In order to serve its rapidly expanding population of more than five million, the ArRiyadh Development Authority has commissioned Zaha Hadid Architects to construct the new King Abdullah Financial District (KAFD) Metro Station in its capital city of Riyadh, Saudi Arabia. Best known in Britain for her design of the Olympics Aquatic Centre, Hadid has again envisaged a curved structure, with the station's undulating form supposedly referencing Saudi Arabia's desert sand dunes. Measuring 20,434 square meters in size, the huge space will feature four public floors as well as two levels of underground parking and is intended to function as a gathering place as well as an interchange. A number of gangways and route within the structure will be incorporated to alleviate congestion and the station will also be connected to the Riyadh monorail via a skybridge. Looking more like the inside of five-star hotel, the proposed network, in Riyadh, Saudi Arabia, will boast a space age design featuring marbled walkways, gold-plated walls and, naturally in one of the hottest places on earth, air conditioning. The facade will apparently be designed to let in light while keeping out the harsh desert sun, while the overall shape is meant to recall the country's wind-blown sand dunes. King Abdullah has instructed the new Riyadh Metro be completed in four years. Prince Khaled bin Bander, the governor of Riyadh, said the project is progressing to plan and the ArRiyadh Development Authority has released details of the city's public transport plan including the six metro lines that will serve as the backbone for public transport in the city.

The Dubai Frame, a 150-meter-by-105-meter window-frame like structure in the emirate's Zabeel Park, will be completed by the end of next year. The US$ 32.3 million project, which won the ThyssenKrupp Elevator International Architecture Award in 2009, will feature a museum and is expected to attract up to 2 million visitors per year. The Dubai Frame is intended to highlight both the old and news sides of the city, with newer icons such as the Burj Khalifa visible through one side, and older parts of the city such as Dubai Creek and Deira on view through the other. The structure will be completely transparent, with elevators that will take visitors to a viewing deck located at its peak. A terrace cafe on the top cross-beam and a 150-meter-high glass floor bridge are the major highlights of the project, which will include an observation deck at the top of each vertical shaft. The ground leg of the Frame will include a museum that tells the story of the development of the city and information on its past and present.

As soon as 2014, the Burj Khalifa may no longer be the tallest building in the world. Sky City, a planned 220-story prefab tower in Changsha, China, will soon claim that title. According to Lloyd Alter at Treehugger, Broad Sustainable Building, the company behind the tower, will begin construction on the prefab behemoth this June. The energy-efficient skyscraper will literally house an entire city using just 10 percent of the site area, and it could serve as a model for sustainable urban development of the future. Sky City will be prefabricated off site in three months, and it will then be assembled in just seven months. Reaching up 838 meters, the 220-floor tower will feature residential, office space, organic farms, recreation spaces, schools, a hospital retail and much more. The tower will house 4,450 families in apartments ranging from 60 square meters to 465 square meters with 92 elevators at your disposal to reach them. As its name suggest, Sky City will be a vertical city that will accommodate 100 thousand people and offer everything that is needed - water, electricity, sewage, open space, schools, health care and more. Using just a portion of its site, Sky City will be home to the most extreme urban density we've ever seen. But the difference between Sky City and say, Hong Kong, is that the tower will be surrounded by parks, meaning that every resident will have access to open space. The prefabricated tower will include many energy efficient strategies like 20 centimeter thick insulated walls, triple glazing, exterior shading that cuts down on cooling by 30 percent, and a co-generation plant that will use waste heat from power generation for heating and cooling. Transportation will be provided by low-energy elevators and for those who want to walk (or get exercise) there is a 9650 meters long ramp running from the first to the 170th floor. According to Treehugger, construction is set to begin this June and is expected to be complete within seven months (210 days). The rapid pace of construction and the overall design for such a massive skyscraper could be a cause of concern, but if Broad Sustainable Building pulls it off, it may show the world how sustainable density can be achieved on a massive scale. The company assures that the building will be able to withstand a Magnitude 9 earthquake and will have a three-hour fire resistance rating. Lloyd Alter at Treehugger sums it up well: "This is going to be a controversial vision of sustainability; putting 30 thousand people in a single building is a hard sell. It is not the bucolic version of green living that most people think of. It certainly is a lot higher than what I have called the Goldilocks Density. But it is the logical extension of the Edward Glaeser / David Owen thesis that the way to go green is to go up, reducing the amount of land used per person and the distances people travel." A resident of Sky City will use 1/100th the average land per person as a regular global resident and will use only 2 tons of CO2 compared to 5.5 per capita. Probability that the Broad Sustainable Building Company can afford this unbelievable task is very high. Recall that this is a company which built the 30-story building just in 15 days and a 15-story The ark Hotel - just in 6 days!

Dubai is to build the world's largest vertical garden and the world's biggest butterfly garden as part of an expansion to the Miracle Garden launched in Dubailand earlier this year. As part of phase two, Dubai Properties Group's (DPG) partner Akar Landscaping & Agriculture Company will start work on the latest attractions, which are due to be unveiled in October 2013. In addition to the current variety of plant and flower species, the second phase of the 67 thousand square meters Miracle Garden will include the largest vertical garden in the world. It will also feature an Edible Plants Garden from which visitors can pick their own fruits and vegetables and a Butterfly Garden, made up of an impressive 10 thousand live butterflies bred in the UAE for the first time. The Butterfly Garden, set to be one of the biggest in the world, will be home to over 40 different species of butterfly. A breeding station is also set to be built to manage the butterfly population. Other elements will include new children's attractions, a Flower Hills and Mountains themed garden and a retail area. Currently, world's largest vertical garden is situated in Italy. Last year a shopping centre near Milan claimed an unusual record -- the biggest vertical garden in the world, covering a surface of 1250 square meters with a total of 44 thousand plants.

Dubai's Meydan Group will launch "Meydan Tower", a 111-storey high tower, in the next six weeks, reported the Emirates 24|7. The tower will be located close to Radisson Royal Hotel on Sheikh Zayed Road. "Meydan Tower" is the group's first foray outside its iconic sporting, business and lifestyle destination "Meydan City". The new property will offer residential, commercial and leisure options. The "Meydan Tower" will have one of the largest spa and fitness centers in the region, featuring an indoor running track and tennis courts, while the community tower will house nine pools as well as private and community Sky Gardens. One of the other attractions would be the Club House, located on the top floor, home to a late-night Rooftop Nightclub. In Dubai alone, there are 19 buildings taller than 200 meters and 18 of them are on Sheikh Zayed Road. Burj Khalifa , 828-metres high (160 storey), is the tallest tower in the world, while Princess Tower , 414-metres high (100 storey), is the tallest residential tower in the world.