How to Become a Cave Man

Anthony Repetto
Published in
16 min readFeb 27, 2024

~ details for cave-city construction on a budget ~

Photo by Vruyr Martirosyan on Unsplash

I like amenities in my house! Hot water, hot food cooked for the whole crew, comfortable and private accommodations, no bugs, fancy tile flooring and decorated plaster walls, fast satellite-uplink internet and solid sound systems, game room, with at least a dozen high-end rigs on a LAN for team games, of course, and a sauna, a Billiards-Hall with liquor bar, craft-hobby and art studio spaces, fully equipped, and a multi-floor home-theater projector-system with cozy-cushion & hammock-nook seating for 50 people… starlight-LED geodome Globe Theater atop the stone roof for performers and events, dance floor — oh, and don’t forget the 200ft by 30ft Pump-HEATED Hot-Tub LAGOON at the bottom of the hill, with sand beach just-as-toasty-warm, to dig-your-toes-in while you watch the stars in the wilderness… wait. That’s a CAVE-city?! And it’s cheaper than RENT!

How the Living Fnck?

It’s actually really easy to manufacture caves. You save money on the building, so you can spend a LOT more cash on what goes-on inside! And, if everyone at a site pitches-in toward an ‘Amenities Fund’, then a Tribe can afford a whole lot of nice things to share and enjoy together! Pertinent details ensue, described in each section: The Physics of Cave-Craft; Where and How, and Logistics; Budget & Timeline; Operations & Daily Life; The Key Protocols for a Self-Reinforcing System; Seeing It from Within

The Physics of Cave-Craft

Rocks are actually EASY to crack! You just WET sandstone, which is between 10% — 30% porous. Once the water has soaked-in deep, you lay a grill of hot coals against the face of the rock. That heat radiates and reflects, pushing deeper and deeper into the sandstone face. That heat BOILS the water within the sandstone, and it CANNOT escape FAST enough! That STEAM-pressure inside the rock-face causes rock to BURST-off in a slab!

[[ You WILL see the nearest-to-the-surface moisture steam-away as you burn… but it’s that DEEP water that SOAKED inside which cannot escape quickly. You want to raise the temperature of the rock-face as QUICKLY as possible, for two important reasons: less total fuel per pound of rock burst, AND a steeper ‘heat gradient’ — it gets hot quickly, without time to diffuse or re-radiate away or steam-off, for efficient, larger single slabs instead of many small flakes. ]]

Once you have completed a small burn, you spray the area down again. That SPRAY is with a *small* amount of high-pressure water — just use a WaterJet pump-sprayer if you want! As that water hits the hot-rock surface, it triggers rapid COOLING, which induces MORE fractures and embrittlement! You *double-dip* your fuel-to-dig ratio, by getting it to cool FAST. Pick one spot on the wall, high-up, and spray continually at that ONE spot until it cools and finishes cracking. Then, move to the next spot over. That way, each piece of rock is cooling SUDDENLY and FULLY, to maximize total fractures. You are, simultaneously, re-wetting the rock for the next round of burn & steam! So Easy!

In general, you will want to construct Baffles, which are just sheet metal panels on hinges and frames, to SIPHON the flames in a deep tunnel ALONG the sections of wall or floor that you are burning. (NEVER dig UP!) By erecting a very tall Chimney outside the entrance of your tunnels, you can lay Baffles all-the-way-down your tunnel, along the floor, and up into that Chimney. So: the flames are pulled along the floor, under the Baffles, so that they touch the stone close, flowing all the way out of the tunnel, up the Chimney, without filling the tunnel with horrible smoke and flame and soot!

As you burn repeatedly in the same location, you will want to wet selectively, and you can also lay slightly-moist clay in rolls and discs to cover areas of rock which you do NOT want to crack! The clay is ‘sacrificial’ — as the heat of the burn boils it, the clay shields the rock beneath. With a worm of moist clay laying like a Track Race starting-line, every two feet as you wind down a tunnel, then the burn will leave those clay-stripes as high-spots, while the regions in-between them will crack. After a few rounds of these clay-worms, laid on the same locations again, then the ‘carved’ sections of the floor will scoop-out their own Stair-Steps! Similarly, cubbies and shelves, window-portals, smoothed-over railings and tables, are all easily shaped by protective clay and selective wetting!

