Rotting windows on period house

[Stu82]

Hi. I've just bought a 1920's house in need of restoration. It has large hardwood bay windows which look a mess. On inspection I found that the upstairs bay window sills have been covered in lead which has been nailed Down across the whole sill. I didn't pull up the lead but it felt solid enough underneath. The end of the sill wasn't covered and felt a little soft.
Most of the rest of the frames were solid even though the paint is coming off and bare wood is showing, although on the front upright ( not sure what I call it) it looks like the outer surface of the wood is spitting but doesn't look structural

There is also a tudor effect which has some wet rot.

Who do I need to fix this? Carpenter, general builder or glazer?
I would prefer not to replace the whole thing with pvc as they are a nice feature and there is no rot at all on the lower frames. Is it a big job to replace the sills entirely?

Thanks,

 

[HERTS P&D]

Do a key test, this is done by pushing your car or door key into the timber, if you can do this then you need new windows. As the timber is rotten.

Andy

 

[maltaron]

Upvc is not mandatory. A good joiner will make new wooden windows or repair the existing. It is often enough to fit new cills and splice the mullions, and possibly new sashes.

 

[Stu82]

Thanks for the responses
I think I will try and go down your line maltaron, although they are casement rather than sash (I dont suppose this makes a difference) however I have a concern about the noise. A double glazer has suggested to me that we fix up the frames and put double glazing panels into the existing wood. Anyone have experience with this? I would rather not be a guinea pig

Also, will I get less road noise through UPVC than wood even though both would be double glazed? I wouldn't want to go to the trouble of installing double glazing panes in old frames then find they are still too loud.

Thanks,