Insights
Private swimming pools in Portugal: design, permits and safety
Summer brought the decision: the family wants a pool in the garden. Three quotes arrive from pool companies, all with optimistic schedules, and none mentions the municipality, the discharge of backwash water or the safety fence. The question that should open any conversation, «does this pool need a permit?», goes unasked. And the answer, contrary to what one hears on building sites, is not a simple «no».
An in-ground pool is serious construction: it moves dozens of cubic metres of earth, creates a permanent structure under considerable pressure and connects to the water and drainage networks. Treating it as a piece of garden equipment costs, at best, a legalisation process; at worst, a demolition or an accident.
Permit or no permit: what the RJUE says
The starting point is the RJUE, the legal regime for urban development and building. Its article 6-A exempts works of minor urban relevance from prior control and allows municipal regulations to classify other works as such. The construction of pools attached to a main building may be exempt from prior control where the municipal regulation classifies it as works of minor urban relevance; absent that classification, or where the regulation so determines, it may be subject to prior notification or to a licence, depending on the specific circumstances. The framework may also differ depending on whether the pool is autonomous or accessory to the main building. Several municipalities address the subject expressly in their regulations, with criteria of their own, as does the municipal building regulation of Grândola, which classifies as works of minor urban relevance the installation of prefabricated pools and jacuzzis, provided they involve no perimeter retaining works and no change to the natural relief or topography. Note how far that condition reaches: an in-ground pool, as a rule involving excavation and retaining works, tends to fall outside this exemption. Three practical consequences:
- the limits vary from council to council: the same pool can be exempt in one municipality and subject to a procedure in the neighbouring one;
- exemption from prior control does not waive compliance with the rules: the PDM, setbacks from plot boundaries, servitudes and restrictions still apply;
- without a provision in the municipal regulation, the general prior control regime applies, in the form resulting from the RJUE in force.
The framework for exempt works was revised with the Simplex reform and moves again with the 1 October 2026 amendments: the essentials are in our articles on works exempt from prior control and on DL 108/2026. Before digging, a written enquiry to the municipality or an analysis of the municipal regulation by a professional avoids surprises that are paid for in months.
Rustic land and sensitive zones: where the rules tighten
Outside the urban perimeter, the scene changes. On rustic land, building is exceptional and the pool depends on what the municipal plan admits for the plot and on being attached to an existing, legal building. In areas within the REN or RAN (national ecological and agricultural reserves), in protection zones of classified buildings and under other administrative servitudes, the framework is more restrictive and may require opinions from external entities or make the works unfeasible, depending on the case. The legal history of the house also counts: a pool «leaning» on an unlicensed annex inherits the annex's problem. In such cases, the serious route starts with the regularisation of the existing buildings.
The engineering behind the water: structure and waterproofing
A pool should be treated as an engineering work, with structural, hydraulic, drainage and safety designs. The tank of an in-ground pool works in both directions: full, it pushes against the ground; empty, it is the ground, and sometimes groundwater, that pushes against it. That is why the structural design, in reinforced or sprayed concrete, must consider earth pressures, the presence of a water table and the real risk of an empty pool floating in saturated ground. Waterproofing is the second pillar: reinforced liner, membranes or cementitious systems under ceramic finishes, with properly treated joints and edges, because a leak that is hard to locate becomes a chronic problem of water loss and decompression of the surrounding ground. On slopes, overall stability is added to the list: a poorly studied mid-slope pool can trigger earth movements that cost far more than the tank.
Hydraulics, filtration and network connections
The hydraulic circuit is the heart of daily operation: skimmers or an overflow channel, pump and filter sized to renew the volume in a few hours, well-distributed return inlets and a main drain. Three connections deserve design attention:
- the water supply, with backflow protection towards the public network;
- the discharge of filter backwash and emptying water, which cannot simply go to the street or the watercourse: the destination (drainage network, with authorisation, or an on-plot solution) is defined in the design, in line with the building services rules we cover in the article on water and drainage networks;
- the electrical installation, with equipotential bonding and residual current protection suited to an environment of water and bare feet.
