In the U.S. you can sell a home "as is" and disclose the tunnels as a safety risk. The buyer can fill in the tunnels if they don't have a need for them. Homes are sold all the time with defects, code violations, etc... Sometimes the land/location alone is the primary value of the property. That is the case in my neck of the woods. Several of my neighbors had dilapidated homes with rotted wood, 100+ year old redwood septic systems and still sold for seven figures. I have no idea if you can sell a property "as is" in the U.K. I also have no idea in what neighborhood Colin resides.

The man probably makes hundreds of thousands and up to low millions of dollars per year from YouTube money. Not to mention sponsorships and Patreon and any other sources of income. Pretty sure his house could go to zero and he'd be fine, financially.

He's stated previously regarding just the bunker, that it'd be sold as a bunker with a house, not a house with a bunker. That arrangement is apparently more valuable as that makes the house much more desirable for the type of person interested in bunker-digging.

I'm not sure if the tunnels change anything, but assuming they're up to some sort of code, probably nothing.

> I suspect that it will be impossible to sell.

Genuinely curious to why that would be? Subsidence?

Any unusual or one-off traits that seem "unique", "fun", "quirky" etc tend to do very badly in the actual real estate market. Often, they are poorly engineered and will be a maintenance nightmare in 20 years. Inspection expertise to be able to tell whether it will be a maintenance nightmare will be very tough to find. Most sane buyers will just pass on it rather then try to sort it out.

Even if the market is super hot right now and it seems like people will buy anything, anyone who looks at buying this will definitely be thinking about how hard it will be to sell in 10 years when the market isn't so hot. Most likely 90% of them will either back out or demand discounts that basically assume the whole thing is a mess and will need to be ripped out by professional contractors.

In addition to what ufmace said, the vast majority of buyers in the UK do what has just been changed to a RICS Home Survey. These are reports written by chartered surveyors, meaning that these are not just best effort opinions, they have legal implications. Some mortgage providers will not agree to lend without having a fresh one to consider.

They list all kinds of small details: a single double glazed window containing condensation, or a gutter leaking onto an exterior wall. Experienced buyers would know which of the details are actually important, but it's still a sobering document. They encourage buyers and mortgage providers to act cautiously and are typically used as a tool for negotiating the price down.

If you are a cash buyer and just don't care, then fair enough. But whether or not it's a sound piece of engineering, a DIY tunnel (without planning permission?) dug underneath the property would be a massive red flag for your solicitor and your surveyor who would likely provide professional advice against buying the property. And mainstream mortgage advisors and insurers and may even refuse to do business with you due to perceived risk.

If the bunker is permitted then he's going to have no trouble selling it - though the market does tend to get weird when stuff looks weird.

That said, I have trouble believing in the current insanity of urban property markets that anything could make a regular house hard to sell. It won't make it more valuable (nobody's shopping saying "I really need that underground bunker") but I seriously doubt he'd have any trouble beyond that.

He declared over £1million last year, and I'm 99.999% sure that house is just used as a studio/business address rather than actually living there now.

He's done way too many projects that involve just generally making your life a bit difficult.

I'd buy it if he has the right permits and building approvals. House with a tunnel and underground bunker - count me in.

Honestly, super practical for anyone who plays in a band and wants to host practice and have their neighbors like them anyway.

Or has a kid who's in the same situation...

All the other ideas get dark very quickly. In addition, CO2 accumulation makes the mind a bit stupid quite quickly, even in an office, so I wouldn’t stay there…

Or just more living / working space.

Say you're in one of many low to medium density areas (sf, suburbs of nyc, etc) and need more living space. Going up is very expensive and causes conflicts with the neighbors (earthquake zone, views); down is even more expensive; building in the yard loses, well, the yard. So going under the yard is not a crazy option.

Particularly in our brave new wfh world where employees now have to pay for their own working space.