Introduction: Ultimate Dad Cave, Garden Office and Workshop

Ladies and Gents,

I present you the Ultimate Dad Cave / Garden Office according to my best imagination.

Once the mid-life crisis hits, some buy Ferraris. Some climb mountains. I've built a garden office :D

A place to work. To dream. To take a nap. To hide (occasionally).

Please enjoy our family's joint effort of the last 3 months. Feel free to comments and ask questions.


Supplies, materials and associated costs:

Overall cost ~5,500€ (~5,800$) -

  • 942,66 € - wooden cladding panels - both outside and inside
  • 613,58 € - OSB panels for the floor and roof, foam, anti-wind and anti-humidity layers
  • 450,00 € - Stove and internal chimneys, glass under the stove
  • 442,00 € - construction lumber (5x10cms, 2x4inches), plus extra thin strips for the roof
  • 380,00 € - Externally insulated double layer chimney
  • 246,08 € - Roofing, bitumen. rul. coating, ridge parish, OSB
  • 204,00 € - Doors
  • 200,00 € - Wooden floor panels.
  • 200,00 € - Circular saw stand and saw
  • 186,00 € - New computer chair
  • 180,00 € - Gravel for backfilling
  • 158,00 € - IKEA chair
  • 150,00 € - fuel for the 137 trips to the "Home depo" store ;)
  • 112,00 € - Wooden countertops,
  • 50,00 € - Glass package for the windows,
  • 42,67 € - Wood screws, corners, cotton knife
  • 41,24 € - 12cm Torx wood screws, 2x, 200 pcs.
  • 40,00 € - delivery of construction lumber,
  • 40,00 € - extra wood and wood screws, battens,
  • 40,00 € - yet more extra construction lumber,
  • 32,00 € - even yet more construction lumber,
  • 25,00 € - two rubber mats at the door
  • 21,36 € - Meter, expanding foam, foam pistol, etc.,
  • 20,00 € - Two flowers outside
  • 17,51 € - random items
  • 17,43 € - Wood screws
  • 17,00 € - Chandelier in the corner
  • 15,39 € - Angles, gloves, bitumen, nails,
  • 15,39 € - Wood screws,
  • 15,38 € - Two table legs,
  • 14,90 € - Rental, laser level
  • 13,78 € - Extension cord,
  • 12,95 € - 9 cm Torx wood screws, 1x, 100 pcs.
  • 12,95 € - Hammer,
  • 12,00 € - flower holders
  • 11,74 € - Insulation, etc.
  • 10,00 € - Random minor things
  • 9,39 € - Wood screws,
  • 8,00 € - cover film,
  • 8,00 € - Board, planed, top
  • 5,00 € - and wood screws

Step 1: Ultimate Dad Cave / Garden Office - Intro and Highlights

Long time ago, we built a small house on a small plot of land. It had no separate workroom.

My workspace was on the second floor of the house, at the end of the staircase, with lots of traffic. Our kiddos are active, noisy and curious. It was like working in a train station ...

And then Covid came ... that added another layer of mess and all the remote-work madness. I bet you can relate.

Thus, I dreamt of a dedicated workplace aka the Ultimate Dad Cave ;)

A place to work, relax, 3D print & hide (occasionally) ;)

After some encouragement from the Mrs., and having basic carpentry skills, I and the kids built the garden office house.

One wall acts as a Travel Diary for our family.

Time to construct: ~250 work hours; ~2 months on and off, ~4 hours per day on average.

Total cost: ~5,500€ (~5,800$) - as is a golden rule, went over-budget ~30%.

Size: 9.25m2 / 99.566 Square Feet (internal). Roughly 3 meters x 4 meters on the outside.

Insulation: 10 cms (4 inches) rock sheet + heating stove, as it gets up to -30 degrees celsius here (-22 F)

Purely wooden (4 cm walls) garden offices here costs 3-8K€ (no inside stuff included). Thus, I believe I got a good deals out of building it myself.

This project removed most of my other Instructable - namely the hot tub:

EU map was used from my other Instructable as well:

Step 2: Preparation, Foundations and Floors

You can see the hot tub I've built in one of my previous Instructables:

Kids grew up. The hot tub was being used 3-5 times per year, thus it was losing its usefulness. So, up for sale, it went.

It was very, very tricky to get it out. Previously it was dug into the ground ~half height. Upon trying to excavate, I realized there is a significant ground freeze. Had to fill the thing with water and heat it for, like, 2 days straight. That was a weird adventure ...

