It sounds like a better solution for you if it's just nearby.
When I saw the title I was all set to say "don't"! because I have 3 friends who use the local conservatoire and their DC have 1 or 2x lessons plus solfège (with lots of homework) as well as choir every month and then various "recitals" at the end of the year.
From what I hear, it depends on the teacher you get too - same as anywhere though!
We are putting off starting music lessons at the conservatoire because I don't want to have to drive to lessons 3x a week
The non-conservatoire lessons locally include solfège, so learnt along with the instrument, which seems better to me, but they are much more expensive, which is why we haven't taken the plunge yet.
DD's solfège is currently on Thursday at 5pm - she gets out of school at 4.30pm, we walk (slowly) to solfège, which is about 500m from school, and she is there for an hour. So by the time she is home it is 6.15pm. She is quite good at frontloading her homework so if she has something big for Friday, like memorising a poem or doing a reading comprehension, she doesn't have to do it on Thursday night. But I agree that an hour of solfège is quite demanding, so homework on top is a pain.
She's 8. So far for us the biggest problem for us is that the Solfege is on Monday and Thursday nights so what with having a bit of relaxation after school, travel time (approx 20 mins each way whether we walk or drive or take the bus), it's quite hard to squeeze in homework for the following day. She's the conscientous type and insists on doing it even though her teacher says she doesn't have to.
TBH, the logistics of DD's piano lesson (1.5 hours out of the house for half an hour's lesson, and an unpleasant journey and unpleasant area to hang around) are not really sustainable. I can do a year... and the spanking new conservatoire, literally 25m from our doorstep, looks awfully inviting. She could easily do three times a week if required.
DD started this year because she picked an instrument which can't be learnt anywhere else in our town. She has 2 x music theory and 1 times practical so we have to go there 3 times a week so it's quite a commitment. But the standard of teaching is excellent, the solfege is taught in a really fun way and because there is no waiting list for her instrument she got to start practical at the same time as theory. She doesn't have to join any groups until the third year by which time she will know if she wants to carry on with that instrument or not. Also there is a dedicated space so that dragged along siblings can do their homework which is handy.
I'm with Greythorne I think it does depend who runs conservatoire but I get the impression it's a very rigid french way of doing things which actually kills the fun and joy of music. My daughter has never done solfege except with her private piano teacher - she is with an ex japanese concert pianist who is fun and motivating and has a great level. I have never been near the conservatoire.
A brand, spanking new conservatoire is being built right next to where we live in Paris - it will provide a hugely expanded space for the teaching of music, drama etc in our arrondissement and is due to open for business next September.
Currently DD does weekly piano lessons (30 minutes) and music theory (1 hour in a small group) with a great teacher whom she loves, but (a) the logistics are difficult (b) it is very expensive. The conservatoire would be a lot more convenient and a lot cheaper. DD is quite keen on the piano and music generally and is quite persistent with activities, but I am worried about the work load at the conservatoire. Does anyone have any good information about this? I hear all sorts of horror stories from parents around me...