover the roof sheathing and nails. (When the drywall is removed, you’ll need to “deal” with the nail holes too.)
Of course you’ll need to reroute any electrical, heating ducts, drainage pipes, etc. Beams with holes drilled for electrical wires, etc. will need to be patched. Or, you’ll need to create a design scheme that is rustic so the holes don’t matter.
After considering all the above and other factors, I am inclined to say that this may not give expected return. The room is on first floor and their is second story above. Plus I will have to have do entire first floor. ( some of the points I did not mention in my question ). Ceiling joists are much closer than beams and it may not give same appealing look as beams ( which are spaced 4-5 feet or even longer). The joists which are currently concealed may not be appealing meaning more work to make them presentable. Most of the pictures I see for exposed beams are for vaulted ceiling - which is not the case here.
If it's done right, exposed anything is in fashion or trendy. It may not boost value but to some people it's all the rage. It's easy to re-sheet before a sale if it doesn't turn out well.
Why? There's likely just skinny ceiling / floor joists to see, and all the wiring for the lights & fan, and all the other stuff Lee Sam's answer mentions.
If you just want it to look like there's big thick wood beams on your ceiling that are 4 or 5 feet apart, you can just buy fake plastic ones and stick them up there.
They are surprisingly expensive though, Home Depot has a 4-3/8 in. x 2-1/4 in. x 13 ft. Modern Faux Wood Beam for $183.97 now, but does only weigh 7 pounds:
It would be a lot cheaper to buy a real 5x5 wood beam, cut it in half, and attach it to your ceiling, but the weight might be a problem. This wood weight calculator says a 6x6 by 12ft pine beam would weigh 91 pounds. But cut in half would help, and hollowing it out some would help too.
So another potentially cheaper idea is to use a 5 in. x 5 in. x 8-1/2 ft. Ashland Red Cedar Composite Fence End Post, it's currently $70.63 and weighs 31 lbs, but it might not look as good:
Sheetrock (plasterboard) is a good firebreak. Kitchens are quite a common place for fires to break out. If the space above the kitchen is habitable, you don't want to lose that firebreak.
In the UK, all ceilings (among other structural elements) must have 30 minutes fire-resistance. This is usually insured by using 12mm plasterboard. If you remove the plasterboard, you will have to provide the fire-resistance some other way. (Your property may not be affected by UK building regulations, but it is almost certainly affected by other, similar, regulations. Also, the fire risk exists even if there is no regulation.)