The hot tub out, I had metal-earth spikes left over, which I decided to re-use for the foundation of the garden office, instead of dumping a bunch of concrete.

Ordered a 6m3 lorry of small pebbles to fill in the post-hot tub hole.

Ordered the construction lumber, treated, ~40 pieces of 5x10s @ 6 meters length (2x4 in, 20 feet long)

Had a long negotiation with Mrs. on which plants to stay, which ones to go and how to protect them during construction.

Metal earth spikes went in first. Hired a laser spirit leveler to do 90-degree angles correctly, also to level the floor properly. This is super important in the beginning. This step is critical, as it saves major headaches later on.

Did cut the wooden columns per each spike according to a spirit level reading.

The initial frame went around, placed on top of the metal spikes & wooden columns. Used double 2x4s, making it 4x4s (10cms x 10cms)

Added extra metal corner brackets just to be sure.

Cut a wooden "spacer" to act as a guide for screwing in internal cross-beams

Added foam panels (0.5m x 1m). Using the "spacer" produced a good tight fit.

Once the foam panels went in, it was time for some expanding foam fun. Nasty stuff, gloves are a must.

Cut and added OSB panels - green is for extra dampness resistance. Did paint the exposed edges with acrylic paint.

Nice, almost level, foundation and sub-flooring in the end ;)

Step 3: Wall Structure

Walls came next.

I bought extra construction lumber, as it was not the major part of the budget (~5%). Thus, decided to build the thing with extra-strength.

Again, the spirit level measure is your friend. Measure three times, and avoid headaches later on. Fixed the vertical sticks with diagonal supporting sticks. It helps to plan doors/windows in advance and do extra support for those.

Decided to do one wall diagonal, so I don't have one corner protruding sharply into the garden.

Added additional diagonal supports for the corners. This proved to be challenging when adding insulation later on.

Formed window "boxes" and added windows. The small one came from my other Instructable (camping trailer). A larger one was donated (used) by a neighbour. Managed to break the glass while moving :/

Added the main roof beam. (10x15cmsx420cms). Raised it a bit to make the roof slopes, as the roof shingles had a requirement of minimal decline of 13 degrees. Used an online angle calculator to find out the necessary beam height.

The build was ready for a roof. And I was getting extra excited.

Step 4: Roof

The boys absolutely refused to get down from the roof and surrender the hammers :D

After the main roof beam, first pair of roof beams were ready to go in. Once the first pair was OK, I pre-cut the other pairs.

First piece of plastic anti-vapour barier went in. as it would be tricky to add later on.

Here I noticed a bug - I had to make the external wall corners stick out to hold the last pairs of roof beams. It was a challenge to fix last beams of the roof :/ Anyway, live and learn.

Added extra metal brackets to hold the roof beams.

Foam panels went in next. Again, two wooden "spacers" were a great help to align the beams perfectly.

Once done, a layer of wind-proof film (black) went in, fixed in place with wooden strips. This is not really the correct way. For a house roof, there should be another layer of wooden strips on top of it.

A layer of green OSB panels (damp resistant) went in, as bitumen shingle roofing requires an even background.

Added a layer of bitumen coating just to be extra sure. Again, the cost of it was minor, extra protection-relevant.

Added bitumen shingles, as I've only had experience with those & didn't want to cut metal sheets or do clay tiles, etc.

Added metal corners to roof beams, also metal rainwater guides on the sides.

Step 5: Insulation, Wind and Vapour Proofing

Insulation, wind, and vapor proofing came next.

Black is anti-wind. You use it to prevent wind and vapour from getting in. It also allows vapour to escape the internal wall "sandwich" structure. Thus, you'd leave a small gap between the black film and the final wall cladding. This allows the wind to remove the excess humidity.

Silver film is a strengthened (plastic mesh inside) vapour barrier, that protects the insulation from the vapour from inside getting into the wall insides.

The seems are connected with a sticky tape.

Any wood-to-foam gaps were filled with expanding foam (low-pressure point).

Rockwool insulation went in. Again, when building wall structures, exact wooden "spacers" proved to be super useful. You measure the wall segments to be the exact size of the rock wool sheet.

The internal film was sealed using tape.

The weather down here gets up to -30 celsius in the winter. Hopefully, 10 cms of rock wool will help somewhat.

The build was ready for wood cladding.

Step 6: Wood Cladding, Inside + Outside

It really helped to plan the space with typical construction lumber lengths - 3 meters in this case. Saved time on cutting and waste.

Outside wooden siding, much thicker, Nordic wood.

Thin wooden strips went in, leaving ~2,5cms gap between the anti-wind film and the wooden siding.

