Doméstica Sede’s guide for buyers of complete buildings with heritage value

Purchasing an entire historic building—whether for full rehabilitation, residential conversion, rental investment, or long-term patrimonial preservation—requires a much deeper evaluation than buying a single apartment. The operation demands structural responsibility, financial solvency, and a clear strategic vision.

At Doméstica Sede, we work with institutional buyers, private investors, and families seeking to acquire full historical properties, and we know that success depends on a precise and realistic due diligence process.

Below is an essential guide to rigorously assessing the technical, regulatory, and economic condition of a historic building before acquiring it.

1. Structural Diagnosis: the foundation of every decision

In a full building, the structure is the factor most likely to alter the investment budget. It is essential to analyse:

  • Condition of load-bearing walls, pillars, and arches
  • Timber, iron, or mixed floor slabs
  • Deflections, deformations, and additional loads
  • Pathologies accumulated through age or previous interventions

A professional structural report can completely redefine the reasonable purchase price.

2. Damp and Roof Issues: the silent and most costly risk

In historic buildings, water-related pathologies tend to be widespread:

  • Tiled roofs with infiltration points
  • Deteriorated downpipes with long-standing leaks
  • Rising damp in ground floors and basements
  • Condensation in poorly ventilated courtyards

Before buying, it is crucial to calculate the true cost of full waterproofing or even partial roof reconstruction.

3. Previous refurbishments: quality, legality, and coherence

Many buildings have undergone interventions in past decades that now present problems:

  • Improvised structural reinforcements
  • Random or chaotic partition layouts
  • Concealed installations without documentation
  • Alterations affecting protected architectural elements

Understanding the building’s construction history is essential to avoid unwanted structural legacies.

4. General installations: the major hidden challenge

Acquiring an entire building means taking responsibility for:

  • Old water and drainage risers
  • Obsolete communal electrical networks
  • Staircases without fire-protection measures
  • Lack of detection and evacuation systems
  • Absent or inadequate climate-control solutions

Updating all installations to current regulations can represent a significant share of the total investment.

5. Heritage protection and regulation: the factor that shapes the whole project

Before purchasing, it is essential to understand what is allowed and what is not:

  • Level of protection (national, municipal, Grade 1, Grade 2, etc.)
  • Mandatory preservation of catalogued elements
  • Restrictions on façades, roofs, structural walls, and staircases
  • Requirements for major-works permits and technical projects
  • Limitations on horizontal division or change of use

A highly protected building is not a problem—but it does require a clear strategy and a specialised team.

6. Consolidation costs and return on investment

For a buyer of full buildings, the key question is:
How much will consolidation, rehabilitation, and value-enhancement truly cost?

This includes:

  • Structural consolidation
  • Restoration of singular elements
  • Complete new installations
  • Acoustic and thermal insulation required by law
  • Installation or refurbishment of lifts
  • Accessibility improvements
  • Façade and roof restoration

Accurate calculations prevent budget deviations and increase final profitability.

7. No existing owners’ association: advantages, risks, and opportunities

Purchasing a complete building eliminates the typical issues of a disorganised community, but also requires the buyer to assume:

  • All structural maintenance
  • All investment decisions
  • Full responsibility for works, permits, and safety

In return, it offers project freedom, faster appreciation, and total control over the asset.

8. Transformation potential: the factor that defines success

Beyond the technical aspects, it is vital to understand:

  • Real possibilities for redistribution
  • Ceiling heights and recoverable aesthetic value
  • Quality of patios, terraces, and natural light
  • Viability of creating premium apartments, boutique offices, or tourist accommodation (where permitted)
  • Historical identity capable of positioning the asset in a higher market segment

A carefully rehabilitated historic building can occupy a category of the market that is difficult to replicate.

Conclusion: buying a historic building requires vision and method

Acquiring a full heritage property is an extraordinary opportunity—but only if evaluated with a professional, technical, and strategic mindset. At Doméstica Sede, we help our clients to:

  • Identify real risks
  • Reveal hidden potential
  • Estimate costs with precision
  • Design a rehabilitation plan that is profitable and respectful

If you are considering the purchase of a historic building, we can accompany you from the initial inspection to the definition of the value-enhancement project.