Off-Grid Design Lab

a place to tinker, in dialogue with the land

Experiments in building, planting, art and open-source instruments on a regenerating hectare in the Minho, shared so others can learn from them.

Everything on this land was designed here and built by hand, from what the valley offers and what we could salvage. For each project we sketch, build, test and adjust, then write down what we learn.

Each season more hands come back. Pouco a pouco, A Corujeira is becoming a home for a small collective of artists and tinkerers.

Each project has its own page with the method, the materials, what we learned along the way and, where there is code, a link to it. All of it is open, so another small project can start from where we are.

Principles

Learn by making, teach as we go. We ask how to move as much knowledge as possible through as many hands as possible.
Do it ourselves. We design, build, repair and document what the land needs, and share how, so others can do the same.
Built from what's at hand: local timber, clay, stone and salvaged parts.
Solar-powered and low-energy.
Local-first: the instruments keep working without the internet.
Open, and documented for non-specialists.
Honest records: fixed methods, logged changes, open data.
Shared with the bioregion.

How we measure

We keep records over years with fixed methods, log every change, and open the data to anyone who wants to check it. Pouco a pouco, the records show whether the regeneration is working.

An invitation

We welcome ecologists to review our methods, funders to help grow these tools into a regional network, and neighbours who would like an instrument of their own. Artists, tinkerers and gardeners are invited to come for a season, build and plant alongside us, and help shape what this collective becomes. Many of our builds and plantings become open workshops, and there is a place in them for you.

Code on GitHub Substack Instagram

Instruments and tools

Solar-powered, home-built and open source. They watch for fire and track water and sunlight. The data stays on the land, and the instruments keep working when the satellite internet sleeps.

Running

Vigia

the fire watch

Official fire risk, live incidents and satellite heat, gathered into one early warning for the valley.

Read more2026

Running

Land dashboard

the land at a glance

The kitchen tablet: the silo's level, the sun and batteries, the air in the yurt, and a land avatar who turns it all into plain advice.

Code2026

Running

Herb garden guide

a conversation with the garden

A guide to the 39 herbs of the medicinal garden, drawn from a trusted canon of traditional Western herbalism.

Visit2026

Identifying a surveyed plant with PlantNet in QGIS

Running

Plant mapping

every plant, to the centimetre

Each plant on the land is located with GNSS to the centimetre, photographed in place, and identified through a Pl@ntNet plugin for QGIS, with a person confirming every name.

Read more2026

Buildings

Small structures of timber, clay, stone and reclaimed material, each one a lesson in building with the place.

The owl-shaped barrel sauna among ferns and oaks

In use

The Sauna

the owl by the waterfall

An eight-person wood-fired sauna in Japanese cedar, modelled in Rhino, prefabricated over months, and shaped like an owl.

Design Eska · Built with Omali and Damien

Clayhouse

a woodshed turned to clay

A tiny house of local clay and straw on a frame of the land's own eucalyptus, with salvaged windows and roof panels and solar on top.

Design Eska · Clay work with Lea

Page coming2025

In use

Workshop

the makerspace

A sheltered bench with power tools, built in 2025 to give every other project a place to start.

Page coming2025

3D model of the reciprocal arch woodshed on its pallet deck

Built

Da Vinci woodshed

a reciprocal arch for firewood

A self-supporting reciprocal arch after Leonardo, woven from cryptomeria boards ripped into strips and raised on five Euro pallets. Its geometry was programmed before the first cut.

Read more2026

A timber room in the oak canopy under a vaulted roof, lit by a lantern

In use

Yurt extension

a gable that cuts into the circle

An experimental timber addition that cuts into the yurt's round plan, with a vaulted roof whose ridge runs back to the yurt's crown.

Read more2026

A small A-frame of charred timber with an almond-shaped window, on a wooded hillside

In use

The poop shrine

a compost toilet

A compost toilet built entirely from scrap wood, clad in charred yakisugi boards and roofed with salvaged flashing.

Read more2026

Land

The slow work of recovery after fire: replacing eucalyptus with a diverse, fire-resistant food forest, growing a garden beneath the oaks, and planting medicine on the terraces.

Growing

Living firebreak

the young food forest

Seventy eucalyptus felled on contour beneath the power line, and more than 200 trees, shrubs and cuttings planted in their place.

Page coming2025

Growing

Medicinal garden

terraces above the creek

Terraces above the creek planted with more than twenty species of medicinal herbs.

Page coming2025

Starting

Woodland garden

a garden beneath the oaks

Contour beds built from oak prunings to hold the terraces, planted with shade lovers and flowers for pollinators.

Read more2026

Art and objects

Sculpture, light and living structures, made with other artists and makers.

