newbie question re glazing

Hi all

I'm currently enquiring about having replacement timber frames and double glazing fitted. My current units are rotting pine-framed units with single glazing.
It appears that the glass is held in place with pieces of wood (are these beads?), pinned to the frame. This is on the outside of the frame though! It's a 2nd floor flat and this seems like a strange way of fixing the glass in to the frame. Surely if a pane of glass was ever broken and needed replacing, it would be much better (and safer!) to replace the glass whilst working inside the flat and not dangling about outside on ladders two stories high?

I am guessing that my over-simplified view must have some caveats? Is there a good reason why the glass is not fitted and held in from the inside?

Is there a good reason not to request that my new windows are designed in a way to allow glass replacement from inside the building?

Many thanks

Stu

I am an amateur DIYer so, others might be able to give you more information.
However,I understand that the current, or more modern method of fixing DG units either into timber or UPVC frames, is with the beading on the inside. I understand that this is an extra security measure so that the scoundrels cannot easily remove the panel when sizing up your property for a break-in. Even on a first or second floor installation, this seems to be the preferred method. I agree with your comment re any repairs being difficult from the outside and I think that you should insist on internal beading for a second floor installation.

As another DIYr...

If your glazier/window firm try & persuade you otherwise, show them the door & find someone else.
IMO It will be worth it in the long run to get internal beaded windows.

They are commonly available.

By the way, (someone "in the know" will no doubt comment) is this LABC notifiable?

traditionaly you would have putty finnishing off the windows as this allowed a waterproof barrier and a slope to shed the water
also a putty finnished edge is not realy very nice on te inside

thanks for the replies guys. So, with modern windows, I take it from what I can find on the 'net, they are fitted with glazing tape rather than putty? This means that they can be fitted from inside and not have an unattractive finish?
Any links where I can read up on the whole thing about fitting DG units to timber frames?
Thanks for your help. I'll post pictures when it's all done! (or falling apart around me and I have to call in the pros!)

Cheers

Stu