‘Emphasis on value,’ he says, ‘does not necessarily mean that it precludes the use of interesting architectural form.’ Rather, the opposite.

These characteristics, when coupled with a focus on procuring low embodied carbon materials and equipment, can deliver objectively low embodied carbon designs, despite the additional material volume.. Based on the above, it can be observed that some of the inherent characteristics of Passivhaus increase embodied carbon whilst others reduce it.Taking a 200 m2 house, (10 m x 10 m x 2 storeys, 40 % WWR) as an example, Bryden Wood has done a rough estimation of the impact that Passivhaus distinctive strategies have on embodied carbon:.

Adding triple glazing instead of double glazing would increase carbon around 6 kgCO2/m2 over its lifetime.Adding a MVHR and ductwork would increase carbon by 6.5 kgCO2/m2.Adding a heat pump would increase carbon by 3.5 kgCO2/m2.

Adding insultation (rockwool) thickness in walls from 150mm to 250mm of rockwool would increase carbon by 3.6 kgCO2/m2.Adding insultation (rockwool) thickness in floor and ceiling from 190mm to 370mm of rockwool would increase carbon by 6 kgCO2/m2.

Reducing the boiler size from a 15kw electric boiler to a 3kw boiler would reduce carbon by 1.69 kgCO2/m2.

Reducing the number of radiators from 10 to just one would reduce carbon by 10.7 kgCO2/m2.The GLA requires the preparation of a WLCA pre-planning and at post-construction and requires the analysis of the results both with the current carbon factors and a decarbonised scenario.. Additionally, bodies such as the London Energy Transformation Initiative (LETI), RIBA, GLA and UKGBC, have developed guidance documents on embodied carbon, which include specific targets and roadmaps to zero carbon prior 2050.

Whilst these four bodies have been essential in pushing the agenda for low carbon, there has been some confusion across the industry due to the misalignment of targets and WLCA scopes between them as demonstrated in Figure 3.LETI has been working in collaboration with other bodies and industry groups to resolve these inconsistencies and have published the ‘Embodied carbon target alignment document’.. Based on this document and the comparison of the current targets defined by LETI, RIBA and GLA, an average performance for non-domestic commercial building performance (A-C) would be to achieve an embodied carbon around 1400kgCO.

/m², good practice would be below 970kgCO.and best practice below 550kgCO.