I’ve just returned from one of the most fulfilling building openings I have ever been to, that of the United Nations Ecobuilding in Podgorica, Montenegro. Even though this is technically no more advanced than any other low energy building I have designed, I believe that the potential for beneficial change that this building offers is greater than all the others put together.

The building, on the bank of the River Moraca, represents a ground-breaking new way of working for UN regional agencies as well as leading edge low energy building design. The building was the brainchild of Garret Tankosic-Kelly, formerly Resident Coordinator for the UN in Montenegro. The five UN agencies operating in Montenegro were working from independent locations in Podgorica. The creation of a new building was an opportunity to streamline operations as well as create synergies between the agencies.

The Austrian Government sponsored an architectural competition in 2005 to find a design for the building. I helped Daniel Fugenschuh, architect from Innsbruck develop the concept inspired by the sentiment ‘Delivering as One’ as described in the brief. All the UN agencies were to be placed on the same floor level and under a unifying roof form.

The Montenegro Government gifted land for the building in a prominent position on the edge of the Moraca River. The design responds to the location by recessing into the riverbank to create an iconic building without dominating the skyline. The work spaces project onto the riverbank like fingers, each housing two agencies with a fourth finger accommodating the café and terrace which can be used for informal meetings and social interaction.

Energy consumption has been substantially reduced compared to the norm for the region using simple methods such as providing plentiful natural light and natural ventilation in lieu of sealed construction and air conditioning. The river carries meltwater from the surrounding mountains and creates a natural pocket of cool air within its banks. This is utilised for passive cooling in conjunction with the massive, insulated concrete slab roof. Large rooflights, cut through the slab, allow daylight to penetrate into the offices below along with full height glazing on the western elevation overlooking the river.

The building is heated and cooled using a heat pump coupled to groundwater abstracted from a borewell on the site. Podgorica sits atop a vast underground catchment from the mountains, which surfaces in nearby Skadar Lake, the largest freshwater body in the region. The water temperature is a constant 11°C year round and for most of the year this is low enough to cool the building directly, but in the summer months a heat pump can be used to refrigerate the cooling system water to extract additional cooling capacity.

The primary means of cooling the workspace is a network of pipes embedded in the concrete roof slab. The slab is insulated on the outside and the concrete left exposed on the inside to form the ceiling of the offices. Heat from the interior is continuously absorbed into the concrete and any surplus is carried away by the circulating cooling water. This system will operate to deliver background cooling when internal temperatures rise above 22°C.

When the outside air temperature is low enough in the evenings and overnight the slab can simply be cooled by passive night ventilation using the opening windows. However the occupants will need to keep the windows shut during the summer when temperatures can rise to around 40°C for weeks at a time and remain above 30°C overnight. Under these conditions the ground water cooling will operate continuously, supplemented by conventional central air conditioning during the day when the indoor temperature exceeds 26°C

The solar heat gains to the building are mitigated by shading the roof with a photovoltaic solar canopy which, at 86kW, is believed to be the largest building attached photovoltaic installation in the Balkan region. The solar power generation will be sufficient to meet the majority of the building’s power needs. When there is a surplus of electricity generated, this will be fed into the national power grid, another first for Montenegro.

The building is well insulated and uses solar control, triple glazed windows to Passivhaus standards. With the relatively mild Montenegran winters there is typically little call for heating and the idea of heavily insulating the building was unusual for the local contractors. However the insulation pays dividends in limiting heat transmission in the summer and in winter the heat gains from occupancy will generally be sufficient to keep the building warm. However, for the occasions when the temperature does drop, the heat pump can act in reverse to heat the building, drawing heat out of the groundwater. The solar canopy has also had to be designed to withstand 1m snow depth.

When we started the project we unknowingly faced years of trying to persuade the Montenegran construction industry and regulatory authorities of the possibility of delivering low energy buildings in the region. Almost every feature we proposed was “impossible to achieve in this country”. Nevertheless we persisted and with time the awareness of new technologies and techniques grew and, with it, acceptance of what we were proposing. The breakthrough probably occurred when the electricity company changed their rules to allow grid connection of solar PV generation. Thus after eight and a half years the building is finally finished and delivers 95% of the initiatives that we hoped.

This project has clearly advanced the leading edge of building technology in the Balkan region. However, what is most significant is that the final design and construction was realised in Montenegro by Montenegran consultants and contractors, not merely imported from Northern Europe as typically happens. The local development and construction team have gained a huge amount of new knowledge and experience with novel technologies. This is the process I refer to as Co-Design, where we share our knowledge and expertise to enable others to raise their skills and knowledge, rather than simply presenting them with a fait accompli. The building meets European requirements for new buildings to be near zero energy consumers, some five years ahead of schedule and the Montenegran team now has the skills to replicate this indefinitely. This is a key outcome for Montenegro as it seeks membership of the European Union.

We now hope to set up a programme to monitor the performance and use of the building through the first few years of its life. We want to engage both the University in Podgorica and other European Universities in sharing knowledge on how modern architecture can evolve in South Eastern Europe without unnecessarily depleting the region’s resources.