I need to toss some baseboards on some walls tommorow at work and am trying to figure out how much room I should leave under them for the carpet guy. I need to do put them on before the carpet as I will no longer be working there when the carpet gets installed. :D I am leaning toards a 3/8" or 1/2" gap cause the carpet is pretty thin and seems like it should stuff under that pretty easy. I have one area where i have a transition on the baseboards from hardwood to carpet. The hardwood flooring 5/8" if that makes a difference.

Are they going to put the tack boards under that carpet on the edges? That will jack up the carpet a bit, too.

I am facing the same dilemma in my basement, which I am remodeling right now. I'm also trying to run some satellite TV lines under the baseboards too...I'm probably going with 1/2" inch but I'm still deciding.

About 1/4" but no more than 3/8" so the carpet adge can be tucked under, but held tight
Tackstrip will go around paremeter of room, about 1/4" away from base moulding
The pad will obviously be cut to the tackstrip, so you don't allow space for it
Don't do gluedown carpet, use tackstrip and seperate padding

Can you a piece of the carpet,pad and tackboard, might help.
In reality, the best result would be to install the baseboard after the carpet is laid.

I laid a million yards of carpet with my grandfather foe Nebraska furniture Mart, and always baseboard was there, even new construction
You tuck the carpet in with a tool called a spreader, and in tight areas, a stair tool
The base mold holds it to the tackstrip

Than thats the way to do it, in production work, with cheap moulding

We worked for a large carpet dealer, and actually I remember replacing some a stick or two of some very expensive moulding, It got dinged while nailing the tackstrip. We wished you could put it last, but you need it to hold carpet down to tackstrip

It Can be done, my home (just sold) is 80 yrs old, all the baseboard is honduran mahogany (1x6).
Last time we had carpet installed they used tack strip without the pre installed nails.
Used an airgun to attach it rather than a hammer.
After using the kicker, they used a tool to tuck the carpet in that was made of a hard phenolic, took them alot longer to do, but we paid extra for it.

Raise the baseboards the thickness of the baseboard. 1/2" is way too high in my opinion. Essentially when the carpet is installed, the tack strip will be approximately a pinky finger thickness away from the baseboard. When the carpet is being installed the carpet will be held by the tackstrip and the installer just has to go around and tuck it in under the baseboard after trimming the excess.