Growing

The trellis

a living portal

A metal trellis sculpture at the way into the land, planted this autumn with a grapevine that should cover it by next year, in homage to the land's history.

By Jannis

Page coming2026

A ribbed wooden lantern lit and hanging by a window

Building

Lanterns

a fire that listens

Seventeen half-lap plywood lamps, sketched by hand, modelled in Rhino and laser-cut, now growing into programmable fire lanterns of 266 LEDs that respond to music.

Design Eska · Mechatronics Anca

Read more2026

Made with

Some of the work here is made together with other artists and makers. These are the collaborators whose work lives on the land.

Jannis

Metalwork

The trellis

Anca

Mechatronics

Lanterns

Omali and Damien

Building

The Sauna

Lea

Natural building

The Clayhouse

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Instruments and tools

Vigia

the fire watch

A fire lookout for a remote valley, bringing official fire risk, live incidents and satellite heat into one early warning.

Status: Running since October 2026
Runs on: Home Assistant, on the land
Cost: Free; two optional free keys
Power: No extra hardware
Licence: MIT
Code: acorujeira/ha-vigia

Vigia's fire map: alert rings around the land, a satellite heat detection, burnt areas from past seasons, rivers and creeks — Vigia's fire map: alert rings around the land, a satellite heat detection to the north-east, burnt areas from past seasons, and the rivers and creeks of the valley.

Why it exists

Vigia is Portuguese for a fire lookout.

About two decades ago a fire burned through this valley, carried by the eucalyptus plantations that still cover much of the Minho. In the summer of 2025 we watched the Gerês range burn from the hill above the yurt, ridge after ridge lit orange in the dark. Fire season here is part of the year, and living with it well means knowing early.

The information already exists, scattered across several places. IPMA publishes the daily fire risk for each concelho. Civil protection reports incidents to Fogos.pt. NASA's satellites pick up heat from orbit. The wind decides where any of it goes. Checking all of that on a phone, over a satellite connection, in the middle of the night, is how warnings get missed.

Vigia gathers these sources in one place on the land and speaks up only when a fire is close or heading our way.

What it does

A fire tile on the kitchen dashboard shows today's and tomorrow's fire risk on a five-step meter, any weather warning, how many fires are nearby, and plain advice when the risk is high.

A fire map covers 30 km around the land. Satellite heat is drawn as fire footprints, each one bright at the newest front and fading over 48 hours, like growth rings. Incidents appear with their status, alongside this season's burnt areas, the creeks of the valley, wind arrows, and the upwind sector shaded.

Alerts come in three tiers, each adjustable.

Any fire within 2 km, whatever the wind.

Urgent: breaks Do Not Disturb and flashes the lamp-post lights.

Upwind

Within 5 km, with the wind blowing from the fire toward the land.

Urgent: breaks Do Not Disturb and flashes the lamp-post lights.

Watch

Within 15 km upwind, with wind of 20 km/h or more.

A normal notification.

Each fire alerts once, and again only if it moves up a tier or comes more than 1 km closer. Satellite detections older than 12 hours never raise a new alert.

How it works

Vigia is an open-source integration for Home Assistant, the platform that already runs the land's off-grid systems. Home Assistant fetches each source on its own schedule and keeps the results on site, so the tile, map and alerts carry on from the last data if the internet drops.

Source	Gives	Refresh
IPMA	Fire risk today and tomorrow for the concelho; weather warnings for the district	60 min · 15 min
Fogos.pt	Active incidents reported by civil protection (ANEPC), often faster than satellites	5 to 15 min
NASA FIRMS	VIIRS satellite hotspots, up to about 3 hours behind	10 min
EFFIS	This season's burnt areas, © Copernicus	6 h
Open-Meteo	Wind across the map	30 min
OpenStreetMap	Rivers, creeks and lakes	30 days
The land's weather	Wind at home, for the alert rules	live

A satellite hotspot can also be a sunlit roof or a farmer's burn, so satellite alerts say "heat detected" and point to Fogos.pt to check.

Vigia is a helper. Official advice from ANEPC and local civil protection always comes first.

What we've learned

Two kinds of data cover each other's blind spots. Civil protection reports often arrive first; satellites see fires nobody has reported yet.
Alerts need restraint. A tool that cries wolf gets muted, so each fire speaks once unless it gets worse.
Fogos.pt is a volunteer project. Vigia asks each user to request their own free key, polls gently, and credits the source.
Fire risk is published per concelho, and near a border the nearest one can be the neighbour's.
A pretend fire is the button we use most. Test mode places one upwind of home, so the tile, map and alerts can be tried safely.

