I have a garden that I don't use. It's about the same size as the footprint of my flat. I think it would be a much better use of the space to put another house on it. I'm unlikely to ever actually do that because planning application to do it would cost money and be a lot of hassle. I don't know the odds of actually getting the planning permission but "low" is likely a good first approximation.

There are 27.6 million households in the UK and 80% of people have access to a garden so I think there is decent scope for there being more than just me with a garden that would be better off as another house.

If someone were to offer to do the planning application (and build) for me in exchange for a split of the sale of the new house, I'd be keen to take them up on that. (If anyone does want to make that offer please get in touch.)

I think there is a workable business model in making that offer. The odds of getting planning permission for any one application might be "low" but make enough of them and some will come through. If you're making a bunch of planning applications you'll have some economies of scale. You could go nuts and automate the whole process (plonk plans for a kit home on map for the site; submit that) and just spam them at planning offices, but I think that's likely to just piss off planning officers and get them all rejected. Something with automated preparation and having a person check them over and only submit ones with best chance of getting approved is likely to work better. Should be able to learn (either with machines or people) what features influence the probability of getting approval.

There's tens of thousands of pounds of value in each successful application so even with a "low" success rate that funds a bit of work on all the applications. Could experiment to find the point that gives best ROI to working on the applications. As you scale up there's more scope for more sophisticated automation of the preparation and ranking.

Once you've got planning permission it would be pretty easy to get loans to cover the cost of actually building. You could just sell the plots once they have planning permission and pocket (your split of) the value of the planning permission but I think it would work better to do the building yourself: there would be economies of scale there too.

This could be bootstrapped by a person/team with some knowledge of tech¹ and planning applications. I don't have the knowledge of the planning process side of it so I'm not likely to do anything with this idea. But I think it has legs, and building more houses is definitely important. If anyone does have that knowledge (or the money to hire it) I'd be keen to talk. Or if anyone wants to run with this themselves: I'd be keen to be a customer.

1. I'm not actually sure there is much/any new tech required here. Manually filling in details on a template planning application would probably work, depends how long that takes and the success rate of the applications.↩