Less admin, more engineering.

A subsidy project is mostly paperwork.

A homeowner or a housing association wants to renovate: insulation, new windows, a heat pump, sometimes the whole building up to an efficiency standard. The state pays part of it through the BEG programmes run by KfW and BAFA, but only if a certified energy consultant signs off on the plan before the work starts and on the evidence after it ends. Hölzl is that consultant.

Each project moves through the same sequence. A first conversation and a proposal. A visit to take the building in, room by room. Calculations, the technical confirmation the funding application needs, and a wait for approval. Then the works, a second visit on site, and the part nobody enjoys: collecting every invoice, bank statement and proof of payment, checking each line against what was approved, and producing the final confirmation.

Every step has a document due, a letter to send, a signature to collect or a deadline that quietly expires. Multiply that by five programme variants with their own rules and by dozens of projects in flight at once, and an office of engineers ends up spending its days on administration instead of on buildings.

What we built is not one tool. It is the office’s operating system: one record per project, and everything that has to happen at each stage hanging off it.

Stage		What happens	In flight
00	First meeting	Call or office visit. Proposal drafted from the meeting notes.	5
10	Proposal	Sent with the legal notices. Expires and archives itself if unsigned.	9
20	Order confirmed	Power of attorney signed, data-collection form issued, building survey booked.	14
40	Subsidy application	Technical confirmation prepared and filed. Approval awaited.	17
50	Works	Construction underway. Second visit on site.	9
70	Invoice	Invoices, statements and proofs collected and checked. Final invoice issued.	7
80	Declaration	Confirmation after completion signed and presented.	3
99	Complete	Project archived. A follow-up project can inherit its data and files.	156

Four parts, one system.

The pipeline, the documents, the screens and the money. Each was built for this office and shipped into a running one.

01One status change does the week’s admin.

Every project is a record with a status, and the status is the spine of the system. Twenty-one of them, numbered the way the office already spoke about them. When a project moves from 10 to 20, the order confirmation goes out with the right attachments, the power of attorney is pre-filled from the record and digitally signed, the data-collection form is issued, the tasks for that stage are created with an owner and a due date, and the people involved hear about it in the team chat.

The templates for those emails and tasks are configured by the office, not written in code. Staff pick a status, and the system knows what an Effizienzhaus project needs at that point that a single-measure project does not. Proposals that go unsigned expire and archive themselves. A completed project can spawn a follow-up that inherits its data and files.

The decision that mattered: we did not build a workflow tool with its own vocabulary. We took the status numbers the engineers already used and made the software answer to them.

02Every file lands where the next person will look for it.

The office keeps its files on its own server, and that was not going to change. So the system files everything where the office already looks for it. A folder tree is created for every new project in the shape that project type needs, and as the project moves, folders move with it. More than twenty automations do nothing but this.

Clients upload their own paperwork into a dedicated folder, and clients name files the way clients do. A small model reads each upload, works out the supplier and the date, and files it into a folder per supplier under a proper name. It only acts when it is sure. Anything ambiguous stays where it was, for a person.

Signed documents from the pipeline, the power of attorney, the legal notices, the confirmations, are filed into the contract folder automatically, named by date, client and document, without anyone dragging anything.

03The screens are the office’s, not off the shelf.

The data lives in one database, 23 tables of it, that the office can open and correct itself. But default screens were never going to carry a 21-stage process. So we built the working views on top of it: screens that only this office will ever use.

A projects board across the three subsidy programmes, with a column per approval stage and drag to advance. An email template editor where each status has its letter, with placeholders that fill from the record. A task template manager that defines, per status, who does what, by when, and who is told.

Data gets in through 44 forms, some for staff and some for clients: creating and editing a client, capturing the building survey, accepting a proposal with a signature, choosing which legal notices apply. A form submission is an event the pipeline reacts to, not a row someone copies later.

04The books and the projects agree.

Hölzl keeps its books in the accounting package most German firms use, and that stays. A sync service we run keeps the books and the project records agreeing in both directions: customers, quotations, order confirmations, invoices, suppliers and payroll. Jobs run in dependency order, with reconciliation, conflict handling and an audit trail.

Invoice PDFs are attached to their project as vouchers, so revenue by programme, margin and pipeline forecast come straight from the data, drawn as one more view inside the system.

A sync that is right most of the time is worse than none, because nobody knows which part is wrong. Most of the engineering here went into the unglamorous cases: a client with a separate billing address, a record edited on both sides between runs, a municipality that is a company in one system and a person in the other.

The engineers do engineering.

The office runs its projects across three subsidy programmes on the system, with 64 in flight at the last count and well over a hundred completed through it. Letters, documents, tasks and notifications happen because a status changed, not because someone remembered.

The numbers describe the system, not the outcome, because the outcome is quieter than a number: an office of engineers whose day is spent on buildings, and an operations layer that has been added to more than 150 times without ever being taken down.

21

stages, each with its own letters, documents and tasks

90

automations in production

100+

projects completed through it

150+

features shipped since May 2025

The proposal analyser we built for the same office, which classifies contractor quotes line by line for subsidy eligibility, is told in full on the AI Workflows page.