Existing Buildings: Understand the Practical Benefits and Legal Framework

Existing buildings include all constructions completed and licensed under previous legal regulations that continue to serve their original purpose after multiple legislative changes. This classification directly affects the regulatory framework and renovation obligations, protecting built heritage without imposing disproportionate costs on owners arising from new legal requirements.

"Existing buildings are protected and benefit from specific legal regimes that grant exemptions and prevent disproportionate burdens during maintenance or upgrading."

1980s building in Cascais

Benefits and Exemptions for Existing Buildings

Existing buildings enjoy practical advantages compared with new construction and urban planning rules. These benefits provide greater stability for owners and encourage rehabilitation efforts throughout Portugal.

• Exemption from new regulations: Buildings constructed under older regulations are not affected by newer legal frameworks, except in cases involving extensions or increased non-compliance with current standards.

• Simplified licensing: Municipal Councils cannot deny licences for reconstruction or alteration based on laws enacted after the building’s construction, provided the changes do not increase non-compliance or affect safety and health improvements.

• Rehabilitation incentives: Works intended to improve safety, sanitation, or energy efficiency are permitted even when full compliance with current technical standards is not achievable, preventing excessive costs for owners.

Applicable Regulations

Despite these benefits, existing buildings remain subject to various legal obligations to ensure safety and maintain quality of life in urban environments:

• Periodic maintenance: All buildings must undergo conservation works at least once every eight years, as well as any interventions necessary to maintain safety, health, and visual integrity.

• Municipal oversight: Councils may require corrective works to address structural or sanitary hazards, and may also order the partial or total demolition of buildings posing a public health risk.

• Environmental and safety requirements: Buildings must ensure structural stability, fire and hygiene safety, acoustic protection, and thermal insulation in accordance with the General Urban Buildings Regulation (RGEU).

Regulations Exemptions

Conversely, there are situations where existing buildings may be exempt from specific rules:

• Supervening regulations: Legal and technical standards created after the building’s original construction and licence are not enforceable, except for works that worsen non-compliance or increase volume, area, or height.

• Accessibility exceptions: Accessibility standards are not required when adaptations are unfeasible or economically disproportionate, especially in heritage or historically significant properties.

Interior Architecture Project for an apartment in a 1980s building in Cascais

Practical Example

Consider a building constructed in the 1980s, with its typology and room dimensions approved at the time. If the owner chooses to remodel the interior without altering façades, structure, or total area, the project remains governed by the regulations applicable at the date of construction. Only when adding area, height, or making major changes do current regulations apply.

Comparison Table

Aspect	Existing Building	New Urban Regulations (Post-Construction)	Licensing for Alteration	Key Obligations	Exemptions and Exceptions
Legal protection	Protected under prior law	Generally applicable	Cannot be denied if non-compliance not aggravated	Maintenance every 8 years / Safety works	Technical standards waived when adaptations are unfeasible
Oversight	Subject to municipal control	Updated regulations apply fully	Encourages rehabilitation	Improve habitability and efficiency	Environmental or historical exceptions possible

Practical Advice for Property Owners

• Always identify the legislation in force at the time your property was built; it determines your entitlements and exemptions.

• When planning works, focus on improving safety and sanitation, as such interventions may benefit from flexible legal treatment.

• Consult an architect or qualified professional before carrying out alterations, rehabilitation, or reconstruction to ensure full legal and technical protection.

• Keep original project documents accessible; they are crucial for administrative and tax procedures.

• Follow municipal recommendations—councils may mandate urgent works if the building poses public or structural risks.

Important: Consulting qualified professionals is essential to ensure the safety, legal compliance, and long-term value of your property.

Key Takeaway

In Portugal, the preservation and enhancement of existing buildings are supported by favourable regulations that acknowledge the historical and functional value of the built environment. This framework promotes safe and responsible interventions aligned with social and economic realities. Engaging experienced professionals helps property owners navigate legislation effectively and make informed decisions for their assets.