urbanLab Magazin 2021 - Transformation

When examining the results of the three options compared against the baseline, it
was clear that the most optimal scenario (termed Option 2 above) performed best
and had the potential to harness the most ecological quality in comparison to all
other options. However, the Selected Scenario remained the Preferred Planning
Scenario due to requirements beyond the climate analysis performed. Based on
a follow-up interview with the private property developer, these factors included
requirements related to permitting regulations, property ownership and conflicts
due to spatial limitations. The private property developer lastly indicated that, while
the primary solution would remain the Preferred Planning Scenario, dependent on
the requirements expressed by the city agencies responsible for planning approval,
Options 1 and 2 remained viable options that would be detailed in the upcoming
detailed design stages.
3.6 MODULE MICROCLIMATE AND HEAT
By reducing the quantity of sealed surfaces and replacing them with permeable
pavement (e.g. porous pavements, grass gravel, etc.) and a variety of green areas
(e.g. lawn, meadows, planted areas for recreation) instead of leaving the parking
lot in its given condition, there is an overall improvement to the microclimate parameters
analysed. Firstly, a Solar Irradiation analysis resulted, due to the placement
of the new building and the placement of trees, in a 29% reduction of solar
irradiation when measured at ground level (824.79 Wh/m2/day per annum versus
588.14 Wh/m2/da per annum). The existing condition receives more Sun Hours
(7.03 hours per day averaged over a year) compared to the proposed condition
(4.43 hours per day averaged over a year); however, this also results in increased
temperatures due to both a higher solar irradiation and sun hour amount. A Wind
Comfort analysis showed that there was only a minimal area of the site that had
the potential to be impacted by reduced wind comfort levels, defined typically as
above 5 meters per second (1.6% of the year above 5 m/s in the planning scenario,
3.01 % in the existing baseline condition). While the percentile difference via
the analysis was minimal, the visual comparison showed that, with the addition of
tree volume and the building mass, wind comfort could be optimised beyond the
already optimal state (e.g. the site does not suffer from wind comfort issue problems
generally). With the reduction or shift of paved surfaces to semi-paved or
vegetated areas, the average Albedo Factor increases by 0.1 / square meters; the
increased reflectance reduces heat retainment especially during the summer. The
Thermal Comfort indicator, based on the UTCI system simulating the average thermal
comfort of a site over a period of a year based on a 9-26° C comfort range,
indicates an improvement of 1.5% (48.7% of all days in the Planning scenario are
considered to be within the optimal comfort range, 47.2% in the existing Baseline).
3.7 MODULE ECONOMICS
For this project, only a preliminary Investment Cost indicator was analysed. For
the investment cost analysis, a cost range between approx. 393,300 (min.) € up to
740,800 € (max.) can be expected, equivalent to approx. 26-49 € per square meter
for the ca. 1.5 ha planning area. Prime contributors to the variability in costs are a result
of the selection of green roofs and green facades/walls as the result of selecting
these blue-gree elements account for approx. 69% (min.) to approx. 73% (max.) of
the total costs. By selecting a green roof with higher retention capacity or increased
soil depth, or the type of green façade (e.g. soil or system based) will have resultant
higher investment cost applications. In future design stages, an assessment of the
Maintenance Costs and Potential Savings can be considered to understand operational
costs or savings.
28 REGENERATIVE DESIGN