Child safety: barriers, covers and alarms
Drowning is silent and fast, and family pools are the most frequent setting of accidents with small children. The European technical reference is the EN 16582 series for domestic swimming pools, which covers general safety requirements and the reduction of injury risk. EN standards are a technical reference and do not replace compliance with the RJUE, the municipal regulation and the applicable servitudes. The usual means of protection combine; they do not replace each other:
- physical barriers of adequate height with a self-closing gate between the house and the water;
- safety covers, rigid or bar type, able to bear the weight of a child;
- immersion or perimeter alarms, as a complement and never as the only protection;
- house rules: active adult supervision, floating toys out of the tank, restricted access.
In a holiday rental or rural tourism unit with a pool, these measures stop being merely good family practice and become part of the operator's responsibility towards guests.
Maintenance and running costs
The pool does not end at the acceptance of the works. Water treatment (chlorine, salt or other systems), the electricity consumed by pumping, water top-ups and winterisation weigh on the annual budget, and design choices influence them: a variable speed pump, a cover that reduces evaporation and a properly sized filter pay for themselves within a few years of operation. It is worth demanding, at the end of the works, the technical file with circuit diagrams, equipment datasheets and a maintenance plan.
The pool and VAT: outside the reduced rate
An expensive mistake discovered late: including the pool in the 6% VAT calculations. Decree-Law 97/2026, which created the reduced rate for housing construction and rehabilitation contracts, expressly excludes pools, saunas and similar equipment. In practice, even when the pool is built at the same time as the house, the part of the contract relating to the pool is taxed at the standard rate and must be itemised separately in the contract and invoicing, otherwise the benefit of the main contract is put at risk. The details of the regime are in our 6% VAT guide.
Frequent mistakes and risks
- digging without checking the municipal regulation, and discovering the missing procedure with the works done;
- assuming that exemption from prior control waives setbacks, the PDM and servitudes;
- building on rustic land or in a protected zone «because it is just a hole with water»;
- saving on waterproofing and paying for years of leaks and repairs that are hard to locate;
- discharging backwash water to the public road or the watercourse without authorisation;
- postponing the safety barrier «until the children are older».
Frequently asked questions
Do I need a permit to build a pool in Portugal?
It depends on the municipality. Article 6-A of the RJUE allows municipal regulations to classify certain pools associated with a main building as works of minor urban relevance, usually subject to conditions and limits set locally; within those limits, the works may be exempt from prior control, without prejudice to compliance with the other applicable rules. Outside them, or where the municipal regulation says nothing, the normal procedure applies. The criteria vary from municipality to municipality, and the framework differs depending on whether the pool is accessory to the main building or autonomous. The exemption never waives compliance with the PDM, setbacks and the other applicable rules.
What about rustic land or protected zones?
The rules tighten. On rustic land, building is limited and the pool depends on what the municipal plan admits for the plot; in REN or RAN areas, in protection zones of classified buildings and under other administrative servitudes, the framework is more restrictive and may require opinions from external entities or make the works unfeasible, depending on the case. Every case demands a prior check of the planning framework.
Which engineering specialties does a pool involve?
A reinforced or sprayed concrete structure sized for the pressures of ground and water, waterproofing compatible with the finish, a hydraulic circuit with filtration and pumping, water supply and an authorised discharge of backwash water, and an electrical installation with protection suited to wet environments. On plots with a high water table, the design must prevent the structure from floating.
Which child safety standards exist for domestic pools?
The European EN 16582 series sets safety requirements for domestic swimming pools, including the reduction of injury and drowning risk; physical barriers, rigid covers and immersion alarms are the usual means of protection. No equipment replaces adult supervision, but the combination of barrier and cover cuts the risk for small children drastically.
Does pool construction benefit from the 6% VAT rate?
No. Decree-Law 97/2026, which created the reduced VAT rate for housing construction and rehabilitation contracts, expressly excludes pools, saunas and similar equipment from the scope of that reduced rate. These works are taxed at the standard rate, even when integrated into a housing contract benefiting from the 6%, and must be itemised separately in the contract and invoicing.
Closing notes
A well-built pool starts far from the water: in the municipal regulation, in the study of the ground, in the structural and hydraulic design, in the barrier that protects the children and in the contract that separates the house's VAT from the tank's VAT. Done in that order, the works tend to run with fewer delays; done backwards, they drag on through legalisations and repairs. If you are thinking of building or legalising a pool, talk to CertiAmb: we check the framework in your municipality, develop the architectural design and the engineering specialties, and follow the works all the way to the first dive.
This article is provided for information purposes only and does not constitute legal, tax or technical advice. Each situation should be assessed individually by a qualified professional.