In short. A self-builder — autopromotor in Spanish — promotes the building of their own home instead of buying it from someone else. You keep the developer’s margin and take on the developer’s role: the one in articles 9, 17 and 19 of Law 38/1999 on Building Regulation (Ley de Ordenación de la Edificación, LOE).
The process is ten steps and about two years. They are all below, with what you need at each one and what changes in the Comunidad de Madrid — the region, a different administration from the Ayuntamiento de Madrid, the city council. On several steps it is not what most pages say.
The ten steps
Finding the right plot
Before the price, five things: location, vehicle and pedestrian access, services —water, drainage, electricity and telecoms up to the boundary—, topography and, above all, planning rules: what can really be built there. They are municipal rules, so neighbouring plots can allow very different houses. See what you can build on your plot.
You also have to check charges, encumbrances and burdens, which are recorded at the Registro de la Propiedad (the Land Registry, a different body from the Catastro, the registry kept for tax purposes). It is the most expensive mistake in a self-build, because by the time you find out you have already signed. If the ground has steep slopes, fill or an odd history, look at the subsoil before buying, with a ground investigation report.
Buying the plot
Financing a plot does not work like financing a house: you need more savings. Three routes. With a bank, bearing in mind that many lenders refuse to finance land and those that accept impose hard terms. With your own money. Or buying with the design and permit already under way — the best option, because the plot is then valued together with the house.
This is where the self-build mortgage comes in: it is not handed over in one go but in stages, against interim certificates of work built.
Appointing the architect
Talk to several studios and look at their finished buildings, not just their renders. Once chosen: a contract with the services itemised, payment terms, a topographic survey and a ground investigation report.
Spanish law splits the site team in two, and both are compulsory: the arquitecto (architect), who directs the works (article 12 of the LOE), and the arquitecto técnico or aparejador — closest to a quantity surveyor — who directs their physical execution (article 13). You cannot hire only one; Fran Cortés holds both.
Developing the design
The proyecto básico (outline design) sets the general characteristics and is what you apply for the permit with, but it is not enough to build from. The proyecto de ejecución (detailed design) develops it fully, defines every material and system, and is the one stamped and built from.
That stamp is the visado colegial: the architects’ professional body, the colegio, certifies that whoever signed is registered, insured and entitled to sign. With the design goes the health and safety study: without it there is no visado and no permit.
The administrative side
ICIO, the municipal tax on construction, installations and works, is charged on the material execution cost. Each town hall sets its rate and it cannot exceed 4 % (article 102 of the consolidated text of the Local Finance Act). On top goes the permit fee, a separate charge that also varies by municipality. It is the ayuntamiento, not the State, that sets the rate and the fee and decides how long the permit takes, which is why the same house costs a different amount in two neighbouring towns. See the guide to ICIO and the building permit tax.
VAT comes at two rates: 10 % on the building work of a dwelling contracted directly with the builder, and 21 % on professional services and supplies of goods. Municipal taxes carry no VAT. The whole split, with the rates of your own town hall, is in the cost calculator.
Appointing the builder
A good part of the outcome is decided here. Give the builders all the information in the design, get your technical team in the room with them, and settle a fixed-price contract. Agree in writing that any extraordinary change is priced at project rates.
Check that the contractor and subcontractors are entered in the Registro de Empresas Acreditadas (the register of accredited construction companies): compulsory information on the notice of opening of the site.
Starting on site
By the day the acta de replanteo (the setting-out record) is signed, everything has to be settled: permit granted, detailed design stamped, health and safety plan approved by the coordinator, notice of opening of the site filed by the contractor, libro de órdenes (order book) endorsed by the colegio, and libro de incidencias (incident book).
The aviso previo (prior notice) that still turns up in many guides has been repealed since 2010. Its content goes today into the notice of opening of the site.
During the works
Visit the site, but do not take over from your technical team. Any change goes first to the dirección facultativa and is recorded in writing in a variation record, priced, and signed by all parties.
Payments go against a certificación de obra (interim certificate): the builder invoices, the dirección facultativa checks what has been built and issues the certificate. With a mortgage, that certificate is what releases the money.
Completion
Three documents. The certificado final de obra (the completion certificate), signed by architect and aparejador and stamped by the colegio. The libro del edificio (the building manual). And the acta de recepción (the handover record), the formal handover, which starts the ten-year, three-year and one-year warranty periods.
You can accept the works with reservations. If you do, the warranty periods run from the day the items are put right, not from the signature.
