Renovating in Delémont: A practical guide for property owners

Delémont, located at 418 meters altitude, has a climate characterized by significant heating requirements with approximately 2931 degree-days per year. The city records 62 frost days annually, requiring special attention to the thermal performance of building envelopes.

9 °C requires robust heating systems and efficient insulation to maintain optimal indoor comfort.

The Delémont building stock, home to 13,000 residents, benefits from architectural diversity that requires rigorous planning. Water management is also a technical point to note, with hardness ranging from 24 to 27 °fH, an essential datum for the maintenance of sanitary facilities and boilers.

The revised energy master plan highlights the importance of a transition to sustainable systems by combining efficiency, sobriety, and increased use of renewable energies by 2050.

To improve the energy efficiency of your property in Delémont, priority is given to the building envelope. Facade insulation and the replacement of old windows are the pillars of this strategy.

These interventions allow for a significant reduction in energy consumption needed to compensate for the 2931 local degree-days.

Additionally, the use of renewable energies is encouraged. With an average global irradiation of 1270 kWh/m²/year, photovoltaics represent a major opportunity for south-facing roofs, with an estimated yield of 1118 kWh/kWp/year. The shift towards heat pumps, supported by cantonal subsidies, is part of the 2050 roadmap.

It is advisable to conduct an energy audit before any intervention to target the most critical heat loss points in your home.

Heating in Delémont is evolving with the development of the 'Cras-des-Fourches' district network, operated by the Services industriels de Delémont, whose municipal takeover was announced for April 2025. This network uses wood and gas. However, connection is not universal; it depends on your precise geographic location.

Regarding the replacement of fossil-fuel boilers, the Energy Ordinance (OEn) of the Canton of Jura is evolving. As of April 1, 2026, it will be possible to replace a gas boiler with a new one, provided that at least 20% of heating and domestic hot water needs are covered by biomethane or renewable gas.

This gas must come from installations located in the Canton of Jura and be certified by guarantees of origin. This rule demonstrates the cantonal commitment to gradually decarbonize the existing thermal stock.

Any significant transformation of a building in Delémont requires a building permit application from the municipal authorities.

This applies particularly to projects that change the exterior appearance, such as facade insulation, the installation of photovoltaic panels, or changing windows visible from public thoroughfares.

Respecting built heritage is a priority in Delémont. Before starting work, ensure your project complies with current regulations. If your property is listed or located in a protected area, specific constraints will apply. It is recommended to contact the local urban planning department very early in the planning phase.

They will be able to guide you on authorized materials and renovation techniques compatible with the historical aesthetic, thus ensuring your work adds value to your property while preserving the visual identity of the municipality.

Property owners in Delémont can benefit from various financial aids for their energy renovation work. The Canton of Jura, via the 'Building Program' website, offers subsidies for replacing fossil-fuel heating with heat pumps, facade insulation, window replacement, and solar thermal installations.

Additionally, the federal one-off remuneration supports photovoltaic projects, with amounts calculated based on installed power.

Regarding taxation, the Canton of Jura allows for interesting deductions. Expenses for energy efficiency are deductible as actual expenses. For maintenance, you can deduct a flat rate of 10% of gross yield (or 20% if the building is over 10 years old), or opt for actual expenses.

This structure helps optimize the overall cost of your work. It is essential to keep all your invoices and energy performance proof to validate these deductions with the tax authorities.

A successful renovation in Delémont relies on rigorous planning. Start by defining your priority needs, then contact qualified professionals. For energy work (heat pump, insulation, solar), prioritize specialized companies with the necessary certifications, as they can advise you on subsidy applications.

Request several comparative quotes, not only on price but also on the proposed technical solutions and completion times. Verify that the companies are accustomed to local specificities and cantonal Jura standards. Coordinating the different trades is crucial to avoid planning errors.

Do not hesitate to ask for local recommendations to choose trusted companies. A good craftsman will also know how to anticipate constraints related to water hardness or local climatic conditions when installing your equipment.

Finally, always formalize the warranty conditions and payment deadlines in writing before the work begins.