At La Quinta Fachada, as an architecture studio based in Dénia, Alicante, we’ve spent years developing projects that transform single-family homes into multiple, functional, comfortable and fully legal living spaces. Today, we’ll walk you through everything you need to know about dividing a house into apartments in the Comunidad Valenciana — with no surprises and flawless results.

Why divide a house into apartments?

There are many valid reasons to take this step, and in most cases, they are entirely justified:

• To generate income through tourist or residential rentals

• To share the property among family members (parents, children, siblings…)

• To make better use of underutilised square metres in large or poorly distributed homes

• To adapt to new needs, such as independent spaces for young adults or elderly relatives

• To increase the property’s value for a future sale as independent units

When done correctly, dividing a house can lead to greater functionality, a stable income stream, and added property value.

Legal aspects: Can any house be divided in the Comunidad Valenciana?

Not all properties can be divided. Before beginning any renovation or project, it’s essential to carry out a legal and urban planning feasibility study. Key factors to consider include:

• Urban land classification (urban, rural, consolidated, etc.)

• Current municipal planning regulations (PGOU, local ordinances, etc.)

• Minimum floor area per dwelling as required by local legislation

• Independent occupancy certificates (cédulas de habitabilidad) for each unit

• Independent access, ventilation, natural light, and proper utility services

• Horizontal property division (mandatory if units are to be sold separately)

Each local council may have different requirements, so consulting a local architect is crucial to avoid costly mistakes.

Difference between physical division and horizontal division

Physical division: involves the construction work needed to physically separate the property (walls, doors, kitchens, bathrooms, utilities, etc.).

Horizontal division: is a legal and registry process through which two or more distinct dwellings are created within the same building, each with its own deed, ownership share, and individual community expenses.

Important: if you want to legally sell or rent the apartments as independent units, you must process the horizontal division through a notary and register it officially, while complying with all urban and technical requirements.

Architectural project: The foundation of it all

Once it’s confirmed that the division is legally possible, the next step is to draft a detailed architectural project, which should include:

• New spatial layout (partition walls, access points, circulation routes)

• Design of kitchens, bathrooms, and technical areas in each apartment

• Study of independent installations (electricity, water, climate control)

• Technical report, plans, measurements, and budget

• Documentation for applying for a major works licence and horizontal division

At La Quinta Fachada, we adapt every project to the specific features of the property, always seeking the right balance between aesthetics, functionality and efficiency.

Obtaining the licence: Essential permits to divide a house into apartments

To carry out the work with full legal guarantees, the following will be required:

• Apply for a major works licence from the relevant town hall

• Process authorisation for horizontal division

• Obtain new occupancy certificates for each unit

• Register the division at the Land Registry

• Adapt utility supplies (water, electricity, gas) for each dwelling

It may also be necessary to issue an energy performance certificate for each apartment.

Having a team of architects who can manage the entire urban planning process is key to ensuring a smooth and complication-free experience.

What design aspects should be considered?

The challenge of dividing a house into apartments isn’t just legal — it’s also technical and architectural. To ensure a successful outcome:

• Each unit must have sufficient natural light

• Rooms should be well-ventilated and properly proportioned

• Any shared areas must respect the privacy of each dwelling

• Durable, low-maintenance materials should be used

• Acoustic insulation solutions are highly recommended

In homes on the Costa Blanca, it’s also essential to adapt the design to the Mediterranean climate, prioritising energy efficiency and thermal comfort.

Financial and tax advantages

Legal division can open the door to valuable benefits:

• Possibility to sell the apartments separately, often increasing the total sale value

• Rental income, whether for short-term holiday lets or long-term tenants

• Easier inheritance processes or property transfers between family members

• In some cases, access to tax relief or grants for renovation and energy efficiency improvements

However, it’s crucial that everything is properly registered in order to take advantage of these benefits.

Common mistakes when dividing a property (and how to avoid them)

Some homeowners attempt to divide their house without professional advice, which can lead to serious issues:

• Unauthorised renovations without proper licences

• Urban planning violations resulting in heavy fines

• Refusal by the Land Registry to recognise the division

• Inability to rent due to lack of an occupancy certificate

• Shared utilities causing conflicts between units

That’s why we always stress: the support of a specialised architect is essential to ensure the project is viable, profitable and fully legal.

Dividing a house into apartments: Real success stories

At La Quinta Fachada, we’ve completed numerous projects in towns such as Dénia, Jávea, Altea, BenissaandMoraira, where large homes have been transformed into:

• Two or three fully independent apartments

• A holiday rental studio with a separate entrance

• A duplex plus an annexed apartment for relatives or passive income

• Renovated homes that gained both value and functionality

Each case is unique, but the outcome has always been the same: maximum space utilisation, well-executed design, and guaranteed legal compliance.

Invest with purpose, design with vision

Dividing a house into apartments is a strategic decision that can enhance your lifestyle, increase your property’s value, and bring peace of mind. But doing it right requires planning, professional guidance, and full legal compliance.

At La Quinta Fachada, we bring our expertise to those looking to transform their home into a functional, profitable space with added value.

If you’re thinking of taking this step, we invite you to contact us with no obligation. We’ll assess your case, evaluate the feasibility, and design a project that meets your goals.

Thinking about dividing your home into several apartments but don’t know where to start?

We’ll be happy to help. At La Quinta Fachada, we bring projects to life with technical precision, thoughtful design, and complete legal assurance.

La entrada Dividing a house into apartments: A complete guide to a legal, profitable and well-designed renovation se publicó primero en La Quinta Fachada: Arquitecto en Costa Blanca, Alicante y Valencia.