Make your own

Vigia suits anyone in Portugal running Home Assistant. Fire risk, warnings and incidents are Portugal-only for now; satellite heat, burnt areas and wind work anywhere.

Add the repository to HACS as a custom integration and download Vigia.
Restart Home Assistant and add the Vigia integration.
Request the two free keys, from Fogos.pt and NASA FIRMS, and choose your weather entity.
Add the fire tile to a dashboard, and create alerts from the Vigia blueprint.

Install guide on GitHub

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Instruments and tools

Plant mapping

every plant, to the centimetre

A living map of the land's plants: each one located by GNSS, photographed where it grows, and named through Pl@ntNet inside QGIS, with a person confirming every name.

Status: Running since October 2026
Runs in: QGIS 3.28 to 4.x
Identification: Pl@ntNet API, free key
Position: Centimetre GNSS survey
Version: 0.3, experimental
Code: Opening soon on GitHub

The plugin panel in QGIS: a photo of a clary sage rosette from point 23 of 59, with Pl@ntNet candidates listed below, Salvia sclarea first at 85.6 percent — Point 23 of 59 from the October 13 survey. Pl@ntNet suggests clary sage, *Salvia sclarea*, at 86 percent, and the name waits for a person to confirm it.

Why it exists

Restoration asks for a memory. Which saplings from the Owl's Nest planting took hold, which guilds are thriving, where the eucalyptus is returning: the answers live in hundreds of small plants spread across steep terraces, and a notebook loses track of them within a season.

A map that knows each plant by place and by name lets us return to the same oak or hazel year after year, see how it grows, and plan the next planting around what the land is already doing.

How it works

Survey. Walk the land with a GNSS receiver and record each plant's position to the centimetre, with a photo taken in place.
Browse. In QGIS, step through the survey point by point. The plugin shows the photo attached to whichever point is selected on the map.
Identify. Send that photo to Pl@ntNet and receive a ranked list of candidate species with their confidence.
Review. Choose a candidate and confirm that the plant stands at the surveyed point. Only then is the name written to the map.
Plan. Look up the species' typical mature canopy, so future plantings can be spaced for the trees they will become.

Care for the record

The plugin adds the reviewed name beside the survey data and leaves the original coordinates, GNSS quality, source ID and photo path as they were. Every change sits in QGIS's edit buffer, so it can be undone before saving.

Each identification stays bound to the exact point and photo it came from. If the selection moves while Pl@ntNet is answering, the late answer is set aside.

Canopy sizes come from published width ranges for each species, using the midpoint as a planning figure and keeping the source link alongside. These are starting points for spacing; pruning, cultivar and competition in a young woodland all shape the real tree, and local measurements will refine them over the years.

What we've learned

Pl@ntNet is a strong first opinion. Close relatives can look alike in a single photo, so a person signs off on every name.
A photo shows where the camera stood. The GNSS point shows where the plant grows, and the review step asks for both to agree.
Planning figures need their sources attached, so anyone can check where a number came from.

What's next

Publishing the plugin as open source, with a setup guide for other land projects.
Canopy figures for more of the species planted in the food forest.
A yearly resurvey, to follow each plant's growth over time.

← Off-Grid Design Lab

Land

Woodland garden

a garden beneath the oaks

A layered garden under the oak canopy, grown on contour beds built from the land's own prunings to hold the terraces through the winter rains.

Status: Starting autumn 2026
Planting: Winter 2026 to 2027
Beds: On contour, 0.8 to 1 m wide
First phase: 40 to 60 m of bed
Built from: Oak prunings, soil, compost
Light: Shade under oak canopy

Why it exists

The oaks on the lower half of the land came back thickly after the fire, and years of thinning and caring for them have left piles of prunings. The terraces beneath them lose soil every winter as the rain runs over their edges.

The woodland garden puts the two together. The prunings become the body of new beds along the contour, and the beds become a home for plants that thrive in the shade.

What it's for

Holding the soil. Beds and plantings along the terrace edges slow the winter rains and keep the topsoil where it is.

Life beneath the oaks. Shade-tolerant species and flowering ornamentals bring pollinators and more diversity into the understory.

A cooler, moister floor. Groundcover and mulch shade the soil, building a low microclimate close to the ground.

Feeding the beds. A worm farm under the shelter of the oaks turns green waste into castings for the garden.

How a bed is built

Each bed sits on a mostly level terrace top, low and wide, and connects down into the mineral soil.

A contour bed in section. Partly decomposed branches sit at the base, packed with finer prunings, then topsoil, mineral soil and compost, then a layer of clean aged mulch.

