The built environment is the world’s largest industry, and one of its least recognised. It is a $380 trillion asset class. It sustains a quarter of a billion jobs. It accounts for a third of all global energy use and carbon emissions. It produces some $13 trillion of construction output every year.1 No other sector comes close in scale, permanence, or consequence, and it is also the world’s single largest investment opportunity. Yet it has long operated as a collection of disciplines, asset classes, and professional silos rather than as the unified force it is, and it has lacked a clear collective voice and a shared agenda. 

This Declaration is not the work of a few institutions speaking for the rest. It is an open agenda, offered to everyone who plans, designs, finances, builds, operates, and governs the world’s cities, and an invitation to make its commitments their own. It looks forward by design. It sets out not what the sector has achieved but what it now intends to do, and it asks every professional and every organisation in the built world to support it and to act on it in their own work and their own places. 

The long expansion that has shaped cities for a century is giving way to a new era defined less by growth than by reinvention. In many places the task is no longer to build more but to adapt, retrofit, and renew what already exists. Where new cities and districts must still be built, they should be more frugal, more flexible, and more resilient than their twentieth-century predecessors. Meeting this will require long-term capital, patient stewardship, and a quality of leadership the sector has not always been asked to provide. 

We therefore commit ourselves, our organisations, and our profession to five shared imperatives. 

Adaptation. We will prioritise the reuse, retrofit, and renewal of what we have inherited, treating the existing city as an asset to be stewarded rather than a constraint to be replaced. 

Resilience. We will design, finance, and operate cities to withstand climate, economic, and social shocks, and to recover and improve in their wake. 

Flexibility. We will plan and build for change, creating places and assets that can adapt to uses, technologies, and needs we cannot yet foresee. 

Frugality. We will use land, materials, energy, and capital with discipline, delivering more value and better outcomes from fewer resources. 

Leadership. We will provide the long-term, cross-sector leadership and learning needed to align capital, climate, and collective prosperity, and to shape better cities and better outcomes for those who follow. 

This agenda is offered in support of the wider global effort to make urbanisation work. In July 2026, ten years after the New Urban Agenda was adopted in Quito, the United Nations convenes the midterm review of its implementation, and member states will renew their commitments to sustainable urbanisation through to 2036.2 The Built World Declaration is the contribution of the professions to that moment. Governments set the framework, but it is the people who finance, design, build, and operate cities who turn commitments into outcomes. We intend to be accountable for our part. 

Commitments of this kind need a practical vehicle to carry them. The NLA’s Built World Exchange provides one: a means of connecting professionals and cities across the planet so that the leadership challenges set out here can be addressed in common, through shared learning, comparison, and practical collaboration rather than through declarations alone. 

What this looks like in a single city is already visible in London. The New London Agenda, NLA’s framework for best practice in city-making, translates these same principles into a shared programme for one city’s built environment community as it enters a new development cycle.3 It is offered here not as a template to be copied but as an example of how a global agenda can be made specific, owned, and acted on in any city, by the people who shape it. 

This Declaration will not solve every problem, and it does not pretend to. But it places, for the first time, a coherent set of commitments on the table, and it asks the professionals of the built world, in every city and every discipline, to adopt them as their own. We undertake to act on these commitments, to measure our progress against them, and to return to them in the years ahead as a shared standard against which our leadership can be judged. 

Made at Guildhall, London, on 29 June 2026, and offered to all who shape the world’s cities.