This article is part of the series Home Truths: Europe's Housing Challenge.

The share of the world’s population living in urban areas is set to rise to 68% by 2050 from 55% today, according to the UN, forcing governments around the world to respond. Part of that response has been the creation of new cities. From Forest City in Malaysia to the Norman Foster designed Masdar City in the United Arab Emirates, the race is on to learn the right lessons from the past and build attractive, dynamic, sustainable places of the future.

Songdo, South Korea

Under construction since 2005, Songdo sits about 30 kilometers south west of Seoul, on land reclaimed from the Yellow Sea. Pitched as a city of the future, Songdo was to be an orderly, quiet alternative to bustling Seoul, appealing both to families seeking a calmer life and businesses seeking the latest in high rise office space — all connected to the world by South Korea’s largest airport, across a nearby bridge.

Progress has been stop-start, however, and the completion date has been pushed back repeatedly. Initial estimates for the city’s completion promised 2015. The current date is 2022. Businesses have not arrived as quickly as hoped, and population growth has been slower than anticipated, currently 100,000 residents instead of a hoped-for 300,000.

Forty percent of Songdo’s land is green space, its promoters claim. Much of the infrastructure is centralized, including a state-of-the-art waste disposal system that mostly eliminates garbage trucks, sucking trash to a central processor via a system of tubes. A dense web of bike lanes has been designed to cut reliance on the car. Reports about the feel of the place have been mixed, however, with some describing the rare pleasure of hearing birdsong in a city, while others have called the quiet eerie.

Part of the video for pop megahit ¨Gangnam Style¨ was filmed here, apparently because it was easier to find an empty, quiet spot to shoot than in actual Gangnam, back in Seoul.

Masdar City, United Arab Emirates

Initiated in 2006, Masdar City’s planners envisioned it as the world’s first zero-carbon city. Unfortunately, the scorching local heat, which places unusually high demands on electricity production, have planners dialing that promise back and aiming for “low carbon.”

Some of the city’s other initiatives have worked better. Designed by Norman Foster, the architect behind Wembley Stadium in London and Apple Park in California, the city’s streets are laid out to increase shade and feature towers that draw down a cooling wind. Use of private vehicles is tightly restricted. The city houses a number of research institutes focused on developing green technology.

Though progress has been much slower than expected, planners expect 50,000 residents by 2030, plus a daytime population inflated by 40,000 commuters from places like nearby Abu Dhabi. The city has drawn some praise for contributing to planners’ understanding of how to develop sustainable communities. But with its high walls, it has also drawn criticism, with critics saying it looks like an entire city built as a gated community.

Eko Atlantic, Nigeria

This new urban center on Nigeria’s southeast coast, just outside Lagos, is planned as a regional financial hub, providing housing for 250,000 people and work for 150,000 daily commuters. Built on ten square kilometers of land dredged from the sea means it also has an eight-kilometer seawall made of five-ton concrete blocks, to protect (hopefully) against flooding.

The city's developers, the Chagoury Group, claim the project will help alleviate a chronic shortage of real estate in one of the world’s fastest-growing megacities. Critics say the high end project risks leaving Lagos’ urban poor behind. Other concerns say the city’s footprint could make flooding worse elsewhere along Nigeria’s coast.

Forest City, Malaysia

Located at a strategic point at the tip of the Malaysian peninsula, the $100 billion “emerging futuristic urban development” sits close to regional hub Singapore. Much closer than capital Kuala Lumpur.

Originally envisaged as a “vibrant city...synchronized with the world”, the development has become a political flash point between Kuala Lumpur and Beijing, after 94-year old Malaysian leader Mahathir Mohamad moved to curtail foreign buyers from investing in the development. Led by the Chinese developer Country Garden Pacificview and a Malaysian government-backed entity, many early buyers are Chinese nationals, and much of the funding for the building has been Chinese, drawing Mahathir’s ire.

Built on four artificial islands, Forest City aims to house 700,000 residents in what backers call a technologically-advanced, environmentally-friendly setting.

Indonesia’s new, yet-to-be-named capital

Indonesia’s president last month announced plans to build a new capital on an out-of-the-way patch of the island of Borneo seeking to alleviate some of the strain on the overcrowded current capital of Jakarta, which is rapidly sinking into the sea as residents draw water from the aquifers which support it.

Plans for its design of the new city, which was mooted for decades, are sketchy so far. Though it has yet to be given a name, the government expects it to have 200,000-300,000 residents within five years, and Indonesia’s planning minister told Reuters lessons would be learned from Seoul, Singapore and Washington.

Concerns are already being expressed about what the new administrative center will mean for the natural environment on Borneo, home to many rare species, including the orangutan, and already subject to rapid deforestation. Indonesia wouldn’t be the first country to build a new capital from scratch. Similar projects have been executed in countries across the world from Brazil to Myanmar to Australia and the United States. The new city is expected to cost Indonesia around $33 billion.