The construction log is one of the oldest documents in Slovak construction. For decades it was kept by hand, on paper, with all the drawbacks that brought, smudged entries from rain, lost pages, illegible signatures, complicated archiving. The year 2026, however, is different. The electronic form of the log is today fully recognized, anchored in legislation, and in practice often more comfortable than traditional paper. In this article we will explain the current legal requirements, what a fully featured digital log should look like, and why it pays to make the switch right now.
What Decree 453/2000 Coll. and the newer Building Act say
The basic legal framework for keeping the construction log remains Decree of the Ministry of the Environment of the SR No. 453/2000 Coll., which regulates in detail the scope and method of preparing construction documentation. The log must be kept from the first day of preparatory work until the handover of the building, and entries must be made every working day. Records must be legible, indelible, and signed by the responsible site manager. In parallel with this decree, the new Building Act 201/2022 Coll. is in effect, which introduced the Building Authority Information System (ISSU) and allows fully electronic management of project documentation, including the log.
The essential point is that the law does not mandate the paper form. The condition is to preserve integrity, authenticity, and availability of records. This is precisely where digital log tools come in, a qualified electronic signature (KEP) or advanced electronic signature (ZEP), together with a qualified time stamp, ensure exactly what the decree requires: proof of who, when, and what they recorded. And they do so more demonstrably than any pen on paper.
Tip: If you have doubts whether an inspector might pause your operations because of the electronic log, reach for a solution that generates a PDF/A output with embedded KEP and time stamp. Such a document is fully accepted at the building authority and in court disputes.
Electronic signature and time stamp, the heart of trustworthiness
Without an electronic signature, a digital log is not a log. A qualified electronic signature is, in the sense of the eIDAS Regulation (910/2014), equivalent to a handwritten signature and has full evidentiary weight in court. In Slovakia you most often create it using an ID card with chip (eID) or via a mobile app such as Slovensko v mobile. For site managers and construction firms, however, it is more practical to use a ZEP issued by a qualified certification authority such as Disig or NASES, you store the certificate in a cloud wallet and sign with one click from the mobile.
The time stamp is the second pillar. It proves that the record existed at a specific time and has not been altered since that moment. Without it, anyone could retroactively create a signed document and claim it was signed yesterday. A qualified time stamp from an authority like Disig or PostSignum costs cents per record and is attached automatically when the daily entry is locked.
The specific combination we recommend as a minimum:
- KEP or ZEP of the site manager at the end of every daily entry
- Qualified time stamp attached when the entry is locked
- Hash chain, every subsequent entry contains the hash of the previous one, so manipulation of the order is mathematically excluded
- Audit log of accesses and edits with IP address and user
A log secured this way has higher evidentiary value than paper, paper can never prove exactly when the entry was made.
Cloud vs. paper, five practical differences from the field
When we analyzed more than 50 Slovak construction firms, five points repeatedly emerged where the digital log simply outclasses paper.
1. Availability from the field. The site manager records directly via tablet or mobile. The entry can include photos, GPS coordinates, video from measurement, and a voice note. Paper handles only text and pen drawings, with the ink dissolving in rain.
2. Synchronization with the project manager and investor. In the cloud the investor has access to the daily state in real time. In the paper world the log rides for a week on the back seat of a car before it reaches headquarters.
3. Full-text search. Need to find when you ordered a specific steel? In a digital log you press Ctrl+F. In a paper one you flip through 300 pages.
4. Integration with budget and BIM model. Hours worked tied directly to the budget. Photo documentation linked to a specific BIM model item. You simply cannot do this on paper.
5. Archiving for 10+ years. A construction log is archived for at least 10 years after building approval. Paper requires a climate-controlled storeroom, a digital entry costs cents per year in the cloud.
Tip: When choosing a digital log, ask about the export format. The minimum is PDF/A-2b with all embedded signatures. The ideal is an open archival format you can open even in 20 years without dependence on a specific vendor.
Three most common objections, and how to refute them
In practice we encounter three repeated concerns that prevent construction firms from switching. Let’s address them in turn.
“The inspector won’t accept it.” Not true since 2020. The Slovak Trade Inspection, building authorities, and courts all accept the electronic log as long as it meets the formal requirements, KEP/ZEP, time stamp, immutability. In case of doubt, you have stronger evidence than with paper.
“The site manager won’t be able to operate it.” Modern apps are designed for people who are not IT experts. The operation is comparable to WhatsApp, write, take a photo, confirm. A pilot at three companies showed that site managers aged 55+ adopted the app within three days and after a week did not want to go back to paper.
“It’s expensive.” Licenses for a digital log start at 9 EUR per month per user. A paper log with comb binding costs 40 EUR, you buy ten a year, plus printing, courier, and archiving, easily 1,500 EUR per year for a mid-sized company. The digital solution saves half and removes the risks of loss and illegibility.
How to deploy a digital log in 14 days
The transition does not have to be a big trauma. The proven procedure we recommend to our clients in construction looks as follows.
Week 1, preparation. Purchase KEP/ZEP certificates for all site managers (about 30-50 EUR per year per person). Choose a software solution with support for Decree 453/2000. Set up user roles, site manager, deputy, TDI, investor.
Week 2, pilot. Launch the digital log on one smaller construction project in parallel with paper. After 5 days, compare time and completeness of entries. After 10 days, turn off paper.
Ongoing. Use the prepared construction log templates that contain the prescribed fields, weather, workers, equipment, deliveries, TDI notes. The template guarantees nothing from the decree is left out.
What to check when choosing a solution
The market for construction apps is full. Before you pick one, ask the vendor about these six points:
- Does it support KEP and ZEP in the form of eID or qualified certificate? A non-qualified signature is not enough.
- Does it attach a qualified time stamp? And from which authority, Disig, PostSignum, another eIDAS-compliant one?
- Who is the data controller? Data residency in the EU is the minimum, ideally in Slovakia or Czechia.
- What is the export? PDF/A-2b or PDF/A-3 with signatures and time stamps.
- Does it work offline? A site manager on a remote construction site does not always have signal. The app must be able to record offline and synchronize on first connection.
- Does it integrate with your ERP or budgeting system? Data from the log belongs in invoicing, payroll, and reporting to the investor.
Benefits in numbers, what our measurements showed
We analyzed 12 construction firms that moved to a digital log between 2024 and 2025. Average results after 6 months:
- Site manager time on the log fell by 42% (from 45 minutes daily to 26 minutes)
- Late entries (subsequent additions) fell by 88%, the app pushes for closing the day on the same day
- Disputes with the investor fell by 31%, every entry is unambiguous, with a photo and time stamp
- Archiving costs fell by 94%, from 1,200 EUR per year to 68 EUR
ROI ranges between 3 and 6 months, depending on the size of the firm.
Conclusion, paper has burned out, the digital log is here
The construction log on paper had its purpose in the 20th century. In 2026 there is no longer a reason to keep it, the law does not require it, the court does not prefer it, the inspector does not appreciate it, and the site manager does not want it. A digital log with KEP and time stamp is today safer, faster, cheaper, and more comfortable. The question is therefore not whether to switch, but when.
If the topic interests you and you want to try a digital construction log without risk, request a 30-day free demo of Modulario Construction Log directly on our website. We will show you the specific setup for your company, take care of the migration from paper, and within two weeks you will keep your log fully electronically. Call, write, or book a slot, the first step toward digital construction is one email away.