Short answer
What you need to know first.
The solar offensive is a planning and timing topic for owners in Basel-Stadt: the government wants to extend the existing self-generation obligation for new buildings to suitable existing buildings, with exceptions and a transition period. For real projects, the headline is not decisive; roof area, protection status, permit path, incentives, IWB process and self-consumption model must be checked.
Important
This page provides general guidance based on publicly available information. The solar offensive was submitted by the government to the Grand Council as a proposal; detailed rules, entry into force and transition provisions must always be checked against the current cantonal status for real projects. It does not replace legal, tax, subsidy or construction advice or a property-specific assessment by the municipality, authorities, IWB or planners.
Decision points
What determines the right path.
The official solar offensive proposal is based on suitable roof areas and names a suitable roof area above 100 m² as a central threshold. Smaller roofs, technically unsuitable sub-areas, areas already used differently and certain protected buildings may be treated differently. Planning therefore starts with roof and property assessment, not with a blanket obligation statement.
Permit procedure and usage obligation are two different questions. Standard systems in Basel-Stadt may be subject to notification, while systems in protected zones, on cultural monuments or with insufficient adaptation may require a building permit. Separating these issues prevents wrong schedules.
Basel-Stadt is a dense urban canton. Flat roofs, roof terraces, green roofs, technical structures, fire and maintenance access and shading from neighbouring buildings significantly affect usable PV area. The solar cadastre is a starting point, not a substitute for a roof survey.
The IWB process belongs early in the workflow. Connecting an energy generation system requires technical documents, acceptance and clean handling of compensation and guarantees of origin. Clarifying grid connection, metering and incentives only after installation risks follow-up questions.
Self-consumption, ZEV, vZEV or local electricity models can be more economically relevant in Basel-Stadt than pure feed-in. IWB publishes feed-in tariffs and offers local solar electricity models; the suitable variant depends on consumers, building structure and metering concept.
Sequence
How the project stays cleanly managed.
- 1
Clarify property statuscheck roof area, solar cadastre, existing roof use, technical structures, green roof, ownership structure, heritage status, inventory entries and protection zone. This shows whether a standard project is realistic or deeper pre-clarification is needed.
- 2
Determine the procedurefor sufficiently adapted systems on many roofs, notification is the leaner path. In protected zones, on cultural monuments, on facades in preservation zones or with insufficient adaptation, a building permit must be planned. The responsible authority decides for the specific property.
- 3
Develop the technical conceptplan module area, mounting structure, ballast, roof membrane protection, maintenance paths, inverter location, cable routing and fire-protection interfaces so roof, electrical work and permitting use the same documents.
- 4
Integrate IWB and incentives into the project workflowconnection request, technical data, acceptance protocol, feed-in tariff, guarantees of origin and Pronovo documents should be prepared consistently. Cantonal incentive or solar-offensive rules must be checked against the current status.
- 5
Decide only after comparing variantson densely used Basel roofs, full coverage, partial coverage, east-west layout, facade option, battery storage, ZEV or pure self-consumption can produce different results. The quote should reflect this project logic instead of just selling kWp.
Checklist
Questions to settle before the quote.
- Check roof area above 100 m², protection status and existing use early
- Separate notification procedure, permit requirement and heritage review cleanly
- Plan IWB grid connection, feed-in tariff and self-consumption in one workflow
- Do not confuse incentives and possible obligation timing with a quote
FAQ
Common questions on this topic.
Sources
Official sources & references.
The responsible authorities are decisive. Always verify binding details – amounts, deadlines and conditions – for your specific property against the current status of the respective authority.