• daylight in schools slide

    Daylight in Schools

    Designing schools for the future

Daylight Design for Schools

In 2014, the Education Funding Agency (EFA) Priority School Building Programme (PSBP) adopted Climate-based Daylight Modelling (CBDM)  as a new approach to daylight design in schools.

Historically, traditional daylight design within schools has focused on the adequacy of illumination, by means of measuring the Daylight Factor (DF%) under CIE Overcast sky conditions, aiming to deliver a certain percentage of diffuse light into classrooms and to maintain a certain level of uniformity.

In contrast, CBDM uses local weather files to analyse the annual illuminance throughout the year, under varying sky conditions, using two dynamic daylight metrics; Spatial Daylight Autonomy (sDA) and Useful Daylight Illuminance (UDI).

Spatial Daylight Autonomy - sDA(300/50%)

  • The Spatial Daylight Autonomy (sDA) should be 50% or greater across at least 50% of the working plane during occupied hours. The target illuminance (typ. 300lux) should be achieved for more than 50% of the time throughout a typical year during occupied hours (8.30 am to 4.00 pm) across at least 50% of the working plane

Useful Daylight Illuminance - UDI-a (100~3000lux)

  • The UDI-a (100-3000lux) should be >80% (ave) across the working plane during occupied hours. The level of illuminance provided below 100 Lux (UDI-s) and above 3000 Lux (UDI-e) should occur no more than 20% of the time (ave).

Services

Lighting Analysts are pioneers in the use and application of Climate-based Daylight Modelling, with over 20 -years experience in daylight simulation and analysis.

Over the past 8 years, we have worked on over 115 new school developments across England, working with leading architects and construction companies as part of the government (DfE/ ESFA / EFA) Priority School Building Programme (PSBP).

Our in-house systems and processes enable us to work directly from the architectural 3D Revit model, carrying out in-depth complete building analysis.

CBDM Compliance

DfE GDB (2021)

The Department for Education (DfE) issued a revised Generic Design Brief (GDB) in November 2021. There were no changes made to the Annex 2E daylight requirements, in terms of the sDA and UDI-a targets.

The L1, L2 and L3 compliance targets remain the same as the GDB Annex 2E 2017 edition:

Type L1 - Basic teaching

  • 80% of L1 spaces are required to achieve both the sDA(300/50%) and UDI-a (100~3000lux) targets. 

Type L2 - Hall Dining PE & Libraries

  • 65% of L2 spaces are required to achieve the Useful Daylight Illuminance target.

Type L3 - Group, study areas & staff rooms

  • 50% of L3 spaces are required to achieve the Useful Daylight Illuminance target.

 

DfE GDB (2019)

The Department for Education (DfE) issued a revised Generic Design Brief (GDB) in May 2019, which results in a minor change to the Annex 2E daylight requirements.

The L1 targets remain the same, but the L2 and L3 compliance targets were lowered to 65% and 50% respectively.

Type L1 - Basic teaching

  • 80% of L1 spaces are required to achieve both the sDA(300/50%) and UDI-a (100~3000lux) targets. 

Type L2 - Hall Dining PE & Libraries

  • 65% of L2 spaces are required to achieve the Useful Daylight Illuminance target.

Type L3 - Group, study areas & staff rooms

  • 50% of L3 spaces are required to achieve the Useful Daylight Illuminance target.

 

ESFA PSBP (2017)

The Education & Skills Funding Agency (ESFA) Priority School Building Programme 2 (PSBP2) Generic Design Brief (GDB) 2017 defines six space types (L1 - L6) each with their own set of requirements for daylight compliance. Primarily, space types L1 - L3 requires analysis via CBDM:

Type L1 - Basic teaching

  • 80% of L1 spaces are required to achieve both the sDA(300/50%) and UDI-a (100~3000lux) targets.

Type L2 - Hall Dining PE & Libraries

  • 75% of L2 spaces are required to achieve the Useful Daylight Illuminance target.

Type L3 - Group rooms study areas & staff rooms

  •  60% of L3 spaces are required to achieve the Useful Daylight Illuminance target.
EFA PSBP (2014)

The Education Funding Agency (EFA) Priority School Building Programme (PSBP) took a new approach to the design and analysis of daylight within schools.

The EFA Daylight Design Guide Rev 2 2014 and Facilities Output Specification (FOS) required:

Teaching & Learning Space

  • 80% of the Teaching & Learning Spaces, within new build projects, must meet the minimum targets for both Spatial Daylight Autonomy (sDA) and Useful Daylight Illuminance (UDI).

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