Where and How, and Logistics

You want to buy land that is Un-Buildable for normal, modern homes. That way, you are not competing with them, and so the land is CHEAP. Sandstone bluffs, with acreage of high plateau, are the ideal. We have those scattered across the whole Continent!

Then, you need a solid crew, on shifts, to keep the heat in the rock, and maintain the cycle-timing for efficient construction. If you only “camp-out and do a few hours of work, on some weekends” then nothing will happen. The Crew needs sturdy equipment — Diesel generators, Pyrolysis Barrels, Steel-Frame Baffles (aluminum melts too easily, deforms under load when hot, ceases to act as a siphon once air-flow can seep-in), and Water Jet washers, hauling buckets with heavy wheels and bottom (vs. top-loading) that you can rig to a continual pulley system. You are NOT hitting rocks with a stone axe!

You’ll want to use rock-coal for fuel, as much as you can, because it’s cheap. Straw bales and woodland debris can be pelletized and pyrolyzed to make good char, too. Do NOT BUY charcoal, NOR turn actual wood into charcoal — both are too expensive, and that is because they are horrifically wasteful! When you use rock-coal or pyrolyzed straw, you are producing less CO2 exhaust than a modern home’s construction and maintenance — it’s actually better for the environment. (…especially because the structure lasts so long, with such a LOW HEATING & COOLING requirement — the whole CITY is a geo-thermal battery!)

Rock-faces must be MAPPED carefully, first. And burn-crews are laid at ALL faces at once, extracting simultaneously. That is important, because ONCE you lay your grill against a rock, there’s nothing left to do for a half hour. You better leave that burn-tunnel, now, too… so, go next-door to the other cave-entrance you’re working-on, and spray it down, because it’s right on schedule to be cooled-down enough to walk-around in your insulated fire-pants!

So: the whole site is developed on shifts, by a crew, to lay-down the Main paths of Air-Flow. Once those Main Routes and rooftop vents have been carved, then additional burns can slow-down and speckle-around within that lattice-grid of tunnels, to fill-out more cave-camps deep within the hill, as you please!

By digging many layers deep, across just a couple acres, then a single cave-site can hold as many square feet of useable interior spaces as a DOZEN city-blocks!

Budget & Timeline

You pay for the equipment ONCE. You pay for fuel at a fuel-into-rock rate. You provide your own labor, and the initial training-time. You get a huge tunnel-labyrinth for yourself and a few hundred friends. What is the cost per square foot, time in labor per square foot, and how quickly would that let your Tribe GROW?

Dudes can shovel about 2 tons of debris per hour. And that shoveled slab is taken on a tiny trolley out of the tunnel, to be dumped into a rock-crusher, which sifts and feeds the sandstone → sand! You fill sandbags, and lay them like bricks, with cement-pour in-between as mortar, rebar shoved between them. The excavated sand is NOT hauled-off to a dump-site — it becomes the Low & Wide Retaining Wall along the edge of your property, set-further-away from the face of the cliff, at the bottom of the hill. There, once the retaining wall cups a vast, meandering trench between itself and the face of your bluff, then you dump the NEXT batch of sandstone → sand INTO the trench-region between them. That sand will become your sandy beach, with pipes beneath the sand, and layers of charcoal from pyrolyzed straw as a water-filtration system.

The heat from engines inside the cave MUST be exhausted; engines won’t function if they over-heat. So, cool water is continually circulating into the cave-tunnel depths, to the engine-room! There, the water heats, and it is pumped-away to the Heated Lagoon. Under the Lagoon, deep beneath the sands, the water pushes heat into the sand and filters itself as it rises to the surface. You’ll want to add plenty of day-spa minerals, especially because that will discourage people from drinking the water, and it will prevent microbial cultures from growing!

Fuel and power systems are all able to integrate in this way; the natural geothermal battery levels-out temperature, and the wind-front that strikes the face of the bluffs will push ventilation along whichever hallways and portals are left ajar! So long as chimneys and roof-vents are aligned at intervals, along the top of the cliff, then nature does most of your work for free! Lower energy costs, less total equipment per person, less CO2 footprint, lower maintenance costs. Those add-up!

