Regional Law No. 12 of July 30, 2025, titled “Simplifications and Incentive Measures for Land Management”, was published in the Official Bulletin of the Lazio Region and entered into force on August 1, 2025. This long-awaited measure incorporates and expands the provisions of the “Decreto Salva Casa” (Law Decree 69/2024), introducing simplification and incentive measures that affect citizens, construction companies, and technical professionals.

Key Highlights of the Law

One of the most relevant changes concerns the redefinition of essential variations. The threshold beyond which a design modification is considered “essential” has been raised to 15% of the building volume or surface area. Previously, the limit was much stricter (around 2%), meaning that many minor discrepancies can now be regularized through compliance certification, making amnesties and building procedures simpler.

The law also introduces volumetric incentives. For residential buildings, extensions of up to 20% of the existing volume are allowed, with a maximum of 70 square meters—raised to 80 square meters if eco-building solutions are adopted (green roofs, rooftop gardens, sustainable techniques). For non-residential buildings, the extension can reach 150 square meters. In the case of demolition and reconstruction, the maximum increase is 40% of the original volume, with more limited thresholds for industrial properties.
Note: these figures are indicative and may be restricted in historic centers or protected areas; local municipal resolutions must always be checked.

Another innovation concerns the recovery of accessory or ancillary spaces. Surfaces previously excluded from building permits may now be recovered, up to 20% of the total volume and within a maximum of 100 square meters. Volumes strictly linked to agricultural activity remain excluded.

Important changes also affect the recovery of attics. The law allows the conversion of attics existing as of May 30, 2025, even if not connected to the underlying housing unit, provided they are intended as a primary residence. The measure also applies in historic centers, except for protected monuments. To ensure habitability, a minimum natural light-to-surface ratio of 1/16 is required for habitable rooms (excluding hallways, bathrooms, and storage rooms).
Technical note: national standards on minimum heights, installations, and energy efficiency must still be observed.

The law also regulates change of building use. Municipalities have until December 31, 2025, to approve their own regulations. If they fail to do so, from 2026 an automatic regime will apply: changes of use will be allowed up to 1,500 square meters in municipalities with fewer than 10,000 inhabitants, and up to 2,000 square meters in larger ones. Protected buildings and designated industrial or historic areas remain excluded.

Finally, the law introduces procedural simplifications: delegating some landscape authorizations to municipalities, streamlining processes for industrial plants and fuel distributors, and clarifying the compliance certification process, making it faster and more accessible.

Impact on Building Bonuses

The regional law does not directly introduce tax incentives but interacts with national benefits, which underwent significant changes in 2025.

The renovation bonus, reduced by the 2025 Budget Law, still provides deductions of up to 50% for primary residences, with lower rates (36%) for secondary homes, and further reductions planned for 2026 and 2027. Thanks to Lazio Regional Law 12/2025, interventions such as attic, basement, or accessory space conversions become easier to carry out and can therefore combine with this incentive.

Regarding the Ecobonus and Sismabonus, the regional law facilitates works that improve energy efficiency or reduce seismic risk. The adoption of eco-building techniques not only allows larger extensions but also increases the likelihood of accessing specific tax deductions. However, eligibility for bonuses remains subject to compliance with national tax rules and technical requirements (energy performance certificates, sworn statements, complete documentation).

The chapter on amnesties and building irregularities is equally important. With the Decreto Salva Casa and its regional implementation, many minor irregularities can now be regularized. This is crucial since urban and cadastral compliance is often a prerequisite for accessing building bonuses.

Limits and Constraints

Despite these openings, significant restrictions remain. In monumental buildings, historic centers, and protected landscapes, possibilities for extension or recovery are limited or excluded. National and municipal standards on habitability, structural safety, energy efficiency, and health requirements also remain in force: gaining volumetric rights is not enough—technical regulations must still be met.
Practical note: always consult a licensed professional and the local municipality before starting works.

Opportunities to Seize

Lazio Regional Law 12/2025 opens several opportunities for citizens and businesses:

• Recovery and enhancement of previously unused spaces (attics, basements, accessory surfaces);
• Volumetric extensions with incentives, especially when designed with eco-building solutions;
• Easier access to tax bonuses thanks to simpler urban planning compliance procedures;
• Clearer, uniform rules for change of use starting in 2026.

To make the most of these opportunities, it is essential to consult a licensed professional (architect, engineer, surveyor) who can assess local constraints, prepare the required documentation, and ensure full urban and tax compliance.

Lazio Regional Law 12/2025 represents a significant step toward more modern and sustainable land management. The simplifications make it easier to regularize building irregularities, promote the recovery of existing assets, and encourage interventions that can be combined with national tax bonuses. This is therefore a concrete opportunity to enhance real estate in Lazio, reduce bureaucracy, and improve building quality—provided that local constraints, technical standards, and fiscal rules are fully respected.

For detailed guidance on 2025 building bonuses and technical requirements, it is advisable to consult the Revenue Agency’s guidelines and always check municipal resolutions and restrictions before starting any project.