Step 3: Determine building typology’s material composition
Goal: Determine the material composition (in t/m2), which are typical types of materials and their amounts for a typology, for each building typology of Step 2.
Situation: The varying material compositions need to be carefully accounted for, as the different construction methods (of the various building typologies) have different material needs and material “density”. For instance, low rise and high rise residential buildings do not have the same structural needs. High rise buildings will have a tendency to be more material intensive per m2 (especially for the structure). In addition, the year of construction can also be crucial, as for example certain materials such as asbestos or lead used to play a more significant role, compared with today or reinforced concrete may play a larger role than bricks now. Depending on the country, and even the region, the material composition can be quite distinct, depending on availability of local materials, stage of economic development, building methods, climate, etc. Therefore, each building typology has a material composition associated with it in t/m2 that needs to be found.
For determining the material composition or also material intensity, a couple of options exist:
- Obtaining the original bill of quantities of one building typology from large construction companies that have had a presence in the city for a long time.
- Getting architectural plans of a building typology and pictures to roughly estimate the materials used per m2.
- Receiving architectural plans from new constructions, which may be more easily available, especially those built for the city departments or those that use newer typologies.
- Consulting existing scientific articles or case studies, for which you can do a keyword search (see below for some examples and tips).
- Using old architectural magazines or old urban development books that state which and how materials were used during a certain period of time.
- Performing a visual inspection and measuring surface area and thicknesses of materials.
- Employing good data of sorted waste from a building that was demolished from a certain typology and reverse engineering the material intensities (t/m2).
- If available, using material audits conducted by cooperatives or real estate companies of their buildings, preferably in a Building Information Modelling (BIM) format. These are different from pre-demolition audits, which often just focus on the small amount of materials that are going to be reused.
Sprecher et al. (2022), “present a database on the material intensity of the Dutch building stock, containing 61 large-scale demolition projects with a total of 781 datapoints, representing more than 306,000 square meters of built floor space”. (See article “Material Intensity Database for the Dutch Building Stock: Towards Big Data in Material Stock Analysis”), page 567.
For Norway, you can refer to “Dynamic material flow analysis for Norway's dwelling stock”.
For Brussels, there exists a table for three typologies and seven material groups in the publication “Économie circulaire dans le secteur de la construction à Bruxelles”, see Table 6 on page 31:
- Typology 1: Row housing (traditional row housing in Brussels from the 19th C. (left)
- Typology 2: Apartment buildings from the 1960s (middle)
- Typology 3: Office buildings from the end of the 20th C. (right)
For Melbourne, here are some other figures from the article on ”Quantifying and mapping embodied environmental requirements of urban building stocks”, kg/m2.
Tips for searching of material composition / material intensity in publications
- Material intensities can be found in publications, sometimes under Supporting information at the end of the paper.
- Try a keyword search of the following combinations, together with your country name (city name can also work but might be unlikely to get results):
- Material intensity + Country/City
- Material intensity building + Country/City
- Material stock composition + Country/City
- Building stock composition + Country/City
- Try these searches of course also in the local language.
- Aside from a search engine, do the search in the following pages: