Is AI worth it in a small office? A calculation with assumptions

Whether AI is worth it in a small office can be calculated, but only with assumptions that you disclose. On one side are the licence or platform, set-up, training and upkeep, plus the checking time. On the other side are the hours that no longer arise in preparing and drafting, valued at your hourly rate and reduced by the share you actually use differently. The figures below are invented. They show the way of calculating, not your result.

The cost side

Four items belong on the left.

• Licence or platform: running costs per month, which differ with the mode of operation (a service within the EU, your own server). Enter the value from a quote, with the date. For an idea of what automation projects cost, see What does an automation project cost? Prices with date.
• Set-up: a one-off cost, for example for connecting the filing system, templates and first tests. Spread the amount over the months you want to use the solution.
• Training: working time of those involved, valued at the hourly rate. The example uses 3 hours per person (kick-off, role module, follow-up session a few weeks later). The article AI training by role: content for the office and the site gives 3 to 4 hours. Under Article 4 of the EU AI Act in its 2026 version, providers and deployers of AI systems take measures to support the development of the AI literacy of their staff. They do not have to guarantee a particular level for any individual. Whether and how that affects your office is for your legal adviser to clarify.
• Upkeep and checking: keeping templates up to date, checking results by sample, adjusting rules. The German Federal Office for Information Security (BSI) points out that, besides opportunities, generative AI models bring new IT security risks. Anyone who takes that seriously plans time for it.

The benefit side

The benefit is the time a workflow costs less. Calculate it per workflow: cases per month times minutes saved per case. How you establish the cases and minutes is described in Measure workflows before introducing AI: log one week, and how to compare before and after in Measuring time savings: cases times minutes, before and after.

What counts is what you enter as saved. In meeting minutes, the note-taking arises as long as the meeting lasts. Time can be saved only before and after: in preparing from the last set of minutes and in writing up. More on this in Meeting minutes with AI: from recording to sign-off.

The checking time stays. A draft from the AI has to be read, compared with the documents and approved. In the example calculation, the line “Writing up incl. check” therefore shows not zero but half of today’s time.

Example calculation with invented data

An office has six project leads, and each writes two sets of meeting minutes a week. That is 12 per week and, counting four weeks to a month, 48 per month. The times per set of minutes are the author’s working assumptions, not measured: 30 minutes of preparation, 90 minutes of note-taking and 120 minutes of writing up, 240 minutes in all.

todaywith AI

• PreparationAssumption, 30 % less

  today 24 h
  with AI 16.8 h

• Note-takingMeeting time, stays

  today 72 h
  with AI 72 h

• Writing up incl. checkAssumption, 50 % less

  today 96 h
  with AI 48 h

• Upkeep of the solutionAssumption, 2 h a month

  today 0 h
  with AI 2 h

Source: Invented example data, the author’s working assumption, not measured

Text version of the graphic

• Preparation: today 24 h, with AI 16.8 h (Assumption, 30 % less)
• Note-taking: today 72 h, with AI 72 h (Meeting time, stays)
• Writing up incl. check: today 96 h, with AI 48 h (Assumption, 50 % less)
• Upkeep of the solution: today 0 h, with AI 2 h (Assumption, 2 h a month)
• Source: Invented example data, the author’s working assumption, not measured

The AI variant rests on cautious assumptions. Preparation becomes 30 per cent shorter, writing up including checking 50 per cent shorter, and note-taking stays the same. Both values are below the ranges the calculator uses (30 to 50 per cent for preparation, 60 to 75 per cent for writing up). That saves 9 minutes on preparation (30 per cent of 30) and 60 minutes on writing up (50 per cent of 120), 69 minutes per set of minutes in all. With 48 sets of minutes that is 55.2 hours a month.

Which hourly rate?

The example values every hour at 100 euros. This means full cost per project hour: the cost a business bears for one working hour of an engineer or project lead, including overheads such as premises, administration and software, but excluding profit and VAT. The 100 euros are an assumption of the author, supported by two surveys from chambers and professional associations.

The first survey comes from the Federal Chamber of Architects (Bundesarchitektenkammer). It determined what hourly rate an office has to earn per project hour to cover its costs (total costs including the owner’s salary, divided by project hours). For offices without a loss and with at least ten people working in them, the median was 81 euros in 2021. The Federal Statistical Office puts labour costs per hour for the economy as a whole at 36.8 euros for 2020 and 45.00 euros for 2025, a rise of 22.3 per cent. Updating the 81 euros with that gives 81 times 1.223, about 99 euros. That is rough, because the rise covers all sectors together.

The second survey is the member survey by IW Consult for four professional associations (reporting year 2024). For engineering practices with more than 10 and up to 50 employees it gives an overhead factor of 1.9. Multiplied by the pay of the people working on projects, it gives the rate that covers all overheads. For pay I use about 54 euros an hour (my assumption: median salary of a civil engineer plus employer contributions, not retrieved again). That makes 1.9 times 54 euros, about 103 euros.

Both routes give 99 and 103 euros, rounded 100 euros. Three limits apply. Both surveys rest on self-reporting by architectural and engineering practices, not by construction companies or property administrations. The chamber figures come only from offices without a loss. The 99 euros are updated, not measured. Your own cost accounting decides.

These must be told apart from the labour costs of the Federal Statistical Office. According to the 2024 labour cost survey, an hour worked cost 44.32 euros on average, and 52.87 euros in professional, scientific and technical services, which include architects’ and engineering practices. Overheads and time without project work are not in it, so full cost per project hour is higher.

Item	Assumption	Euros per month
Platform (placeholder, not a vendor price)	400 euros a month	400
Set-up	3,000 euros one-off, spread over 24 months	125
Training	6 people, 3 hours each at 100 euros = 1,800 euros, spread over 24 months	75
Upkeep by the office	2 hours a month at 100 euros	200
Total cost	400 + 125 + 75 + 200	800
Time gained on paper	55.2 hours at 100 euros	5,520
Of which actually used differently	Assumption 50 %	2,760
Result	2,760 minus 800	1,960

Half as a rate is a stipulation without measurement. It allows for the fact that minutes arise scattered and not every one becomes a usable hour. With this assumption, 1,960 euros a month are left in the example. The solution pays for itself as soon as about 14 per cent of the time gained on paper is used differently: 800 divided by 5,520 is about 14.5 per cent.

The counter-test

A calculation that only looks good says little. So check what happens with worse values. If the saving on writing up halves to 25 per cent, the minutes gained per set of minutes fall to 39 (9 minutes of preparation plus 30 minutes of writing up). That is 31.2 hours a month or 3,120 euros, or 1,560 euros at 50 per cent use. After deducting 800 euros, 760 euros remain. If the rate of use also falls to 20 per cent, the figure is 624 euros, which is 176 euros less than the cost. With the weaker saving, the solution pays for itself only from a rate of a little over a quarter (800 divided by 3,120 is about 26 per cent).

CostBenefit used

• Base casePlus 1,960 €, 50 % of time used

  Cost 800 €
  Benefit used 2,760 €

• Writing up: only 25 % savedPlus 760 €, 50 % used

  Cost 800 €
  Benefit used 1,560 €

• Plus only 20 % of time usedMinus 176 €, does not pay

  Cost 800 €
  Benefit used 624 €

Source: Invented example data, the author’s assumptions, rate 100 €, not measured

Text version of the graphic

• Base case: Cost 800 €, Benefit used 2,760 € (Plus 1,960 €, 50 % of time used)
• Writing up: only 25 % saved: Cost 800 €, Benefit used 1,560 € (Plus 760 €, 50 % used)
• Plus only 20 % of time used: Cost 800 €, Benefit used 624 € (Minus 176 €, does not pay)
• Source: Invented example data, the author’s assumptions, rate 100 €, not measured

The result therefore hangs on two numbers: how much time the workflow really saves and how much of it you can use differently.

What you may not count

• The checking time. It stays as long as a person approves.
• The note-taking in the meeting, the conversation time itself and waiting for replies.
• The full sum of minutes as euros if nobody uses the time gained differently. Anyone who does not turn it into orders, fewer overtime hours or work that was left undone has gained hours but no money.
• Values from vendor brochures or from offices you do not know. There are no independently measured figures for your workflows. Your own measured values replace the assumptions above.

Whether a service meets the requirements for data protection and confidentiality belongs before the calculation. Anyone who puts project data into a consumer chat service has a different problem from profitability; see Shadow AI: when staff use private chat services. A rule for the office is described in AI policy for the office: what it should contain. Which working-time and co-determination questions arise when measuring is for the data protection officer, the works council and legal counsel to clarify in the individual case.

What you can do now

1. Measure one workflow for a week: cases, minutes per case, separated into preparation, handling and checking.
2. Obtain two quotes for the cost side and enter price and date in your table.
3. Calculate as above, with your own hourly rate and a cautious rate of use, and test the calculation with worse values.
4. Only then decide whether a trial of four to six weeks is worthwhile, and measure again afterwards with the same log.