Extend lounge or add a room??

[pinkpip100]

We currently have a rickety old lean-to and outbuilding (used to be an outside toilet I think) attached to the back of our house. Both areas are just a dumping ground at the mo and we'd like to do something more useful with the space. We've had a couple of builders round; one suggested knocking through from the lounge to the back area and building a brick extension on the existing lean-to/outhouse footprint. The other suggested creating a separate back room/conservatory (with glazed roof and full-length glazed back wall with sliding doors to the garden, but brick side walls, if that makes sense?). I'm torn... love the idea of the more open-plan option (knocking through to create a nice big lounge) but am wondering if I'll wish we had a totally separate space once the kids are older (they're now nearly 5, 3 and 9 months. DH is also unsure. Any thoughts?
Also, if we went for the glazed option, great for letting light in but would it get unbearably hot in the summer? It would be south-west facing...

We seem to be going round in circles here so any tips for how to make our mind up would be great

We have a seperate conservatory as a play room and I LOVE having a seperate room for all the kids clutter, nad a seperate 'grown up' room for us. Not having to stare at great lumps of primary coloured plastic every evening is a joy!

I have two downstairs rooms - i love the fact that we can all have a bit of space without being in a bedroom.

Also when dd has boy friend around then they can go in one room and have a bit of privacy without feeling like they are being watched or having to go upstiars to get away.

both dd's are in one room atm watching drity dancing and I am in here having a sneaky chocolate mouse - last one in the fridge

separate room. at some point someone is going to want to shut a door.

Another vote for a separate room here.We have a large lounge diner,but I'd love somewhere separate,so that when my friends come around,dh doesn't have to go upstairs or to the pub if he doesn't want to listen to us all gassing on.

Gosh, its looking fairly weighted towards a separate room so far! Thanks for your replies, I think because my dcs are still so young its very hard to think about what they'll need (and what we'll need!) as they get older.

Ivykaty, I definitely like the idea of a space for the dcs to spend time in when they're older and have friends round rather than sitting up in their rooms. Especially important I guess as ds1 and ds2 share a bedroom.

Jojay I have to say I'm always a bit envious of my friends' houses with playrooms that they can shut the doors at the end of the day whilst our lounge is still full of the kids clutter. I've always put it down to our lounge being too small though, so thought maybe a bigger space plus plenty of toy storage might have the same effect.

We do have a large-ish kitchen diner that we will happily sit in - which is where my friends and I tend to drink wine socialise if dh is in the lounge.

Hmmm. And any thoughts on the conservatory vs brick built options?

A conservatory may well get too hot in the summer. Ours is north facing and it works well as htey are generally easier to heat than cool down.

Have any of your neighbours got a conservatory? Could you ask them?

Thanks Jojay. No, no neighbours with conservatories, possibly because of the south facing gardens!