Woody material settles as it breaks down, so permanent trees stay off the deepest wood. The first bed is a short pilot of 3 to 5 metres. We watch it through heavy rain, and if it holds, the beds grow along the terraces.

What will grow

The aim is a lush, layered understory that feels almost subtropical while suiting local shade, dry summers and the winter. Under the canopy there is very little frost, which widens what can grow.

The palette leans on shade lovers: fatsia, farfugium, hardy ferns, perennials and groundcovers. Nitrogen fixers go only into the brighter openings.

A nursery started this autumn is raising the first plants: geraniums, hydrangeas, ferns, shade perennials, vetiver slips and winter green manures.

Timeline

October 2026. Map the area, sort the prunings, start the nursery and the worm farm, and build the pilot bed.
November. Scale the beds if the pilot holds, prune, and begin autumn planting.
December. Check the beds after the rains, label, take stock of the nursery and update the map.
Winter into 2027. Plant out the woodland garden, then add drip irrigation and widen the planting through spring and summer.

← Off-Grid Design Lab

Buildings

Da Vinci woodshed

a reciprocal arch for firewood

A self-supporting arch after Leonardo, woven from short cryptomeria strips and raised on five Euro pallets to keep about 4.5 m³ of firewood dry.

Status: Built 2026
Span: 3.8 m
Height: 2.25 m, 1.87 m clear inside
Depth: 1.2 m
Timber: Cryptomeria, 45 × 70 mm strips
Base: Five Euro pallets

3D model of the woodshed: three families of bars woven into an arch over a deck of five pallets, tied together by runners — The arch modelled before cutting. The three colours mark the three families of bars that weave over and under one another.

Why it exists

The sauna and the yurt's wood burner run on firewood, and firewood seasons best somewhere dry with air moving through it. The woodshed gives it that, on a deck of pallets that keeps the stack off the ground.

Leonardo da Vinci sketched bridges made of short, straight timbers that lock together under their own weight. The same idea, now called a reciprocal frame, makes a strong arch from the kind of short stock a small workshop can cut and carry.

How it works

Each frame of the arch is built from short bars. Every bar rests on its neighbour and carries the next, so the load travels round the arch through a woven pattern of supports. Eight sections make the curve.

Runners laid across the frames tie them together along the depth of the shed. Each runner has a small notch cut under each end, 10 mm wide and 4 mm deep, which catches the edge of the bar it sits on and stops it sliding.

The geometry, programmed first

Before any timber was cut, the arch was worked out in a small tool. It takes the number of pallets, the span, the depth, the number of sections and the size of the timber, then draws the arch and gives the length and notch position of every piece. Changing one number redraws the whole thing.

The number of sections sets the height. The shed uses eight, which gives 1.87 m of clear height inside. Each joint bends the arch by 22.3°, and together they sweep through 178°, a little short of a full semicircle.

Runner drawing: 1,600 mm long, 72 mm deep, with a 10 by 4 mm notch under each end — A runner drawing from an earlier layout, with its notches marked for cutting.

Dimensions

Span	Between the centres of the two foot cross bars	3,800 mm
Depth	Front to back, one pallet deep	1,200 mm
Overall height	From the ground	2,246 mm
Clear height	Above the deck, under the crown	1,872 mm
Widest point	Outside the arch	3,870 mm
Sections	8, bending 22.3° at each joint	178° sweep
Runners	14, notched 10 × 4 mm under each end	1,581 mm
Foot starters	The same part at both feet	861 mm
Cross bars	9, plain	1,500 mm
Deck	Five Euro pallets in a row	4,000 mm
Timber	Seven 300 × 45 × 3,000 mm boards, about €145	0.28 m³
Firewood	Stacked three rows deep, about 1,600 pieces	4.5 m³

Build

Lay five Euro pallets in a row as the deck, 4 m long.
Rip seven 45 × 300 mm cryptomeria boards into strips 70 mm deep, four to a board.
Cut 14 runners, the foot starters and 9 cross bars to the lengths the tool gives, and cut the notches under the runner ends.
Raise the arch on the deck frame by frame, and lay the runners across.

The build

The bare reciprocal arch frame standing on its pallet deck in front of a dry stone wall — The frame standing on its deck, before cladding.

The arch frame seen from the side, showing the bars weaving over and under one another — From the side, the bars weave over and under one another.

The woodshed clad in overlapping boards, with a ladder and a pile of firewood in front — Clad, with the first firewood waiting.

Make your own

The arch tool is open source. Set your own pallets, span, depth and timber, and it gives you a 3D model, the part drawings, a cut list and a printable build sheet. The defaults are the shed we built.

It calculates geometry only. Check the structure separately before you build.

Open the arch tool Code on GitHub