So, many of the costs of suburban life CEASE, and others are integrated into systems for FREE. You can spend as much as you want on decorations and cool toys, because the fuel you burn when you MAKE the cave is less than $2 per square foot, and you can dig-out 2 square feet of cave per hour (which is NOT just ‘dig-only’ labor; that figure includes the estimate other labors of operations), such that you can make 100 square feet for yourself with $200 and 50 hours of work!

If the *initial* crews of cave-burners are focused on building-out the cave’s utilities, while living in hovels for a little while, then Crew A of 100 people could build enough caves for *another* Crew B to join the site… in only a few weeks of work! By year-end, due to such a rapid ‘doubling-time’, then a site that began with accommodations for 100 folks could balloon to multiple THOUSANDS of campers!

Operations & Daily Life

Caves must manage a schedule; you shouldn’t have to. So, delegating various tasks and responsibilities among folks who focus on that? — yeah, gotta have it. You, personally, might get wrangled-into helping some tasks, if a shift is falling behind and needs some of the grunt work done quick. Otherwise, you do you! And, a coach is helping to coordinate your efforts with a Scheduler who is managing everything.

The Kitchen & Cafeteria MUST be a large, contiguous region that is either at the Top or Bottom of your Sandstone Bluffs, with a dedicated team of actual, responsible Chefs, good equipment, spray-wash sinks, with the hot-fires located OUTSIDE. Do NOT give me a reason to suspect Carbon Monoxide poisoning, at all. You won’t like me.

Similarly, Latrines are a separate nook, connected by a long hall to the rest of the rooms on each level of the cave system. Latrines need a separate vent-tunnel, which ONLY rejoins the Rooftop Chimneys at the end. All Latrines scoop the same draft for themselves, while NONE of their draft moves through other rooms. Otherwise, it would really stink.

Bathing must be managed properly, too — you cannot have ANY risk of large *volumes* of water-intrusion in the sandstone beneath you, or you risk the longevity of the structure. So, the Lagoon is the heated bath outside, and you can have showers there, too. Each shower in its own cubby, sure — but those showers have to be near the OUTSIDE edge of the bluff, NOT deep within the structure!

Game rooms, theater, sauna time… all those amenities need to be scheduled fairly, too. I strongly suggest that scheduling happen via Vickrey Auction using ‘points’, which is fast and simple. Members can earn ‘points’ automatically, just by being a Member in good standing, so that someone who is away for many months can return and enjoy amenities immediately. They should also receive ‘points’ for the days staying-at-the-caves with good behavior; those are the ‘share’ of amenities that everyone is paying-for with their Amenity Fund. They should also receive ‘points’ for helping to maintain and monitor the space which they hope to utilize — so that devoted Billiard-Rats can score extra hours on the tables, by keeping their love clean and safe! Similar auction-models help distribute the Amenities Fund spending plans among craft/game/event spaces which each appeal to various ‘clumps’ of Members, such that every Member has at least some of their interests met on-site. [[ i.e. — “I have a dozen different interests, and so do each of you. So pick your top favorites, and see if there are any clumps-of-interest which are large enough to justify a Game/Craft/Event investment from the Amenities Fund; no one should be left-out, and no one should get lots more amenities than others.” ]]

The Key Protocols for a Self-Reinforcing System

There are certain ‘structures’ in a Cave-Tribe’s WAY of making rules, which are necessary to keep it healthy and growing. (math guy saying this, from game-theory and systems-dynamics perspective!)

FIRST: you CANNOT have individuals ‘own’ each cave, nor can they ‘rent’ a cave. Both are huge *catastrophic* failure-modes, and engineers want things to “fail in ways that are NOT catastrophic, even if that isn’t a higher average performance.” That’s because we care about those people who suffer from the catastrophic failures, and we have the foresight to understand that gamblers always leave the table with zero. Cave-systems, because of the Big Concerns (earth-damage, water-damage, air-ventilation, fire-hazard, crazy-stupid-evil-goblins) definitely cannot be repeatedly sold, renovated sloppily, or leased. Ask any landlord!

