England · Statutory guidance
Conservation of fuel and power: Approved Document L, Volume 2 — Buildings other than dwellings
Energy performance guidance for non-domestic buildings, covering fabric, services, controls and commissioning.
- Edition
- 2021 edition incorporating 2023 amendments · Volume 2; later editions and transitions on source page
- Search coverage
- 116 of 116 PDF pages · 2 OCR pages
Energy & sustainability
Open original PDF at page 102 Source wording and page order preserved. Drawings and table layouts remain available in the original PDF.
AB O N L I N E V E R S I O N
Step 9: Calculate total energy (kWh) per square metre per year (LENI).
The total energy per square metre per year is the sum of the daytime, night-time and parasitic
energy uses per year divided by the area (A), as set out in the formula below.
E + E + E
LENI (%) = p d n
A
Table B1 R ecommended maximum LENI (kWh per square metre per year) in new and
existing buildings
Hours Illuminance (lux) Display lighting
Total Day Night 50 100 150 200 300 500 750 1000 Normal Shop
window
1000 821 179 0.69 0.68 2.57 3.00 3.96 5.93 8.83 12.59 2.50
1500 1277 223 1.04 0.98 3.05 3.68 5.10 8.00 12.33 17.98 3.75
2000 1726 274 1.39 1.28 3.54 4.37 6.26 10.10 15.85 23.40 5.00
2500 2164 336 1.73 1.60 4.04 5.07 7.43 12.23 19.41 28.85 6.25
3000 2585 415 2.08 1.93 4.56 5.81 8.64 14.41 23.04 34.36 7.50
3700 3133 567 2.56 2.42 5.34 6.90 10.42 17.59 28.27 42.22 9.25
4400 3621 779 3.05 2.97 6.20 8.08 12.33 20.95 33.73 50.27 11.00 24.20
5400 4184 1216 3.74 3.87 7.58 9.98 15.32 26.16 42.02 62.24 13.50
6400 4547 1853 4.44 4.94 9.22 12.19 18.73 31.99 51.06 74.87 16.00
8760 4380 4380 6.07 8.36 14.33 18.99 28.89 48.85 76.21 108.14 21.90 48.18
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O N L I N E V E R S I O N
Edition and local adoption determine which requirements apply. Use the publisher’s document for the complete clauses, diagrams and amendments.