Wooden panels inside went in. Working with your hands raised above your head is a b*tch.

Bought the door at the local "home depo", which has some 2 cms of foam inside to help with the heat escape.

Painted. Color name: amber teak.

Crafted, screwed, and painted edgings for doors and windows, also corners. Also windowsills for the inside windows.

It was time to work on the interior.

Step 7: Interior: Flooring, Furniture, Workspace

So, having a mid-life crisis full-on, I've wanted an IKEA swinging armchair. Some buy Ferraris, and some - chairs from IKEA ;)

Added panel flooring.

Moved the European map from my Travel trailer instructable inside. That one is getting transformed.

Bough a decent-looking chair. You know, after 40, all's left is diets and backpains :D

I bough two wooden panels and two table legs and after some time and quite a bit of cursing managed to craft a half-decent table.

Added wooden strips to hide all the joints.

Moved in my good-ol' Ender 3 pro.

Added window cover, as the sun was making it tricky to work in the afternoon.

Added extra lamp to the ceiling. The switch is hidden behind the 3D printer.

Step 8: Interior: Decoration

To make it more fun, we dedicated one wall as a diary of family trips. Slowly filling it with the previous travels.

You can see our trip in Poland during the school spring break this year (Bialystok, Warsaw, Gdansk, Wolf's Lair)

As true tourists, we now have space for all the fridge magnets :D

3D printed some small add-ons. I will print the Eye-of-Sauron for the Russia.

Added a shelve for the books to look intelligent and pretend I actually read them (or know how to read :D )

Step 9: Interior: Heating Stove and Chimney

Chimney was quite a chore. Got sold wrong set of parts at the DIY store, had quite an annoying day assembling the bastardly device. Anyways...

Anti-fire protection requirements says the chimney has to be distanced both from the walls and the internal wooden structures.

Thus, two sheets of inflammable material went onto the wall.

Ordered two steel sheets for that.

Bought a small 4KW heating stove for the rainy and cold seasons . As we joke, we have 2 weeks of summer here, the rest is just bad weather ;)

Made a small "table" below the chimney to hold the main weight of it. Also tried to fix the whole contraption using a metal ring.

Fire. Nice. Warm. Surprisingly, almost no smoke went inside while igniting. I must be getting new skills :D

External chimney is double layer insulated one, as it prevents most of the tar accumulation inside. Insanely expensive as well.

Step 10: Exterior: Outside Views + Decorations


Lock on the doors.

Flowers as a modern camouflage for the dad-cave.

The cross is an interesting historical symbol for my country, as it's a sun-cross, uniting the animist and Christian periods for my country. There are ideas of adding other related small cultural symbols on the wall below.

Yes, that wall section is lighter on paint on purpose. Helps attract the gaze and see less of my misadventures while constructing the building ...

Step 11: Walkway

There was a nasty gap separating a previous terrace and the building. Thus, we constructed a small walkway. It also helps to have shoe pad, as dirt transfers fast from the garden.

2x4s, nothing fancy.

Step 12: Semi-Final Result, DOs, DONTs, Budget Thoughts

Tried to take a photo of each corner. The building still needs small touches here-and-there.

Some insights learned.

What's good

  • The roof doesn't leak ;)
  • Quite a good sound insulation.
  • Decent amount of light passing in.
  • Significant improvement to the work quality compared to previously. Much greater ability to focus and perform.


  • All family members are eyeing this one, for a sleep-over, new playground, and new space for hobbies. My cave is already getting invaded. Need more doors :D
  • Some of my decisions might appear over-engineered, but, being an amateur self-taught builder, this is the only way I know/googled how to do things.
  • Build budget +30% over the initial plan. Stuff costs €. Especially with the bloody Ruskies invading neighbors around here.
  • The middle kid is insisting on his own similar place now. Oh, what have I unleashed...


  • When planning, aim to build to the same/similar lengths as a typical length of construction lumber. Here it's 3m; 2,40m; 6 meters.
  • In warmer climates, a simple electrical heater might be enough. This would save a significant part of a budget and quite a few headaches.
  • Re-using available materials (windows in my case) is a good way to go.
  • When planning, think ahead, if/how/when the space can be transformed according to changing family needs. We strongly considered turning this into a sauna once the kids move out.


  • If possible, do not over-save on materials. You'll save a small part of a budget, but the overall experience might suffer considerably.
  • Do not use a 3D printer where you work/sleep. The output fumes are nasty. I plan printing at night only and ventilating sufficiently in the morning.

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