What we’ve built to win the worlds biggest blockchain hackathon of 2018!

A self-conscious house: tracking its lifecycle, automating maintenance decision making and even improving itself!

Kevin Leyssens


As you already know by now, we as TheLedger won the Blockchaingers Hackathon 2018 track Digital Nation’s Infrastructure. A big shoutout to DutchChain and their partners for organising the most amazing, exciting and thrilling hackathon we ever participated! Thanks for this opportunity! If you are interested in the experience we had, just read our blog post “Blockchaingers hackathon 2018 | The aftermath”.

So let’s dive straight into our concept: “A self-conscious house: tracking its lifecycle, automating maintenance decision making and even improving itself!”.

Daemon Edifice: the rise of self-conscious buildings

Sounds likes a movie title right? Well, it’s our name for the self-conscious housing platform: Daemon Edifice. Why would we pick such a weird (and maybe dark) name? When breaking it down, it isn’t actually such a weird name. Let’s look up the definition of a daemon.

Type of program that runs unobtrusively in the background, rather than under the direct control of a user, waiting to be activated by the occurrence of a specific event or condition.

Our self-conscious house runs in the background while we are off to work, enjoying our free time elsewhere or even living in it.

When going back in time where Socrates was philosophising, he was talking to his ‘daemon’. He described this daemon as an inner voice frequently warning him against mistakes, but never told him what to do. It was always referred to as an impersonal “something” or “sign”. By this term, he seems to indicate the true nature of the human soul, his newfound self-consciousness. Quite spot on! So what’s the definition of Edifice?

A building, especially a large, imposing one.
A complex system of beliefs.

A mix of these definitions is what we have: A building which is imposing by its complex system (blockchain with smart contracts and AI in the future) for maintaining and improving its state, that runs in the background and is activated by certain events (new regulations, subsidies, …) by which it is self-conscious.

A building which is imposing by its complex system (blockchain with smart contracts and AI in the future) for maintaining and improving its state, that runs in the background and is activated by certain events (new regulations, subsidies, …) by which it is self-conscious.

Tracking its lifecycle

Nowadays the owner of a house has the full knowledge and history of his house through landowner registrations, (old) documents of annexe creations, documents proving the work that has been done throughout the years (new central heating, solar panels, isolations, …) and other documents.

Transferring the ownership of a house brings a lot of hassle with this current model. All these documents and knowledge need to be transferred as well to the new owner. When documents go missing, there is no real proof that a certain work has been done. Unless you break everything down, for example, to see if a certain type or thickness of isolation has been installed on your roof.

That’s why you have little to no insights into the real market value of your house.

Wouldn’t it be better that the house has all these documents and knowledge relating to itself? Of course! We thought the same thing and that’s what we made. Call it a ‘Digital Twin’ or even a ‘Digital Soul’ of your house. When new works are completed, a transaction will be invoked on the blockchain network along with the documents proving a certain work has been done on a certain day by a certain contractor verified by a certain owner.

I already hear you thinking out loud: “What about the proof of payment and protecting the interest of the contractor?”. We got that covered as well! The house has a wallet of its own, where the house owner can send some money to. Because the wallet is on the public blockchain network called Stellar, anyone can verify that a certain transaction (payment) is made to a certain wallet (or person) at a certain date for a certain amount for a certain work. When the transaction is made, an extra transaction is stored on the private permissioned blockchain network where we use Hyperledger Fabric for extra transparency.

Integrating Stellar, which is a public blockchain with Hyperledger Fabric, which is a private permissioned (enterprise) blockchain network.

So when transferring the ownership of the house, a simple transaction on the blockchain network is invoked where you revoke the right of the previous owner and grant access rights to the new owner. The new owner instantly has all the history (and thus life-cycle) of the house with all the documents to prove these works.

Automating maintenance decision making

Based on the data provided, the house can check for maintenance tasks. An example could be that the central heating system needs a yearly checkup and has a subscription. The house can pay this yearly subscription with its own wallet described above.

Customise the self-conscious house to your needs

When driving some cars, you can choose to put them in eco, normal, sport or other modes depending on your driving style on that day. An owner can do the same thing with its house. Depending on your budget and vision at a given time, you want to put the house in eco, budget or comfort mode.

