Draw it once
Plot boundary, buildings, storeys, rooms, walls, doors, windows, the roof with its sections and skylights, the runs of pipes and cables — in flat editors that measure in millimetres. The 3D model follows every stroke.
A hobby project
I built a digital twin of my house. You can use it too.
Domitwin started as a tool for my own home: every storey, room, window and the roof drawn to measure and shown in 3D, with what I know about the house hung on it — what was done when, what comes due, where the manual is — and my Home Assistant sensors in the rooms they belong to. It is online now for anyone who wants to try it. Free, and one person maintaining it.
See it whole
Fly from the plot into a building, lift the storeys apart, step into a room. Tap anything to open its page. On a phone as well as on the wall tablet.
Keep what you know
Every room and every thing has a history: what was done, when, at what cost, with the invoice attached. Recurring duties tell you what comes due. Documents and photos hang where they belong.
Connect Home Assistant
Put Home Assistant’s sensors and switches on the rooms they are in — temperature, humidity, the light — with graphs over time, and a kiosk view of the house in 3D for a dashboard or the tablet on the wall.
What this is, and what it is not
A side project by one person, built for one house and shared because others asked. It works, it is used every day, and it will keep changing — the changelog says how. There is no company behind it and nothing to buy.
Your data stays yours: everything you draw and write can be exported as an archive at any time, and deleting the account deletes it all. If something breaks or you have an idea, the blog and GitHub are where to say so.
Questions
Is it free?
Yes. It is a hobby project; there is nothing to buy. Up to three properties per account — the house you live in, and a couple more.
Do I have to draw the whole house?
No. Start with the rooms you care about; a plot with one building and one storey is already a model. The sample house shows what a finished one looks like.
Where is my data?
On a server in the EU. You can export a whole property as an archive at any time and take it elsewhere; deleting your account deletes everything.
Does Home Assistant have to be reachable from the internet?
Yes: Domitwin dials your Home Assistant from its server with a long-lived token you create. Nabu Casa’s remote address or your own reverse proxy both work. The token is stored encrypted.