It really would be better to move the bathroom upstairs. Can you do a 2 storey extension?

Why not leave the bathroom where it is?

Or move the bathroom to the middle of the rear extension (behind where it is currently) and have the longer lounge extended on the left and the longer kitchen diner on the right. I think the extension is too narrow to have a room across the back anyway. Also gives you storage in the hall for coats etc.

We dont currently have the finances for a double storey extension unfortunatlely :(

the extension would be 4m so rooms dont think it would be two narrow? i get what you are saying about extending the room and i have throught about it but i dont think that elongating the two rooms either side wouldnt work for us because we would end up with a really big hallway and then no connection between the 2 rooms ...so confusing!

yes weve thought about leaving the bathroom but its smaller than we like and no windows - ideally we want a window we can open. its an option though. to make it bigger and extended slightly out would impact on the space in the extension

Options will be based on many things such as budget, flow of how you use the house, load bearing walls (removing these is expensive), light into the house What direction is the front and back of the house facing) and the position of services - mainly drainage and soil stack; this is not a full list but just a few important points.
A possibility which you may not have considered is to put a new insulated and tiled roof on the conservatory. We have done this and the conservatory is now useable all year round and the cost is nothing like that of an extension and is why we did it. However, if you go down this route make sure the installers do a thorough survey and ensure the structure and foundations are suitable and able to take the weight of the roof. Also, if you do go ahead with the extension, make sure the foundations for the new construction are suitable for a 2 storey extension so that you have an option to do this in the future without major work; this shouldn’t add too much to the cost. You don’t say what type of roof you propose for the extension but if you want to retain the option of adding a second storey at some stage I would go for a flat roof.
An idea for reconfiguring from your plan could be to move the bathroom to the back in the centre which would provide a window for the bathroom, remove the walls of the kitchen and lounge into the extensions done add patio doors into each and also remove all the walls that currently form the bathroom (except for the one at the rear of the hall) to make an open plan including lounge and kitchen/diner. I suspect this would be expensive though.
Hope this helps.

Why not build a two storey extension but make its footprint smaller to make it affordable?

Depending on how much space you have to play with at the back of the house? What is the most important room that you need the extra space ? If you are wanting a large kitchen dinner, extend on to this part leaving the bathroom where it is. Remove the conservatory so the bathroom has window/light. The lounge remains in tact with doors added for access to your garden. The large extension to the kitchen would leave you plenty of space to design a layout that works for you.

@paul do you mind me asking how much the roof was and what roof you put in? We hadn’t thought about that option but it’s a possibility. I think we will be removing one load bearing wall so aware we need a steel beam(s) added which bumps price up. I think we will end up keeping bathroom where it is tbh now after consideration and trying to get a better fan system for ventilation.

I don’t think our area allows many double storey extensions in our area, plus we are terraced so would have to go 45 rule and do it will just be bathroom. We may do it as it’s a good idea.

I think we are used to the space of the whole conservatory so if we only extend on one part, we are effectively ‘losing’ all that space and paying for the privilege!!

Thanks for all the comments guys, lots of food for thought

Hi Achaean, we SEF a company called feel Warm (based in Stone in Shropshire) to install a Supa Lite system. The whole job cost £7K which included all the plastering inside, electrics - 4 LED spotlights (dimmable) and 4 external down lights; an excellent job and I can thoroughly recommend the system. Our conservatory is an ‘extension’ at the back of the house off our dining room. We had it done about 2 years ago and as I say we had exactly the same problems of too hot or too cold it this is now an extra room we can use all year round. If you look at the web site you will be amazed with the thermal efficiency achieved. Hope you manage to get something sorted out. Take care.

Sorry Charan my reply above is full of errors due to predictive text!! It should have had your name and we used not we SEF!

Thanks mate I worked it out! I will take a look, thanks for the help 👍🏼

If you are either extending or simply proofing and re-glazing they conservatory, you could put a partition wall across the living room and put the bathroom at the front of the house.
Then open up the rear lounge wall, using an RSJ, which will give you back the lost space and would flow across the rear aspect and connect to the kitchen. As it currently does.
The old bathroom could be used as a separate WC, Utility room or storage. The only thing you would lose would be direct access from the hall to the lounge to the. Sorry my diagram has just been done roughly by free hand...
The only

Don’t fall into the trap of thinking size is everything. It has to be usable, functional space. What do you use the conservatory for? Do you often use the lounge? Would a utility room be useful? Do you tend to eat in the kitchen? Do you have lots of people round all the time? Go back to the drawing board if you have to. Think about how you are going to use the space. You seem to be putting a lot of focus on a bathroom which is dictating everything about your design. Think it through or it could be a costly mistake.