Build a usable record of the existing house
Collect plans, alteration records, energy certificate, available service records, previous leak reports and utility information. Walk through roof/attic, external walls, basement, floors and installations with an appropriately qualified surveyor. Record location, observation, evidence needed and responsible specialist. A damp mark is an observation; its source and repair remain a question until investigated.
Ask what can be assessed without opening surfaces and what needs a separately agreed intrusive survey. A visual visit has limits. Keep a brief record of inaccessible areas rather than assuming them sound. A purchase survey, structural assessment, energy advice and installation inspection have different purposes and are not automatically included in one low-priced visit.
Investigate before disturbing old layers
The BAuA information on asbestos warns that older buildings and later refurbishment layers can contain affected products. Establish construction and alteration dates, proposed disturbance and competent investigation. Do not identify safety by colour or photographs, and do not make sanding or demolition a preliminary DIY task.
Ask specialists to define isolation, access, investigation and disposal requirements for the actual findings. Keep hazardous-material removal outside an ordinary debris allowance unless it has been assessed and priced. Also check unstable elements, water ingress and unsafe installations before allowing occupants or unrelated trades to rely on the space.
Check current obligations instead of copying an old checklist
The current federal law is the Gebäudemodernisierungsgesetz (GModG); the July 2026 reform changed the former GEG and its numbering. For example, the qualified top-floor ceiling/roof provision is now section 35. Its two-year ownership-transfer rule has specific conditions and a first-transfer history; it is not a fresh blanket deadline to renovate every purchased house.
Have a competent adviser identify the current obligation, evidence, exception if relevant and due date for this property. Check actual public procedures with the local authority; in Berlin use the responsible district. Heritage status, structural proposals and changes of use need their own assessment. An energy certificate does not establish that all permissions or installation checks are complete.
Divide decisions into urgent, occupation and later work
| Finding | Next decision | Budget treatment |
|---|---|---|
| Roof leak | Find source, stabilise and define permanent repair | Survey and protection first; replace allowance with scoped repair |
| Uncertain electrical condition | Competent assessment and specified remedial work | Separate assessment from installation quote |
| Poor thermal performance | Coordinated energy strategy and interfaces | Measure packages; do not copy a national €/m² figure |
| Damp basement | Investigate water source and intended use | Do not book cosmetic painting as a proven cure |
| Future extra room | Check safe separation and dependencies | Defer only work that can be genuinely separated |
Use an individual renovation roadmap to coordinate energy improvements where appropriate. It is a planning tool, not proof of funding approval or a detailed execution design for every trade. Weather protection and safety may be urgent even when a long-term envelope and heating strategy is still being developed.
Prepare an explicit funding model
| Item | Amount |
|---|---|
| Initial investigations, separate from later design | 2 975 |
| Defined works: EUR 91,000 net plus 19% | 108 290 |
| Subsequent design and specified checks | 5 950 |
| Access, external transport and ordinary disposal | 3 570 |
| Temporary living and storage | 4 800 |
| Identified unresolved work | 5 950 |
| Chosen reserve: 10% of gross works | 10 829 |
| Total model funding | 142 364 |
If the named EUR 5,950 unresolved task becomes an accepted EUR 4,760 gross job, replace the allowance: funding becomes EUR 141,174 with reserve unchanged. Do not add the new contract to the old allowance. The EUR 10,829 reserve cannot make an unassessed structural or hazardous-material problem a priced certainty.
Decide whether moving in is realistic
- Identify safety and weather-protection requirements with specialists.
- Confirm a usable bathroom, safe services, access and required separation.
- Coordinate concealed work before final finishes.
- Secure applicable approvals and a programme for dependent trades.
- Check full cash needs and temporary housing alternatives.
- Review remaining defects and documents before occupation.
Do not equate “we can afford the first invoice” with “the house is ready to live in”. Keep investigations, accepted packages, future options and recorded payments distinct in Reno Pro. A useful decision is to proceed with a defined first phase while leaving an unassessed major intervention unresolved, rather than promising the entire house on an unsupported number.
Sources, date and scope
- Bundesanstalt für Arbeitsschutz und Arbeitsmedizin — Informationsportal Asbest — FAQ
- Bundesministerium der Justiz / Bundesamt für Justiz — Gebäudemodernisierungsgesetz — geltende Fassung
- Bundesministerium der Justiz / Bundesamt für Justiz — GModG § 35 — Nachrüstung
- Land Berlin — Senatsverwaltung — Informationsportal der Obersten Bauaufsicht
- Verbraucherzentrale — Individueller Sanierungsfahrplan
Checked on 19 October 2026. Local examples concern Berlin unless stated otherwise. Check state law, heritage protection, community rules and actual work for the specific project. Teaching figures are invented euro amounts, not market prices or offers. The article projects are independent. Tax and funding calculations apply only under the stated assumptions; competent professionals resolve project-specific technical and legal questions.