Instead, the people who stay in caves MUST be Members of a Group, all of them. (Guests are welcome to stay… if they contribute!) They have an Operations Budget that they pay with a Fee for their Members’ needs (while staying there), and a Contractual Obligation to contribute to the Amenities Fund (while staying there). And, to bind that Cave-Tribe structure in the modern day, the ‘owner’ of the Property would need to be a Land Trust composed of those Members.

Now — don’t get stuck in the ‘box’ of thinking ‘one-site = one land-trust tribe’. Nope! The REAL stability and success comes from POOLING members and sites; like the KOA for RV vacationers, we want ALL sites in the country to be linked. And MOST importantly, they are sharing a Member Allotment Agreement:

“If I am allotted a certain number of ‘square feet of cave camp-grounds’ for myself and guests, then I can *schedule* to use THAT many square feet at WHICHEVER site I schedule-for. That way, my team or tribe can MIGRATE among many sites, consistently receiving the same amount of room, and similar quantity and quality of amenities. NO one is buying and selling real estate — that would only give Real Estate Agents 6% of the value, and more as TAXES. Membership Allotment is the Credit I have Earned through Work for the Community, and it travels with me to ANY site in our network.”

The next Protocol ensures that residents always help to *expand* access to more new-residents, and that more space is always becoming available for new interests and activities: the Jackrabbit Protocol. Each member who seeks an Allotment must also help to construct (or facilitate in other areas worth equal labor) SIX TIMES that area of cave that they keep for themselves. Ouch! That sounds harsh — but look at the actual needs of the Cave City:

If I want 100 square feet of studio-cave-camp for myself and a friend, then there are ALSO hallways and air-duct-tunnels, as well as the Latrines, the Cafeteria, the Game Room, the Sauna… oh, right. The Caves are NOT your room alone. We can roughly allocate 2x your square footage as halls and other rooms; that’s 300 square feet of cave, for your use. NOW, we MUST double that amount to 600 square feet of total construction— THAT is the Jackrabbit Protocol. Each ONE person makes room for TWO, like a Hydra-Head. So, we keep growing. ;)

Next, the Reason for someone to BEGIN putting-time-into a Cave City’s construction, so that other less-burly folks can ALSO enjoy the life: Incentives from the DIVIDEND Protocol!

When a Member or Guest is staying at a cave-site allotment, they are paying an Operations Fee (food, fuel, satellite internet, mech-ops & maintenance, toiletries & cleaning products, etc…) as well as an Amenity Fund (with bid-votes toward numerous *clusters* of Amenities, such that each Domain has Coverage for each Cluster of interests…). That Amenity Fund *includes* the DIVIDEND paid to those who constructed MORE cave than the Allotment that they use. Huh?

Suppose you show-up in the early days of your cave-site, and you and the crew are digging just enough to sleeping-bag-in-a-pit, to get started. It’s rough. And uncertain. And you’re putting time, money down, upfront. That requires an Incentive, to remunerate the work. So: Anyone who digs MORE than their Jackrabbit Allotment is going to receive a Dividend from the cave-space they made, for the whole future of the cave-site’s use. If you dig 2sqft per hour, and you are digging a LOT — 3,000 hours per year… then you’ve made 6,000 square feet of cave in ONE year. That’ll get you the entire dividend-share of the Amenity Fund from TWENTY different cave-rooms each 100sqft in area, for the rest of your life. Considering the low cost of living in your cave-city, you could retire early!

Hours & Dollars Protocol

The cave-cities will always need hours of labor to run things, as well as dollars to buy things they cannot produce. And, the caves will WANT to generate sources of income, however they can in their region. To keep everything roughly balanced, there MUST be an allotment of Hours and Dollars that each Member or Guest contributes whenever they stay at a cave-site… AND if that person does not want to provide hours, then they CAN substitute for dollars at a poor-trade-rate; similarly, someone without dollars can substitute by providing more hours yet at a low dollar-rate. We CANNOT allow a one-to-one conversion; there must be a ‘handicap’ to the trades between Dollars & Hours or else leverage and imbalance cause systemic weakness. Keep an even-keel! [[For example, if the Membership sees that its Operations Costs are, on average, 2.4 hours of labor per person per day and $7.60 consumables per day, (which is doubled to provide for the Amenity fund, to $15.20 per day cost-of-living) then you could agree to “Avoid an hour of labor if you pay $25 dollars, instead” — which would encourage people to pay-instead-of-work ONLY WHEN their alternative salary is more than $50K/yr. And, “Avoid $10 of payments, if you work an HOUR instead” encourages ONLY those folks with low-incomes to pitch-in extra labor. So, I could live in your cave-community by paying-cash-only if I pay $75.20 per day, and I’ll be completely pampered, not even needing to do any cooking or chores, which is a CHEAP Vacation! Or, I could live at $0 cost, no food or utilities bills to pay, if I’m willing to put-in 4 hours of work every day, on average — that’s only 1,360 hours per year, which gives me plenty of time to pursue my art, craft, upskilling, family, etc. ]]

