Well, it’s interesting as I live in a similar bungalow and I’ve just upgraded mine throughout the year.
First of all mine was in good decorative order with a newish central heating system and newish windows and doors.
Another thing it will depend on is labour in your area. I know a lot of good people who charge me a fair price and I still managed to spend £15,000
I had a full rewire. That’s a bungalow ,that’s about 1000 sq feet
A full repaint,
Laminate flooring in large lounge, hall, bathroom, kitchen, and master bedroom
New garage door, new path measuring 3 feet by 30 feet
New outdoor lights. And some indoor ones
New fence measuring about forty feet long and five feet high
New decking measuring 12 by 25 feet
New kitchen cupboard doors
New guttering all around the house and fascia board
Outside of house repainted
Front of house rendered and side of garage that is overlooked by house
In back garden I have a white wall which was repainted
In the front I have an ornamental wall about 2and a 1/2 feet which I had painted
I also paid for two skips...£250 for the two
Front patio cleaned and jet washed
It’s beautiful. Like a new house but as you can see I didn’t have to pay the £3,000 for new central heating or £4;000 for windows.
The decking was probably my single biggest expense at £2;000
Followed by the rewire at £1800.
Hope that helps