**4. Conclusion**

Tourism is the fastest growing economic sector in the world, with urban tourism among its fastest growing segments. It is crucial to understand the specificity of the city in relation to other tourist destinations. Urban tourism, undoubtedly, needs to preserve the resource that allows its existence according to the three pillars of sustainable development. Urban tourism can and should support sustainable urban development.

Urban tourism, on the one hand, offers the possibility of economic growth, while on the other hand, it exposes the vulnerability of the destination, which is the result of over-excitation and excessive and unplanned growth.

Sustainable urban planning and sustainable architecture are prerequisite to the sustainable urban tourism development.

Sustainable urban tourism and energy-efficient architecture are interdependent. All relevant stakeholders should take into account the environmental, social and economic impacts by highlighting the conscientious use of resources especially the non-renewable energy and water, waste minimisation and application of energy-efficient systems and optimisation of technology solution.

Green building certification programs (e.g. USGBC, LEED, BREEAM, etc.) promote costefficient and resource-saving framework as well as integration of sustainable development strategies during construction, use, maintenance, renewal and destruction of architecture in tourism. In addition, waste is generated and harmful substances are released into the atmosphere during those processes. These facts prompted the creation of standards and certification systems aimed to mitigate environmental impact in accordance to the principles of sustainable development.

The hospitality industry sector is energy intensively demanding. The use of renewable energy sources reduces operational costs, increases competitiveness and strengthens the green-building identity. In addition to reducing energy consumption from non-renewable sources, the application of the principles of energy-efficient architecture in tourism brings many significant benefits such as reduction of energy consumption, CO<sup>2</sup> emissions, improvement of guest comfort and reduction of the possibility for the occurrence of the 'sick building syndrome'.

Unfortunately, most hotels all around the world are energy in-efficient and have negative impact on the environment [37].

However, hotel companies' owners are reacting to positive ecological trends. Investing in sustainable architecture in tourism is often perceived as an obstacle to ambiguity about the ultimate goal. As Rincones notes [38], despite the usual assumption that initial investment is considerably higher for a sustainable, energy-efficient hotel, practice shows that if the holistic approach to a project that has integrated all the necessary strategies and principle into the planning stage, the total investment will be slightly increased, or in some examples (for the time being rare), zero-rise and even the reduction of the initial investment has been achieved.

Architecture in urban tourism, with its design and spatial solutions, is playing an important role for the identity and tourism development of a city. Although initially potentially higher, but certainly varying low-risk investments subjected to numerous external and internal factors will, in a relatively short period of time, result in faster revenue returns, lower costs, financial growth and positive cash flow.

Finally, and most importantly, consistent application of energy-efficient principles contributes significantly to the sustainability of urban tourism.
