Build Attic Room Need Help!

[jaslim13 0]

Hi looking to build an attic room with a staircase leading up to it in my 2storey terrace house.

Things I want to do:

1. Open third storey aka attic room!

2. Staircase leading up to attic preferably this kind:

3. Flooring of attic

4. Build a toilet in the attic if possible

5. Windows in roof to allow more light

To do all these, will 30-40k be enough?

I understand I have to buy the floor plan and all, but not sure what is the difference between a PE and a architect? Anybody did attic before? Can recommend or PM contacts? Thanks loads really really need help :(

Btw if my sister is an architect, can she draw and approve all the plans? How much will I save like that?