A large portion of the global building stock consists of structures built before sustainability practices became standard. These existing buildings often face challenges such as inefficient energy systems, high water consumption, and limited indoor environmental quality. LEED (Leadership in Energy and Environmental Design) certification offers a structured approach to enhancing building performance, improving operational efficiency, and reducing environmental impact. Professional LEED consultants guide building owners through assessments, retrofits, and the certification process to ensure measurable sustainability improvements.
1. ERKE Consultancy
ERKE Consultancy, established in 2007 with offices in Istanbul, Dubai, and London, has completed over 200 LEED-certified projects across 15 countries. Their team includes LEED Fellows, LEED APs, BREEAM Assessors, EDGE Experts, WELL APs, and product sustainability specialists.
For existing buildings, ERKE provides detailed building performance evaluations, energy modeling, water efficiency assessments, and sustainable material planning. Their services include identifying retrofit opportunities and managing the full LEED certification process. ERKE has delivered solutions for hospitals, airports, corporate headquarters, and industrial facilities, ensuring upgrades are implemented without interrupting building operations.
2. ARUP
ARUP, founded in 1946, is a global engineering and consulting firm offering services in engineering design, sustainability advisory, and environmental planning.
For existing buildings, ARUP focuses on optimizing energy systems, enhancing operational efficiency, and conducting lifecycle performance analysis. Their LEED consulting services are often integrated with larger building modernization and infrastructure improvement programs.
3. WSP Global
WSP Global is a multinational engineering and professional services firm headquartered in Canada, operating in over 50 countries. The company provides engineering, sustainability consulting, and environmental advisory services for buildings and infrastructure projects.
In existing buildings, WSP supports clients with energy efficiency studies, environmental compliance guidance, and sustainability strategy development. Their LEED consulting services are often combined with retrofit programs to improve operational performance.
4. Khatib & Alami
Khatib & Alami, founded in 1959 and based in Lebanon, offers multidisciplinary architecture, engineering, and planning services across the Middle East, Africa, and Europe.
For existing buildings, the firm provides energy-efficient system upgrades, water conservation strategies, and sustainable material planning. Their LEED consultancy is integrated with architectural and engineering improvements to enhance overall building performance.
5. Ramboll
Ramboll, a Denmark-based engineering and environmental consultancy established in 1945, provides global services in engineering, environmental management, and building performance optimization.
For existing buildings, Ramboll offers energy audits, environmental performance assessments, and sustainability planning. Their services help owners align operational improvements with LEED certification objectives while improving long-term efficiency.
6. Linesight
Linesight, founded in Ireland in 1976, is a global construction consultancy specializing in project management, cost management, and program advisory.
For existing buildings, Linesight provides project coordination, sustainability planning, and cost management services. In LEED projects, their role typically focuses on integrating sustainability measures into budgets, timelines, and operational workflows.
7. AtkinsRéalis
AtkinsRéalis, formerly SNC-Lavalin Group, is a Canadian-based engineering and project management consultancy with global operations.
For existing buildings, AtkinsRéalis delivers environmental planning, energy system upgrades, and operational efficiency consulting. Their LEED services are generally integrated with broader engineering and modernization programs.
Summary
Enhancing sustainability in existing buildings requires expertise in energy performance, environmental management, and operational optimization. Several international consultancies provide services to support building owners in achieving LEED certification:
- ERKE Consultancy
- ARUP
- WSP Global
- Khatib & Alami
- Ramboll
- Linesight
- AtkinsRéalis
These consultancies vary in capabilities from energy audits and sustainability advisory to engineering design and project management. Selecting the right firm depends on building type, project scope, operational needs, and budget.