How Daylight Sunlight Assessments Support Different RIBA Stages

The RIBA Plan of Work [1] is the UK document that is used to categorise a project from its initial stages of planning to the completion of the site. It was developed by the Royal Institute of British Architects, and it breaks the project lifecycle into eight stages (0 to 7). Each stage gives a set of outcomes, and the stages are used in most construction projects for design, construction, and use.

Overview of the RIBA Stages

The Eight RIBA Stages are [2]:

• Stage 0 – Strategic Definition: This stage is for establishing the case and setting the foundation of the project. The project’s viability is checked before design work begins. 
• Stage 1 – Preparation and Briefing: This is where the project brief is done, and the information is gathered needed to inform the design chain. The budget and client requirements are developed alongside the timeline.
• Stage 2 – Concept Design: At this stage, initial design options are produced and reviewed against the brief with the client and various stakeholders to check if the project aligns with building regulations.
• Stage 3 – Spatial Coordination: At stage three, the design is then coordinated across all the disciplines to support planning applications.
• Stage 4 – Technical Design: This is where detailed technical information is provided to start construction.
• Stage 5 – Manufacturing and Construction: The physical works are carried out on site.
• Stage 6 – Handover: The project is completed and is being transferred to the client.
• Stage 7 – Use: The last stage is operating and maintaining the completed site.

Where Daylight and Sunlight Assessments Fit In

Daylight Sunlight assessments are relevant across the entire design process, from early layout and orientation decisions to planning submission. The scope and detail of the assessment are determined by the current RIBA stage.

• Stage 0-1: Early-stage Daylight and Sunlight assessments can establish constraints regarding the site. They can also be undertaken at this stage to test how the site might affect neighbouring properties, and flag potential overshadowing issues before they become embedded in the design.
• Stage 2: As design options are developed, a daylight and sunlight assessment could be used to determine whether each design option affords sufficient daylighting to each room in the plan. Where design options concern the footprint of the building, the assessment can give an early indication of the overshadowing caused by each one to neighbouring buildings.
• Stage 3: This is typically where formal Daylight and Sunlight reports are produced to support planning applications, providing coordinated technical evidence (Vertical Sky Component (VSC), Annual Probable Sunlight Hours (APSH), No Sky Line (NSL), and overshadowing diagrams) in support of the daylight and sunlight assessment.
• Stage 4: As technical design progresses, Daylight and Sunlight inputs may be revisited to confirm that detailed design changes (window positions, balcony depths, façades) haven’t adversely affected daylight or sunlight performance compared to the planning submission.

Pager Power’s Daylight Sunlight Assessment Support

Our Daylight Sunlight Assessments are conducted according to the BRE Guidelines (BRE 209), as well as British Standards, and are delivered in accordance with local planning authority requirements within the UK. We can support projects during RIBA Stages 0 – 4, advising on daylight, sunlight and overshadowing considerations throughout the planning and design process.

About Pager Power

Pager Power undertakes technical assessments for developers of renewable energy projects and tall buildings worldwide. 

For more information about what we do, please get in touch.

References

 [1] “RIBA Plan of Work.” Accessed: Jun. 15, 2026. [Online]. Available: https://www.riba.org/work/insights-and-resources/riba-plan-of-work/

[2]  afl-admin, “The RIBA Plan of Work 2020 and RIBA stages,” Architecture for London. Accessed: Jun. 15, 2026. [Online]. Available: https://architectureforlondon.com/news/the-riba-plan-of-work/