There are multiple LEED certified projects in the region (Middle East) where spaces quality for daylight dimming sensors as per ASHRAE 90.1 mandatory requirements but they are not desgined or installed.

On some projects, reviewers comments are recieved that energy model should reflect the penalty by not modelling the daylight dimming sensor in proposed and modelling them in the Baseline. This approach was accepted on project by project basis.

However no interpretation exists for this approach. From the guides to the Forums, everywhere its clearly mentioned that if space qualifies, daylight sensors are mandatory requirements to be incoporated in the proposed design.

Based on the past projects, we are getting a lot of pushback from design teams on this on every new project. They have done some project in the past which is certified without daylight dimming sensors and want to do same for all the projects.

Do we have any clear guidance on this ? Either this should be mandatory on all the projects or energy modelling penalty approach should be accepted for all the projects.

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Marcus Sheffer

LEED Fellow

7group / Energy Opportunities

LEEDuser Expert

4454 thumbs up

Mon, 12/08/2025 - 20:20

The guidance is very clear on this. Projects are required to adhere to all mandatory provisions. Since these requirements are mandatory, LEED has granted an exception to meeting the mandatory provision that allows projects to take an energy penalty by modeling these requirements in the baseline. It is possible that individual reviewers did not enforce or missed this on a project here and there. They are human after all. There is definitely no except that allows projects to ignore this mandatory provision. So it is mandatory and the exception granted is the modeling penalty approach. The same holds true for the plug load controls mandatory provision. I thought this was in a LEED Interpretation but I could not find it quickly.

Manuel Romera Molina

Energy Efficiency Specialist

PGI Engineering

LEEDuser Basic Member

3 thumbs up

Mon, 12/15/2025 - 07:48

Hello Marcus,Our point of view regarding section G3.1.6 for the Baseline Building is that daylighting controls shall be modelled, at least through lighting schedules. Therefore, we always model daylighting controls for the baseline building, no matter if they are present or not in the proposed design. If they are present, we model it in the energy model for the proposed building too, as designed (in Spain this is the common practice, since they are mandatory per national regulation "CTE DB-HE3"). If they are not present, the proposed model will receive an additional energy penalty.
So we understand that, as any other mandatory control listed under section 9.4., daylight controls should be reflected in the Baseline Building energy model, regardless of whether they exist in the proposed design. Is our interpretation wrong?

Junaid Mujahid

Sustainability Engineer

PNC Architects (Sobha Realty)

LEEDuser Basic Member

2 thumbs up

Mon, 12/15/2025 - 10:59

Hello Manuel,Slightly off topic, but I wanted to know the approach you've used to model daylighting controls with lighting schedule changes only.I've always used RadianceIES in IES-VE to model daylight dimming and have used lighting schedule changes only for occupancy-based lighting controls as it is suggested in 90.1.Curious to know how the same approach applies to daylighting controls since it requires an analysis of some sort into the daylight penetrating into a space.

Marcus Sheffer

LEED Fellow

7group / Energy Opportunities

LEEDuser Expert

4454 thumbs up

Mon, 12/15/2025 - 21:24

Manuel, your interpretation is correct.

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ASHRAE 90.1 mandatory requirement for daylight dimming not met in many projects

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