BREEAM 2018 LCA on mixed use buildings

[Henrique Mendonca]

What is the LCA scope for a ground floor retail unit in a large mixed-use building?

[admin]

(pasting BRE’s response here – Jordan Magee)

Under BREEAM UK New Construction 2018 Mat 01 the building LCA scope must include the whole building design even if the area covered by the BREEAM assessment is only part of the design.

The BREEAM LCA benchmark is expressed as a value in BRE EN EcoPoints per functional unit (e.g. 2.5 BRE EN Ecopoints/1m2 (net internal area)).

Therefore, even when a large development is being assessed the comparison to the benchmark is still proportional to the floor area. In addition, if the building’s net internal area is <50% either office, retail or industrial then ‘mixed-use’ shall be selected as the building type in the Mat 01/02 Results Submission Tool. Then no building LCA tool can be selected for comparison with the BREEAM benchmark – only options appraisal can be done (with no penalty in the credits available). Therefore, for a small retail (<50%) unit within a large residential development this would not be compared against the benchmark.

If the building’s net internal area is ≥50% either office, retail or industrial then that use type shall be selected in the Mat 01/02 Results Submission Tool. A building LCA tool may then be selected for comparison with the BREEAM benchmark. That’s single functional use of ≥50% not for example office 25% and retail 25%. The total building area that should be entered in these cases.

[Fei Ngeow]

To translate the above simply – in mixed function buildings, the way to determine the type of benchmark used to compare with the whole building being assessed, is to use whichever function that takes up ≥50% of the building’s net internal area.

For example, if the NIA for a mixed use building is 85% residential and 15% commercial, the whole building will be compared with a residential benchmark. If the NIA is 50% commercial, 25% retail & 25% residential then a commercial benchmark will be used.