What legal requirements exist for electrical systems, plumbing and heating during renovations?

Technology in focus: safety, hygiene and energy

Electrical systems: Safety allows no compromises.

Electricity is invisible and odorless, but it can be deadly. Therefore, legal requirements for electrical renovations are particularly strict. The Low-Voltage Installation Ordinance (NIV) is the relevant regulation.

The Safety Certificate (SiNa): One of the most important legal requirements for renovations concerns the safety certificate. A current SiNa (not older than 5 years, otherwise 20 years) is required whenever a property changes hands (purchase) or when significant changes are made to the electrical installation. If you are renovating and installing new wiring or expanding the fuse box, you will need a new inspection by an independent inspector. Legal regulations for renovations stipulate that installation and inspection must be strictly separated.

No "do-it-yourself" here: Many DIY enthusiasts feel confident enough to hang a lamp. However, legal regulations for renovations place strict limits on self-performed work. In their own homes, laypeople are only permitted to carry out simple tasks (e.g., installing cover plates, replacing individual sockets) – and only on circuits protected by a residual current device (RCD). Anything beyond this is subject to the legal regulations for renovations , which require qualified professionals. Anyone who illegally rewires their own electrical system risks losing their insurance coverage in the event of a fire.

Retrofitting requirements: Are you planning new electrical outlets in your bathroom or kitchen? Legal regulations for renovations now mandate residual current devices (RCDs) for almost all circuits. Old screw-in fuses are often no longer permitted during comprehensive renovations and must be replaced to comply with these legal requirements .

Sanitary facilities: Water hygiene and noise protection

Water is our most important resource. Therefore, legal requirements for renovations in sanitary facilities primarily focus on hygiene and health.

Materials and corrosion: Until the 1980s, galvanized iron pipes were commonly used. These corrode over time. When renovating a bathroom, legal regulations often apply , making mixed installations (old iron, new copper/stainless steel) problematic, as this accelerates rusting. The regulations (W3 guidelines of the SVGW) precisely define which materials may be combined. Often, these legal requirements technically necessitate the complete replacement of the pipes up to the riser.

Noise control (SIA 181): Sound insulation is an often underestimated aspect of legal renovation requirements . The SIA 181 standard regulates how loud your neighbors are allowed to be when you shower or flush the toilet. If you're renovating the bathroom in a condominium, you must meticulously comply with the legal noise control regulations . This means that pipes must be insulated and decoupled. A bathtub that sits directly against the wall and transmits sound violates these regulations and can lead to costly lawsuits demanding its removal.

Legionella protection: When replacing hot water systems (boilers), legal regulations for renovations stipulate that the water must be regularly heated to 60 degrees Celsius to kill Legionella bacteria. "Dead ends" (sections of pipe where water is stagnant) must be removed to comply with these hygiene regulations .

Heating: The driver of the energy transition

Nowhere are the legal requirements for renovations more dynamic than in the area of heating. The cantonal model regulations in the energy sector ( MuKEn ) set the pace.

Replacing fossil fuel heating systems: Do you want to replace your old oil or gas heating system? This is where the strictest legal requirements for renovations come into play. In many cantons, a direct replacement of a fossil fuel heating system is no longer permitted without implementing efficiency improvements. These legal requirements often stipulate that at least 10% (in some cantons more) of the energy demand must be met by renewable energy sources or saved through insulation. This means that anyone wanting a new gas heating system often has to simultaneously replace windows or install solar panels to comply with these legal requirements .

Heat pumps and noise: Switching to a heat pump is popular. However, legal requirements for renovations , especially regarding noise protection, also come into play. The outdoor unit must not disturb the neighbors. You must provide mathematical proof (noise protection certificate) that the legal requirements of the noise protection ordinance are met. Without this proof, a building permit will not be granted.

Insulation regulations: If you also work on the facade as part of your heating system renovation, energy efficiency regulations for renovations apply . The U-value (heat transfer coefficient) must meet certain standards. A simple " brush-on" renovation of the facade won't trigger these requirements, but as soon as you insulate, you have to do it properly according to the legal regulations for renovations .

Consider regional differences

Switzerland is a federal state. This means that legal requirements for renovations can vary from canton to canton. While electrical regulations (NIV) apply nationwide, energy laws ( MuKEn ) are a matter for the cantons. What applies in Zurich may not be the same in Aargau. Legal requirements for renovations can also be influenced at the municipal level by zoning plans (e.g., a ban on air-source heat pumps in densely populated village centers). It is therefore essential to contact the local building authority before starting construction to inquire about the specific legal requirements for renovations .

Conclusion

The question of regulations is crucial for your budget and timeline. Legal requirements for renovations ensure that your house is safe, quiet, and energy-efficient. Never ignore legal requirements for renovations in the areas of electrical systems (proof of safety!) and heating ( MuKEn ). Violations can cost you your insurance coverage and reduce the property's value upon later sale, as illegal construction constitutes a defect.

view legal renovation requirements as an obstacle, but rather as a quality standard. A house that meets current standards retains its value better. Consult professionals who are familiar with the current legal requirements for renovations and will take responsibility for their correct implementation.

If you need support in checking the regulations for your project or are looking for a feasibility analysis, Loft offers professional advice and planning tools for this purpose.

Glossary

• Legal requirements for renovations: The entirety of all legal regulations (federal, cantonal, municipal) that must be complied with during renovations.
• SiNa (Safety Certificate): A mandatory document according to legal requirements for renovations , confirming the safety of electrical installations.
• MuKEn : Model regulations of the cantons in the energy sector. They define the legal requirements for renovations to heating and insulation.
• NIV (Low-Voltage Installation Ordinance): Federal regulation that governs the legal requirements for renovations and work on electrical installations.
• SIA standard: Technical standards of the Swiss Society of Engineers and Architects (e.g. noise protection), which are often considered recognized rules of building science and thus as indirect legal requirements for renovations .