SETTING A DAYLIGHTING GOAL
The planning process varies in focus depending on your goals and business model as a design firm, and of course on the details of the project. In some cases, the planning phase will be split across multiple stages and is developed with significant time investment. In others, a more pragmatic, simplified approach is sufficient to deliver what is needed.
Wherever a project sits on this scale, considering daylight at an early stage, and including daylighting goals in the brief, can create significant value.
KEY LEARNINGS
- Understand how daylighting fits into initial project/site investigations.
- Understand how to use daylighting goal to set objectives for the project design in dialogue with your client/s.
- Define key steps that can be followed to set a daylighting goal, including setting specific room-based targets.
Investigating and understanding through data Data collection may seem like an odd term, but it is an apt description for what you do when you start work on a new project1.
Your initial investigations are geared towards understanding the client, the intended building occupants and the activities that will take place in the building, closely followed by the building site.
Investigation into site details typically starting with the climatic conditions – sun path, sunlight hours, climate, microclimate, wind, and temperatures – followed by the geography of the site, including soil conditions, available views, and existing ecosystems and activity on or around the site.
Alongside this comes the less visible or tangible observations that may be layered on the site, including political, social, cultural or economic ‘stories’ or history.
Overarching all of these themes is the legal framework of planning restrictions, building regulations or codes, rating schemes, and any other standards that apply to the area.
All of this is ‘put into the blender’ to be assessed and understood in relation to one another and the initial brief. Priorities are established, a synthesis begins to occur and design ideas start to form – including daylighting strategies.
Basic questions to answer during your data collection phase
- What is the frequency of sunlight hours on the site?
- What is the impact from reflected light sources (eg. are there particularly reflective neighbouring buildings)?
- What is the impact of natural / geographical factors on this site in relation to daylighting potential?
- What are the relevant local laws and guidelines related to daylighting for buildings?
- Who will the occupants of this building be, and what kinds of tasks will take place?
- What are the differing needs and desires for daylight between spaces in the project?
- Is it desirable to create unique daylighting effects or experiences in any specific areas (special diffuse lighting, graphic patterns from shadows, uniformity etc.)?
- Are there particular views to capture (do these create any tensions with optimal orientation in relation to daylighting)?
- How can daylight support larger project goals (social, environmental, or economic)?
Defining a strategy early on: the value of setting a strategic design concept Before putting pen to paper with sketches it’s worth considering whether writing a ‘return brief’ – including your recommendation on strategic priorities and goals for the project – would bring value.
By starting out with clearly defined goals you have a clear reference point to come back to if difficult decisions are faced further on and choices need to be made between different design options. These strategic goals would be based on what you discover through the analysis and synthesis of the data you’ve gathered on the project site and client, bringing together the key elements in a clear vision.
Superkilen in Copenhagen. Photography: Astrid Rasmussen. Architects: BIG & Superflex
Setting strategic daylighting goals When daylighting is a key part of your strategic design concept – not only in ‘standard provision’ (amount of daylight), but by connecting it to its many benefits (health, sustainability, experiential quality) – it can open a certain design freedom at later stages to explore what may have otherwise been deprioritized by the client.
Strategic goals that have a strong correlation with daylighting could include the following:
- Improve the health of the building’s occupants (family living in the home, workers in the office etc.)
- Improve the productivity of the building’s occupants (students in a classroom, workers in an office etc.)
- Lower the CO2 emissions of a project across all lifecycle phases (material procurement, construction, use and maintenance of building, end of life).
- Create additional revenue streams through valuable design choices (allow a school to rent out beautiful, daylit, recreational spaces to the public in non-school hours, or a family to rent an ‘independent’ part of their home as their needs change).
- Improve student engagement rates (a university project where existing classes have noted high rates of students working off-site and not engaging in student life – your new design brief could consider the types of spaces in which students are willing to gather and how daylight could be a key driver in defining those spaces)2.
Defining room- or activity-based daylighting goals In addition to the overarching strategic goals, that daylighting will surely be an element of, it is worth diving a little deeper into the daylighting requirements for different spaces within a project and setting some specific goals or priorities.
Combining your daylight expertise together with the European daylighting standard EN17037 will provide a solid foundation for defining these specific goals. Like any design standard, EN17037 requires nuanced interpretation to become a practical and useful tool for architects and designers. So, when setting out to define room or activity-based goals for your project it is recommended that you have your extended project data and context at front of mind to determine the most appropriate performance level and relevance of design areas (daylight provision, views to the outdoors, sunlight levels, and glare) for the different spaces. An example of how this could look is presented in the design card below.
Many different factors define how any given room or space in a particular building will be used. Two buildings with similar types of rooms, intended to have similar functions, could easily see those rooms used in completely different ways, simply through the different expectations or attitudes of the users.
It can therefore be difficult to give a defined series of steps that can be followed to set room-based goals or targets – it will of course always depend on project specific data what is relevant.
Additional questions and considerations you may wish to discuss with your client are detailed below:
Does lighting uniformity suit the activities in the space you are designing?
- A certain level of uniformity is highly beneficial if the same type of activity should be possible in multiple locations within one room For example, a traditional classroom with individual student desks throughout
- However, diversity in lighting can be highly effective to support diversity in activity and user preferences. For example, an office that provides workers with a choice of workspaces away from a fixed desk, can call for a lighting design that provides a mix of brighter and low-lit spaces: A meeting space primarily used for presentations with projectors can have limited daylight, whilst a breakout atrium space could provide over 1000lux using daylight as the primary source to a work plane used for workshops, drawing, or reading.
Does your local regulation provide a choice of how you meet minimum daylighting standards?
- Consider if this minimum is really adequate. If you want the benefits of good daylighting in your project you may need to push beyond minimum standards. Think ‘performance’ rather than ‘compliance’. For example, in Denmark it is possible to choose between two methods of daylight documentation: a 10% glass to floor area ratio (see here for why we don’t recommend this ratio as a metric), or a 300-lux rule, which is more closely aligned to EN 17037.
Who will be responsible in the project for documenting daylighting performance?
- If your project has a contractor on board from the start, they might wish to take on the responsibility of documenting that the project meets daylight minimum requirements. Typically, they will choose the 10% glass to floor area rule – it is what they know, and it often makes for a lower build cost by minimizing glass in facade.
- It is important, when possible, to take on the responsibility for compliance with daylighting – and to do it using climate-based metrics where possible.
Summary
The following steps provide a useful guide that can be followed on any project to aid in establishing daylighting goals.
- Establish specific project needs and requirements through ‘data collection’ and analysis.
- Define your strategic design concept and ambitions. What are the core, measurable aims of the project?
- Refer to EN 17037 and consider specific room- or function-based goals for its different aspects.
- Establish whether other standards or rating schemes are, or should be, part of the project ambition.
- Incorporate as much of this detail as possible into the project brief shared with your client, and consider producing a ‘return brief’.
Working closely with clients The processes and ideas presented above give you a method for working that allows you to engage more easily with your clients. They give you the tools to enter into a dialogue about their daylighting goals, and how those goals can be translated into specific design decisions. This way, the end goal for daylighting is introduced early in the design process and can be referenced throughout the project. Established goals and priorities from the outset makes it more difficult to ‘cost cut’ later in the process.
1 Strømann-Andersen, Jakob (2022) Discussion with Henning Larson Architects on working with daylight. 23rd March. 2 Strømann-Andersen, Jakob (2022) Discussion with Henning Larson Architects on working with daylight. 23rd March.