Ballpark figure for conversion of rumpus room to self contained unit

[KeriA]

Hi there, this is my first post and I'm hoping someone can advise me - I have an approximately 40sq metre rumpus room attached to the back of my garage. I want to turn this into a self contained unit and rent it out. I am in a position where I desperately need extra income to pay my mortgage. The council says it should be possible if I have agreement from my neighbours. I have limited funds and absolutely no knowledge about how much it would cost me to do this. Currently it's an unlined block building with a toilet and a kitchenette. I would need to line it, add a ceiling, add a shower and possibly a laundry? Plus heating and possibly flooring as it's a concrete floor with threadbare carpet on top.I don't want to pay for a draughtsman and all those council costs if it's going to be way out of my price range. I need a rough idea of how much this would cost all up, before I do anything else.Any advice at all would be very much appreciated! Thank you.

[Eugene]

Talk to a plumber and see if they can add a shower with just a small building consent - some plumbers particularly bathroom specialists will help with consents.
I have been paying around 3k for a shower refit or new shower - probably too high but with existing tenants it is important to me to get a quality job done quickly without fuss.
You need a permit to add insulation to existing walls. Though it is tempting to overlook this, if the council have already seen the dwelling you will definitely need a permit.
For cost of insulating and lining, ask round for sharp prices, ask friends for a good builder.
The heating could wait if the room is insulated.
You could look for a second hand carpet.
Once you have rent coming in you could look to add a heat pump, put new floor coverings in and put new kitchen fittings in.
With the toilet and kitchenette already there, you are off to a great start and I would recommend you do your best to do the conversion.

[Leftette]

"The heating could wait if the room is insulated." What rubbish. All the insulation will so is keep the cold air in. You still need to heat the air.

[Eugene]

"The heating could wait if the room is insulated." What rubbish. All the insulation will so is keep the cold air in. You still need to heat the air.

Yes, with a portable oil heater to start with.
Then a heat pump once cash allows