Legalising the house
Final settlement of ICIO on the real cost. First occupancy, which in Madrid is no longer a licence but a declaración responsable (a self-certified declaration). Declaración de obra nueva, the notarial deed that makes the house exist on paper, and registration at the Registro de la Propiedad. And entry in the Catastro.
With that the house legally exists and the permanent supplies can be contracted. Both deeds pass through a Spanish notario, a public official who answers for the legality of what he authorises. He is not a solicitor and does not act for you, so you still want your own lawyer.
Three things almost every guide gets wrong
The aviso previo
Still listed as a step on dozens of pages. It has been repealed since 24 March 2010 by Royal Decree 337/2010. Its content was folded into the notice of opening of the site.
The cédula de habitabilidad
In the Comunidad de Madrid it has not existed since 2018: Decree 111/2018 abolished it. Nobody issues it. If you are asked for one, someone is applying another region’s rules.
The warranty periods
They do not start with the completion certificate. They start with the acta de recepción (article 6.5 of the LOE). The certificate only fixes the date the works finished.
What you need to be clear about before you start
- What can be built on the plot, with the planning rules in hand
- What all of it costs, not just the building work
- How much you have and where it comes from
- Whether the land carries charges, easements or burdens
- Who directs the works and who directs the execution
- What contingency reserve you will keep
- How the bank will release the money, if there is a mortgage
- How long the permit takes at your own town hall
The number that causes the most grief. Most of the shocks in a self-build come not from the building work but from starting with the wrong number in your head. Someone multiplies square metres by a price read somewhere and finds out six months later that the town hall, the works outside the plot, the VAT and the contingency were missing. The cost calculator adds up every item with your municipality’s rates; the figures behind it are in how much it costs to build a house in Spain.
Frequently asked questions
What exactly is a self-builder?
The person who promotes the building of their own home instead of buying it from a developer. In law you take on the developer’s duties in article 9 of Law 38/1999 on Building Regulation (Ley de Ordenación de la Edificación, LOE): commissioning the design, appointing the technical team, obtaining the permits and signing the acta de recepción.
How much do you save by building it yourself?
You save the developer’s margin. It is not a fixed or guaranteed figure: it depends on the land, on the builder and on the design being properly closed before work starts. What is certain is that you take on the risk and the management the developer used to take on.
Do I need ten-year structural insurance if I build for myself?
No. The second additional provision of the LOE exempts an individual self-builder of a single detached home for their own use. With a catch: if you sell within ten years you must take the policy out for the time remaining, unless the buyer expressly releases you and you can show you have lived in the house. Without that the sale deed is neither authorised nor registered.
How long does a self-build take from start to finish?
It depends above all on the town hall. From commissioning the design to the keys usually runs to two years: six to nine months of design and permit, twelve to sixteen of building work. The permit is the least predictable variable, because it is the ayuntamiento (town hall) that grants it and each one sets its own deadlines.
Can I start work as soon as I have the proyecto básico?
No. The proyecto básico is what you apply for the permit with, but it is not enough to build from. You need the proyecto de ejecución, stamped by the colegio, and the permit granted. Starting before that is building with no authorisation. See building permit requirements in Madrid.
Is the aparejador compulsory?
Yes. The LOE requires a dirección facultativa, and on a house the direction of the physical execution belongs to the arquitecto técnico (article 13). The completion certificate is signed by both, architect and aparejador.
What happens if I run out of money halfway through?
That is the real risk of a self-build, and why the contingency reserve is not optional. With a self-build mortgage the bank releases money against interim certificates: a site that has stopped generating certificates stops receiving money.
Can I engage the trades directly and do without a main contractor?
You can, and Royal Decree 1627/1997 (article 2.3) has an exception that stops you becoming the contractor when you engage self-employed trades for your own home. But you are still the developer: the health and safety study and the coordinator remain compulsory. And if you bring in self-employed workers, you become an employer for all purposes.
Is the Comunidad de Madrid the same thing as the Ayuntamiento de Madrid?
No, and the difference matters at almost every step. The Comunidad de Madrid is the region and legislates on land and habitability; the Ayuntamiento de Madrid is the council of one of its municipalities. Region-wide rules such as Decree 111/2018 come from the Comunidad; the permit, the ICIO, the fee and the timescale come from your own town hall.
We take you through the ten steps
As dirección facultativa we sign the design, direct the works, issue the certificates the bank releases money against and sign off completion. We also handle the ayuntamiento, where most of the time gets lost.
Tell us where the plot is and what stage you are at.