I hope someone there now can give you an update. But in case they don’t, I will share our experience from last September. I doubt it has changed much over the winter.
There were two places with ongoing construction, one at a building connected to the Sports Center (I think it is an old hotel they are renovating) but cannot recall the name. So there were some construction vehicles and materials near there. You will pass this spot walking between the train station and the Drei Berge on the “upper road” through the village. We did too but it did not bother us. Our apartment was right above the Sports Center so very close, but we heard no noise, even from our balcony.
Edit: I see wanderweg posted while was writing and has identified the hotel under construction as the Palace, which jogs my memory.
The other construction is at the Cablecar station where one connects from the car up from Gimmelwald to the one going up the Schilthorn. This is the line they are rebuilding. The Drei Berge is well above this lift station and I doubt you would hear any noise. The truck traffic was the main annoyance, especially walking down to Gimmelwald on the road. But there should not be any truck traffic on the upper road going to the Drei Berge.
There is also construction at the site of one of the towers holding up the cables on the Schilthorn Bahn. This sits right on the popular North Face trail and makes a short section of the trail muddy and hard to follow in spots. This site is probably where they were using helicopters to deliver supplies and tools, but we did not see any helicopters during our 6-night stay. I believe I would have been aware had there been any flying, as we find the process of delivering building materials and other items** by helicopter fascinating to watch.
** such as pallets of beer kegs going to a mountain hut, or an injured cow being brought down from the high meadows for treatment.
