As it is well known, the EPBD [6] imposes the establishment of minimum requirements for thermal performance of buildings, and, for new buildings with a total useful floor area over 1 000 m2, Member States shall ensure that the technical, environmental and economic feasibility of alternative systems such as decentralised energy supply systems based on renewable energy is considered and is taken into account before construction starts (Art. 5).

The new Portuguese thermal performance building regulations related with the EU Directive 2002/91/CE [6], were published in the Official Portuguese Journal (DR — Diario da Repbblica, http://dre. pt/), on the 4th of April 2006. The official documents are:

• Building Certification National System on Energy and Interior Air Quality (SCE [8]), which transposes, together with both RSECE [9] and RCCTE [7], to the Portuguese legislation the EPBD [6], related with energy performance of buildings, and which defines the requirements of the qualified experts that can manage the certification process;

• Air Conditioning Energy Systems Regulation (RSECE [9]), which defines hygienic and thermal comfort conditions, and imposes rules for the air conditioning systems efficiency, for its maintenance and for keeping the quality of interior air, to achieve a better global energy efficiency of buildings. It imposes as mandatory priority consideration in both new buildings and major renovations, with the exception of fault of technical availability demonstrated by the designer under a mandatory methodology, the usage of flat solar collector systems for hot sanitary water production (Clause 2.a) of RSECE, Article 32);

• The referred Thermal Performance Building Regulation (RCCTE) [7], which improves the already existing regulation, almost duplicating the thermal performance request in the new and renovated buildings and imposing the usage of solar thermal collectors for hot water production if there is favourable conditions for exposure (if the roof or cover runs between SE and SW without significant obstructions) in a base of 1m2 per person (the total can be reduced to 50% if space is necessary for other important usages of the building).

Other important requirements of the Portuguese STO defined within RCCTE [7] are the following:

— For performance calculation of such systems, the product certification according to the European Standards is needed.

— This performance calculation is done using a programme developed by INETI, the SolTerm code.

— The installers of these systems must also be certified installers.

— The solar system must be guaranteed by a six year maintenance contract, covering the whole solar thermal system..

• The implementation calendar and taxes of Building Certification National System on Energy and Interior Air Quality [10, 11], is being managed and supervised by the National Energy Agency, ADENE : it began in July 2007 for some type of new buildings, in July 2008 for all new buildings and in January 2009 is extended to existing buildings in the way of a commercial transaction.

Fiscal incentives are available at the moment in Portugal:

a) The annual income taxation of individual contributors can be reduced by 30% of the acquisition value of new equipments for renewable energy production, with a limit of €777 [13];

b) The annual income taxation of collective contributors can be reduced by the value invested in renewable energy equipment at the annual rate of 25% of the overall purchase [14].

c) The VAT incident on renewable energy equipment has the intermediate value of 12 % [15].

An incentive scheme is also available:

a) On SME Qualification and Internationalization Regulation [16], which permits to be eligible the cost of acquisition of the equipment used for both energy efficiency and renewable energy production, and their costs with technical assistance, audits and tests. The energy efficiency and renewable energy production is one of 13 components. The maximum incentive for an individual project (with all their components) is € 250,000.

b) In the Azores Islands there is a Regional Incentive Programme. It is a direct incentive to the acquisition of renewable energy systems up to 25% of the system cost and a maximum of 1000 €. For companies, the maximum value of the incentive is 250000€, also up to 25% of system cost

[17] .

c) Also in Madeira Island there was a Regional Incentive Programme [18] for solar thermal systems for hot water production for dwellings, between years 2002 and 2006. This has now stopped. The collector area installed with this incentive was 3200 m2. It was an incentive up to 1000€ per apartment or 10000€ per building of apartments and up to 70% of the total investment. The incentive was calculated as a function of the energy delivered by the system.