Vouching & Violations Protocol

Specifically *because* the Members can move between sites easily, AND bring guests, THAT is why there MUST be strong enforcement of good behavior, with readiness to expel Members who bring abusive or destructive guests, or who steal or harm others or the cave-sites. The Membership is NOT a Public BAR for dumb-bros; Membership is RIGHTLY selective of productive and collaborative people, or else it dies. Tribes around the world have always held a Standard of competency and commitments; Cave-Tribes will need that to last.

Seeing It from Within

You woke without an alarm, again — just the whisper of the winds ruffling the tapestries in the hallway, outside your den. They carry smells of waffles, eggs, bacon, coffee, fresh juice, wood-smoke tingling the back of your nose. You take the bench-seat micro-gondola down the Wide Stairs, yawning and laying across the bench wrapped in your Furs. A bell tinkles as you reach the bottom of the Gondola-Loop, and you roll-off the bench onto the padded floor, shuffling in slippers to the Cafeteria, where dozens are already chatting and laughing, smiling to you as you step into the bright morning under the Uber-Awning in the breeze.

You have a few shifts, today — a morning garden-ops that you agreed to fill-in for Ken. And a class in the woodshop you have to Assist, because you’re more afraid of table-saws than all of the other students, so the teachers trust you. And chores — you loaded-up on them, for today, because you want to have the entire weekend unencumbered, to take one of the Site’s Tour Buses that is scheduled to head to the Bay Area for all of Saturday, hauling everyone home drunk and happy after a spree on the town.

And, if the weather is good, in the evening, there’s always pick-up work to grab in the Rubble Pile, for processing the excavations. The more hours you put-into the Shoveler’s Guild, the more Dividend you’ll earn, every year! Or, later, you can use all that extra excavation of yours to upgrade your camp-cave to a larger Den, or multi-den network of its own. If you and so-and-so decide to settle-down, then you can combine both of your square-footage-Allotments, for a whole house-worth to yourselves! You might just decide to lounge at the Lagoon with a drink, or play a few racks of pool… with a drink! It’s wonderful, how every resident writes their name on a pair of barrels, and then the team of Brewmasters manages them all, in the Cellar! Cheap, unique craft beers… made to order, local… made with HEART! Even if you’re shoveling rubble, that sounds like a gorgeous evening.

Between your shifts, you stop back in the Cafeteria for snacks, chatting with whoever is milling-about at that moment, wandering away to look at what others have been working on. Game tables, game rooms, resident artists’ newest pieces snug into a corner of a shelf, cozy reading nooks… you mingle your way to the Atrium and Herb Garden, to sniff at their extract-distilleries! Among the flowers, your Apiary’s colonies gently cull pollen for your tea. Angora rabbits in their own, private cave, lure you into a cloud of the softest marshmallow-fur for a while, their Breeder standing in quiet discussion with a few Textile Majors who moved-in recently to spin the luxurious bunny-fibers!

After that strong beer and an hour and a half of shoveling, that evening, you showered while watching the sunset, and sunk into the Lagoon to relax. Tomorrow afternoon is when the Bus arrives with the Friday Concert Ticket-Holders, to see the bands who we had invited to stay here with us, while they tour. Tonight is the quiet simplicity; tomorrow afternoon when the Visitors arrive, you’ll be managing the Booth of your friends’ Art Display — one of them has their new watercolors framed, and the other finished firing another grotesque sculpture! Every week, another few thousand folks get a good gander at your friends’ work, so interest is rising, which means prices do, too: you grin when they insist that you help put NEW stickers on their pieces. “$175? No. That’s… say $240. Worth it.”