Hi there, I think that the skylight would definitely be the way to go, if your budget runs to it. It will really lift the whole stairwell and make it much lighter and brighter. Full height frosted doors may be OK on the laundry, but I wouldn't recommend it for the bathroom as when lights are on in the room, you may be able to see more than you bargained for, from the corridor. The occupants of the house may feel comfortable with it, but any guests or visitors may not. A frosted panel at the top of the door would be as far as I'd go. Bear in mind too, that glass lets more sound through than timber, and in a situation like yours, I'd recommend a solid core door, for that reason. I hope this helps!

The Less Glass in your shower area the better - if you can avoid it. Eventually shower screens, no matter how effectively and often you clean them will deteriorate over time and shower signs of glass cancer. If the space allows it, effective planning can allow shower walls and other alternatives work effectively without the worry and hassle of cleaning glass. Thanks Paul

Thank you everyone! Between you all you have summed up my concerns (changing bulbs, enough detail already in the stairwell, honouring the old house) and my desires (a nice lantern pendant or period light, LEDs need less changing, overhead lighting. I like the idea of the wall lights but we have not wired for this. There is wiring for for stair lighting (phew, glad we got that right) and one down light in the middle of the void. We have reconsidered a pendant as the one down light will be harder to change but are worried about obscuring the windows. Perhaps one of the simple fine-framed lantern pendants or white vintage light, on chains will be easier to change as we can pull it across to the stair, or a pulley pendant like this I'll post some more photos of our reno once its further on.

Different manufacturers have different track and sill details. You need to contact the manufacturer of your doors and get a drawing of the section of the sill and track, as well as ask their advice. I would be carefully considering how much water will reach the door frame when it pours with rain (how much protection does the eave offer). It also depends on the existing structure (if you are renovating) and exactly what you are cutting away to lower the door frame. You will run into issues if you have to cut out the edge of an existing slab. I suspect that it is not as simple as you hope otherwise it would be done all the time. So much potential for things to go expensively wrong if you don't plan it carefully to the millimetre. You can see in this photo it is not your standard track, and that a grate to drain water runs parallel to the door to minimise the risk of rain water being blown in. I wouldn't part with any cash until you have worked out all of the little details. It is a general rule of architecture that if something looks flush, clean and seamless then somebody has put a lot of thought into how to achieve that result, and the tradesmen involved have been much more careful, precise and taken their time to get it perfect. All of this costs money.... Best of luck, Dr Retro of Dr Retro House Calls