The existing area, block and/or lot-specific data bases on housing and work-place heating have been compiled for graphic representation of the block or block-segment level. Of the approx. 25,000 statistical blocks and/or block segments of the Environmental Information System (UIS) of the Berlin Department of Urban Development and Environmental Protection, those which show an at least predominant structural use have been shown on the map. The figures recorded for the entire block were transferred to all built-up segments according to their area share of the block (cf. Map 06.01, SenStadtUm 1995e).
The representation of the results on two separate maps is designed to show clearly both an overview of the break-down by energy carrier (Map 08.01), and the fuel used on the respective block and/or possible mixed supplies (Map 08.02). Map 08.02.1 shows the most important district heat production sites. The fuels used for residential and work-place heating were grouped together under five heating types: district heat, gas, oil, coal and nighttime power storage heating.
On Maps 08.01.1 to 08.01.4, the heating types district heat, gas, oil and coal are shown. The proportional share of each fuel in the total heated area of the block is represented, provided that share is at least 5 %. Buildings heated by nighttime power-storage heating are not shown separately, because of their small overall share (1.2 % of the total heated area).
The representation of each fuel is accomplished with the same coloring. Lighter shades represent less densely-built blocks (less than 5,000 m2 of heated area), combined with a slighter share of the energy carrier concerned for the overall heated area; conversely, the darker shades show densely populated areas and the dominating influence in the block of the respective fuel shown on the four single maps (15,000 m2 or more heated area).
On Map 08.02 – Predominant Heating Types, the characteristic type of heating for each block is shown. The color shadings for all five fuels, from yellow for natural gas to purple for coal is designed to show the increasing share of air pollutant potential for each material. A special problem involves the district-heating supply. Of course, no emissions occur at the consumer level from these 35 district-heating networks run by different enterprises, but the fuel use at the point of production is what is significant. This can be seen for selected plants on Map 08.02.2.
A heating type is shown as predominant if its share of the heated area in the block totals more than 40 % and the difference to the second-highest fuel used in the block is greater than 20 %. For the differentiation of the proportional shares between 40 and 100 %, a linear percentage class division is undertaken, with three levels. These levels are shown by means of a graduated coloring within the primary color.
If no predominant heating type is indicated on the basis of the distribution of proportional shares of heating types in a block and/or the block-segment, these shares are attributed respectively to one of the seven mixed categories. The graphic differentiation of the mixed categories is shown by coloring and cross-hatching.
The entire heated area within a block and/or block segment area is the reference base for the proportional assignment of the individual heating types. The average heated area for living and work per block totals approx. 9,100 m2. The representation of the entire heated area in the block and/or in the block segment area is shown by means of a three-stage symbolic labeling. The average heated area of all blocks is approx. the median value of Level 2, or „5,000 to 15,000 m2“.