To ask for advice about right to privacy from our neighbours

Report them asap. The garden room and lack of privacy may also affect the value of your house.

Periods FFS.

Sorry 12 but loads of girls have errors at that age.

And yes, having been sexually harassed from 11 I know teenage boys. As does DD from 11 as well.

Mums of boys, please be aware.

In what world is a 13 yo prepubescent?

all the teenage boys i know would rip the absolute shit out of anyone looking through a 12yo’s window… obviously does depend on whether boys are 13 or 17 though! can’t imagine too many going to look at a prepubescent girl though

I just mean it would be very difficult living next door to people you have 'reported' to the authorities. Whether you win or lose, they might get unpleasant.

Then you are deluded....

Check with the Council about permission. Even if they have 'Permitted Development' the Terms should stipulate that the building doesn't overlook private/personal space or causes distress. Once you have the info go speak with the neighbour explaining your concerns & ask if they can either heighten their fences, put up blinds or anything else you can think of to minimise their view of your Daughters bedroom. Try & keep calm & if they become unreasonable say you'll speak with the council/planning department asking them to come & view the building & see what they say. If they haven't got permission then they may well not want any hassle & help you resolve the situation.

I’m presuming this post refers to neighbourly relations.

Knowing terraced back yards, from the two people I’ve known live in this type of house, there is usually zero privacy anyway and I’d be trying to think of ways to install fencing, privacy blinds etc I would have done this before this garden room was installed as surely, as they’re higher up, they would have been able to look directly into the yard/window anyway?

In what way would they be in a right mess? Do you mean in way that ruins neighbourly relations or do you mean legally?

Whether it's legal or not, you will be in a right mess if you complain to the authorities and they are forced to take it down. The ideal thing would be one way glass but that's pretty expensive. The sticky-on stuff is almost as good except when the lights are on. Making the fence higher is obviously an option but there again it's notcheap.

a 12 year old girl’s? very much doubt it

As I have said - several times- I am talking about permitted development rights. Because the issue was did the building/extension require PP.
As I have also said, other legislation and regulations will have other rules. But that will not stop something being permitted development under the planning legislation.

Ps
Of course I forgot to mention the fire hazard issue too if it’s less than 1m 😳

Appreciate you have experience.
Likewise as an architect.
You can’t put a window looking straight into a habitable room. See my post ie on a boundary ( 1m back you are probably ok as you can block it with a fence - see my post ).

Nothing is just as simple as saying you are allowed an overlooking window at ground floor, It’s not that simple.

( She’s a terrace, so the properties will be very close )

Permitted development doesn’t give people the right to run amoch and ignore others rights.

Do you know any teenage boys?

Unless you are planning to move soon, I would try and solve this problem with blinds/voiles before reporting to the council.

Do you want to start a war with your neighbours?

Erm it's entirely accurate under the General Permitted Development Order in England. As I said there may be other factors under other legislation but that wasn't what was being discussed.
Over 30 years in planning dealing with this stuff.

That’s not quite accurate
If an extension forms a boundary and sits on the boundary line into the neighbours you cannot put windows at ground level.
If it sits back from the boundary line then of course the neighbour could just put up a 2m high fence. However, if the window overlooks a habitable room or personal external space ( that’s 5m from your back wall) then, no, you can’t do it.

Even if the garden room is an extension, if built under permitted development there are only restrictions on first floor windows in side elevations. At ground floor level they can go anywhere, be fully opening and clear glazed. If PP is required, then restrictions can be imposed.

Again there may be restrictions under Building Regs, but that is not what is being discussed.

OP has called it a garden room.
She mentioned she lives in a terrace and it looks into her daughters bedroom.
I understood it was a classic Victorian terrace with a large extension attached to the house.

Hence whilst you can get permitted development based on volume and length, that doesn’t mean you can stick windows wherever you like, nor does it mean you can, for example…drain into your neighbours, build onto a party wall, block out lots of light.
Theres planning, bregs, party wall awards, rights of light etc etc Lots of stuff to deal with. No one can think I have permitted development and just do what they want .

The same with outbuildings……..

If I have understood correctly, the OP is referring to an outbuilding, not an extension. The rules for permitted development are different for each.

There are no rules relating to windows in outbuildings built under permitted development in planning terms. You can put them where you like. There may be controls under the Building Regs.

Dunelm day and night blinds look good As do the blinds you pull up from the bottom so you only need to cover the bottom half.
or as others have said the window clings / film.

That's good. I wish they'd come out more with us...we discovered a problem with the drainage 10 yrs after the build was completed. I'm now faced with ripping up my floor.

But in terraced housing, especially those with small back yards like the OP describes, there are often windows overlooking the neighbours yards.