Based on this customisation, the house will recommend other offers and subsidies. When in budget mode, the house will recommend the offer with the lowest price. In comfort mode, it will recommend the best price and quality (rating system of some kind) and in eco mode, it will recommend the most eco-friendly contractor. Same goes for subsidies, based on your preference, you will have other subsidies suggested.

Unfortunately, we could not implement this feature (the customising part) in the given time but wanted to share it with you guys.

Improving itself

Is this even possible…? Sure it is! As a house owner, you don’t have the time, knowledge or even access to know everything about old and upcoming regulations and subsidies for your house. Let the house handle it!

Let the house handle new regulations and subsidies and notify the owner when applicable.

New subsidy or regulation flow

Every time a new subsidy (or regulation) is submitted by the government (or regulators), the house will check if this new subsidy is applicable to itself. When this is a positive match, the house will suggest this new subsidy to the house owner.

Upon accepting this new subsidy, which is done by the house owner, the house will make an offer request which is submitted to the decentralised reversed auction marketplace where certified contractors can bid on the offer.

Once a certain time has passed, the house will recommend a certain offer depending on its customisation (eco, comfort or budget). It is up to the house owner to accept this recommended offer or a different one.

When an offer from a contractor is accepted by the house owner, an escrow contract is made between the house and the contractor. The contractor knows for sure that the house has enough money (Lumens on Stellar) to complete these works. This way the interest of the contractor is protected as well.

On completion of the work, the contractor and the house owner sign a transaction and the payment flows from the escrow to the contractor.

For more details about the implementation of Stellar in our PoC (Proof-of-Concept) you can read more in the upcoming article: “Stellar Escrow Smart Contract Development”. You can find the link to this article at the bottom.

More than just the self-conscious house

The self-conscious house was a big part of our PoC. But we did even more in 48 hours! What is a self-conscious house when it has no input or output to make these decisions?

NOTE: We only had 48 hours to develop our idea. The design was not our primary concerns for following dashboards.

Reversed auction marketplace

So we’ve built a reversed auction marketplace where certified (by the government) service providers and contractors can log in and see all the offer requests the houses have submitted. They can bid on these offer requests. When bid, an offer is sent to the house and with this offer, a transaction is stored on the Hyperledger Fabric blockchain proving an offer is sent by a contractor to the house on a certain date.

A reverse auction is a type of auction in which the roles of buyer and seller are reversed. In an ordinary auction (also known as a ‘forward auction’), buyers compete to obtain goods or services by offering increasingly higher prices. In a reverse auction, the sellers compete to obtain business from the buyer and prices will typically decrease as the sellers underbid each other.

Government dashboard for insights on subsidies

On top of that, we’ve built a government dashboard where they can manage and get insights of their subsidies. They can see how many of this particular subsidies have been issued each month and how many are declined. Every issued or declined subsidy is stored on the Hyperledger Fabric blockchain network. The total cost of this subsidy is immediately visible.

A map of the country with each province (or town) in a different colour (green, orange or red) is shown to get an insight on where this subsidy is popular.

And last but not least, they can see what impact this subsidy has on the total country. E.g.: They issue a new subsidy for solar panels. After a year this subsidy is granted 244 000 times. With each subsidy costing €200 makes the total ‘giveaway’ of the government €44.800.000,00. But because of this subsidy, the whole country now has an increase of 2% renewable energy through solar panels!

“What could be better than a machine for giving away government money.” - Vinay Gupta

Make my house self-conscious!

You don’t need any special IoT (Internet of Things) device to make it self-conscious with our platform when finished. Because of the documents provided it will know when to do the checkups. That’s the beauty of it!

A self-conscious ‘smart’ house without any ‘smart’ devices.

Of course, we will integrate the usage of smart IoT devices in the future and it’s included in our long-term vision. But it’s not a must to make it self-conscious. This way old houses can join rapidly without any upgrades, for whom this platform can have a lot of benefits.

The canvas of the Daemon Edifice

One of the deliverables of the hackathon, besides the working prototype, was a canvas where we needed to think about every aspect and impact of our idea. The result is shown in the picture below. Enjoy!

Interested in starting your own blockchain project, but don’t know how? Do you need help starting your token sale or having one audited? Get in touch.

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NEXT UP IN THIS SERIESStellar Escrow Smart Contract Development



Kevin Leyssens

Full stack blockchain developer and consultant at TheLedger.