Climate change projections estimate a rise of approximately 3 °C by the 2080‘s for most of the UK (under a medium emissions scenario at 50% probability level, 1961-1990 baseline). Warming is of particular concern for urban areas due to the issues of urban densification and the Urban Heat Island (UHI) effect. To combat warming, one adaptation strategy that has been suggested for urban areas is increasing the proportion of greenspace, such as parks, gardens, street tree plantings, and green roofs. While a number of studies have investigated the cooling effect of greenspace in terms of park size, proximity to a park, or area covered by tree canopy, little is yet known about the specific types of greenspace that contribute to its cooling effectiveness and how this relates to building energy demand. This thesis employs an interdisciplinary approach to model fine-scale changes to greenspace for a temperate northern UK city, linking the resulting microclimate changes to building energy consumption in commercial buildings. Using the urban microclimate model ENVI-met, two study areas (one urban one suburban) were modelled with seven different greenspace scenarios (a base case representing current field conditions, +5% new trees, +5% mature trees, +5% hedges, addition of a green roof on the largest building, changing all current greenspace to grass only, and changing all current greenspace to asphalt only) for a summer day in July 2010. The models were calibrated based on measured air temperature data and then analysed for microclimate changes due to each greenspace scenario. Both the modelled and measured microclimate data were then used to inform a series of building energy models using IES-VE 2012 for three commercial building types, estimating summer cooling and winter heating trade-offs due to greenspace effects. For the most effective scenario of adding 5% mature trees to the urban case study, the microclimate modelling estimates a maximum hourly air temperature reduction of nearly 0.7 °C at 5 pm and surface temperature reductions up to 1.7 °C at 3 pm. In the suburban case study, a 5% increase in mature deciduous trees can reduce mean hourly surface temperatures by 1 °C between 10 am and 5 pm, while the worst case scenario of replacing all current vegetation (20% of the study area) with asphalt results in increased air temperature of 3.2 °C at mid-day. The building energy modelling estimates a reduction of 2.7% in July chiller energy due to the combination of reduced UHI peak hours and eight additional trees (four on the north side and four on the south side) of a three-storey shallow plan building. These energy savings increase to 4.8% under a three-day period of peak UHI conditions. While winter boiler energy usage shows large reductions for a building in an urban location with a low proportion of greenspace (as compared to a suburban location), this benefit is marginal when analysed in terms of carbon trade-offs between summer cooling and winter heating requirements.

Urban greenspace has the potential to bring a lot of positive effects to the urban environment. Better health for its residents, increased biodiversity as well as helping the city adapt to the changing climate, to name a few examples. At the same time, the current planning paradigm in Sweden values the creation of dense urban environments. This, coupled with the current housing shortage, creates a situation where urban greenspace is being put under a lot of pressure and on the risk of being exploited in densification processes. This thesis has explored how urban greenspace is valued, as well as which strategies are being employed, in comprehensive municipal planning documents. Through the use of a documentary content analysis, comprehensive planning documents from three Swedish municipalities have been analyzed: Umeå, Uppsala and Helsingborg. The results shows that the analyzed municipalities have a fairly balanced valuation of its urban greenspace in their comprehensive planning documents. No one aspect of the sustainable development is given a significantly higher value compared to the other. At the same time, different patterns emerges when looking at themes underlying the different aspects of the sustainable development, with themes such as recreation being discussed to a higher degree in comprehensive planning documents from Umeå and Uppsala, compared to Helsingborg. The strategies employed by the studied municipalities are also quite similar, although the details vary. All three municipalities are vague in describing their strategies for urban greenspace, but Umeå and Helsingborg goes further with working with quantifiable goals, compared to Uppsala.

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