Planned City Extensions: Masterplanning & Urban Design Principles for Sustainable Urbanisation

This Commonwealth Association of Architects CPD lecture examines the challenge of planning city extensions in an era of rapid urbanization and climate change. Delivered by Alfredo Caraballo from Allies and Morrison, the session uses Madinat Al Irfan in Muscat, Oman as an exemplary case study for sustainable master planning. The project demonstrates how to create a place-specific urban extension that learns from vernacular traditions, responds to extreme climate conditions (temperatures reaching 50°C), integrates landscape and public transport, and establishes governance frameworks for long-term implementation. Through detailed analysis of site conditions, urban structure, typologies, design codes and phasing strategies, the lecture illustrates how master planning can serve as a framework for sustainable urban development that promotes social cohesion, environmental responsibility, economic competitiveness, and public health while creating memorable, distinctive places rather than generic developments.

Outline 

• Introduction to the challenge of rapid urbanization, the generic nature of many new developments, and the need for people-centered planning with strong client vision
• Eleven guiding principles for Madinat Al Irfan including learning from heritage, creating distinct character, pedestrian comfort, integrated public transport, mixed use, celebrating landscape, quality and diversity, phased completion, smart city integration, and catalyzing change
• Five design principles (working with nature, pearls on a stream, gateway location, memorable places, landscape-led design) and five sustainability themes (climate-appropriate design, landscape and ecology, resource use, public transport, governance)
• Site analysis methodology including topography, slope analysis, identification of the wadi (valley) as organizing principle, and distinction between flat downtowns and hilltop villages
• “Anatomy of the city” approach analyzing the project across multiple scales from city to district to block to plot to building to elements, with detailed exploration of microclimatic design, block dimensions, plot subdivision, and building typologies
• Design codes structure covering front matter, site codes, block codes, building codes, element codes, key area guidelines, and integration with local regulations
• Governance models for implementation examining different approaches from single master developer to two-tier planning systems to dedicated development authorities

Learning Outcomes

The sessions learning outcomes were:

• Understand the importance of strong client vision in establishing clear principles from the outset that guide the entire master planning process, including learning from heritage, creating distinct character, and serving as a catalyst for change
• Learn comprehensive site analysis methodology including topography and slope analysis, identification of natural features as organizing principles (such as the wadi), understanding microclimatic conditions, and responding to environmental constraints
• Appreciate the “anatomy of the city” approach that analyzes urban design across multiple scales from city-wide structure through districts, blocks, plots, buildings and architectural elements, recognizing how decisions at each scale affect others
• Understand climate-responsive urban design principles including block orientation to capture breezes, street orientation for shading, building typologies that respond to solar orientation, colonnade and overhang design for pedestrian comfort, and learning from vernacular strategies
• Learn the distinction between creating background fabric and civic buildings recognizing that successful cities require both “res economica” (where people live and work) and “res publica” (civic and landmark buildings) working together to create legibility
• Comprehend the role of design codes in planned city extensions, understanding that codes should establish parameters and performance standards while allowing flexibility, and that they operate across different levels from site-wide to building elements
• Appreciate the importance of public infrastructure and civic space as the organizing framework for successful urbanism, including streets, public spaces, landscape systems, and civic buildings that create structure and identity
• Understand block design principles including optimal dimensions (rectangular blocks maximizing north-south facades), perimeter block configurations, plot subdivision strategies, and how grain size (small, medium, large) creates urban diversity
• Learn about phasing strategies that ensure each phase is complete in itself rather than creating incomplete places waiting for future development, requiring careful planning of infrastructure, public realm and building delivery
• Recognize the importance of governance frameworks for implementing master plans over time, including dedicated development authorities, two-tier planning systems, design review processes, and coordination of multiple approvals

Core Curriculum Topics

• Planning, Places & Communities 
  This session comprehensively covers master planning principles including site analysis, urban structure, public realm design, block and street design, typological diversity, phasing strategies, and the relationship between buildings and spaces at multiple scales.
• Sustainable Architecture
  The lecture extensively addresses climate-appropriate design in extreme conditions, including passive design strategies, orientation for natural ventilation and shading, learning from vernacular architecture, landscape integration, water management, and resource efficiency.
• Inclusive Environments
  The session covers landscape ecology, biodiversity enhancement, water collection and filtration systems, sustainable transport infrastructure, governance for long-term sustainability, and setting benchmarks for future development beyond the site boundaries.

SDG Learning Outcomes

• SDG 11: Sustainable Cities and Communities
  The session directly addresses creating sustainable, inclusive, safe and resilient urban settlements through comprehensive planning, adequate public space, sustainable transport systems, protection of natural and cultural heritage, and universal access to green and public spaces.
• SDG 12: Responsible Consumption and Production
  The lecture addresses efficient use of natural resources, particularly water and energy in a post-fossil fuel context, sustainable management of natural resources, waste reduction, and responsible procurement through governance frameworks.
• SDG 13: Climate Action
  The session comprehensively covers climate adaptation through design, including responding to extreme temperatures, capturing natural ventilation, water management in arid climates, and reducing energy consumption through passive design strategies.
• SDG 15: Life on Land
  The lecture addresses protecting and enhancing terrestrial ecosystems, sustainable use of landscapes, integrating biodiversity into urban planning, and creating continuous green infrastructure through the wadi system and extensive tree planting (31,000 trees).

The following CPD questions forms part of the learning guide for this session. As different Institutions of Architecture across the Commonwealth have different CPD reporting requirements, it is suggested that you retain a copy of your responses to these questions for your records.

1. Client Vision and Principles: How clearly defined are the guiding principles at the start of your projects? What process could you implement to establish shared vision and core values with clients before design begins?
2. Site Analysis Depth: How thoroughly do you analyze site conditions including topography, microclimate, natural features, and cultural context? What additional layers of analysis might reveal opportunities you’re currently missing?
3. Scalar Thinking: Do you consciously work across multiple scales from city to building element? How might the “anatomy of the city” approach improve coordination between urban design and architectural detailing in your work?
4. Climate Responsiveness: How do your projects respond to local climate conditions through orientation, massing, shading, ventilation and landscape? What vernacular strategies from your region could inform contemporary design?
5. Design Codes and Standards: If you were developing design codes for a major extension in your city, what would be the critical parameters to codify versus leave flexible? How would you balance control with adaptability?
6. Implementation and Governance: How do your master plans address long-term governance, phasing, design review, and coordination across multiple stakeholders? What mechanisms ensure vision is maintained through implementation?

To discover more about this project, please feel free to visit:

• https://unhabitat.org/project/planned-city-extensions
• https://unhabitat.org/planned-city-extensions-analysis-of-historical-examples
• https://www.climateaction.org/climate-leader-papers/addressing_climate_change_through_planned_city_extensions