You can do this already, how much would each individual in a large polycule end up paying towards the monthly bills? Adding more people to the house makes almost no difference to my monthly expenses as its almost entirely mortgage and council tax which won't change with more people. Monthly costs are like house/tax £1300, food £60 each. Maybe a little more energy from more showers, but reduced heating in winter as people put out about 100w of heat each.

Get some pod bunkbeds and really fill the house with people. 2 bedrooms? Lets stick 12 people in there, decent pods will cost several thousand if you want something extremely good and sound proofed, basically fuck all compared to the cost of a house. Larger bedroom can have pods stacked 2 high and 1 stack in the smaller bedroom with 2 in the larger one, each taking 2 people.

Overcrowd your way to affordable housing but with a little bit of money (which you more than make up for in the housing savings) and you can have it pretty nice.

Current costs about £750/each for 2 people. Make it 12 and it comes to like £150-200 each. Just think how little work you would need to do! Or how much money you could have for luxuries.