Daniel Fosas

Many competing airflow models are available to aid designers size windows for natural ventilation, but their complexity in terms of computation and the required expertise needed has limited their application in shelter design. Shelters house over 8 million people worldwide, and the prevalent inadequacy of indoor air quality exacerbates health risks. This study examines the use of simplified airflow models to guide the shelter design process to deliver adequate natural ventilation schemes and window dimensions. The classic Warren equations for natural ventilation are compared with airflow network models in Contam and EnergyPlus to contrast design outcomes from a practical perspective. Five natural ventilation mechanisms are tested across a representative single-zone shelter, based on those at Hitsats refugee camp (northern Ethiopia), using indoor CO2 concentrations as the key performance indicator. Results for opening sizes and ventilation layouts derived from Warren are in close agreement with those from airflow network models in Contam and EnergyPlus. Wind-driven scenarios feature the same window size for 99% of the time, while buoyancy-driven scenarios are for 94–97% of the time. These results prove that simplified modelling approaches would lead to the same design decisions as more complex models, making them as suitable and as reliable for the design of single-zone shelters.

The imperative for decarbonization demands the swift realization of net-zero buildings by 2050. Significant efforts have been directed at new buildings but, looking ahead, there is a need to shift towards whole-life management given buildings’ extensive lifetimes. With this objective in mind, this paper delves into scalable strategies for decarbonizing building stocks by conducting a systematic literature review concentrated on the in-use life cycle stage of buildings. Its scope is non-domestic building portfolios, a complex, under-researched stock that features dedicated teams overseeing their maintenance and operation - a management approach ideally placed to address sustainability challenges. Recent literature is analysed according to assessment of building portfolios, intervention types, and rollout mechanisms. This is then complemented with non-academic literature and governmental initiatives worldwide. Findings highlight challenges in understanding the performance of buildings in sufficient detail to inform effective retrofit planning and financing interventions. Fabric-first approaches, while desirable for their multiple benefits beyond reduced environmental impacts, do not necessarily arise as the most economically competitive measures. In contrast, just understanding and optimising energy use is reported to deliver 20% energy savings cost-effectively. Overall, findings highlight challenges and opportunities associated with proactive management of buildings alongside areas for future research.

As events like the 2003 European heatwave showed (where 14,000 people died in Paris alone), it is in the extremes of weather, not the mean climate, where much climate change risk lies. Communication with the public, or the testing of natural and human-made environments via simulation, has focused however on the mean situation. To many, a future 2 or even 4 °C rise in mean temperature will seem modest and hence fail to convey the scale of the issue, thereby creating a gap between reality and expectation. Here we use the idea of presenting an audience with a week-long time series of future local extreme weather as a way of bridging this gap. A week has both vernacular currency and covers the length of many heatwaves. We generate UK future weeks in 2030, 2050 and 2080 at a 5 km interval, thereby allowing interested parties to visualise for the first time likely future heatwaves in their locality. Future heatwaves of similar form as the 2003 Paris event are found, but with even higher temperatures, suggesting the likelihood of largescale mortality. We apply the approach to the conditions within a UK home under future heatwaves with return periods of 10–50 years. Conditions far beyond adaptive comfort limits are found. Weather files containing the extreme weeks for 11,326 locations have been prepared and are made available. These will be of use to those trying to explain the likely impacts of climate change, governments setting resilience policy and those using computer modelling.

In most industrialized countries, the buildings sector is the largest contributor to energy consumption and associated carbon emissions. These emissions can be reduced by a combination of energy efficiency and the use of building integrated renewables. Additionally, either singularly or as a group, buildings can provide energy network services by timing their use and production of energy. Such grid-aware or grid-responsive buildings have been termed Active Buildings. The recent UK Government investment of £36m in the Active Building Centre is a demonstration that such buildings are of considerable interest. One problem with the concept, however, is that there is no clear definition of Active Buildings, nor a building code to design or research against. Here we develop and test an initial novel code, called ABCode1. It is based on the need to encourage: (i) the minimisation of energy consumption; (ii) building-integrated generation; (iii) the provision of grid services; and (iv) the minimisation of embodied carbon. For grid services, we find that a lack of a precise, quantifiable measure, or definition, of such services means that for the time being, theoretical hours of autonomy of the building is the most reasonable proxy for these services within such a code.

Given climate change predictions of a warmer world, there is growing concern that insulation-led improvements in building fabric aimed at reducing carbon emissions will exacerbate overheating. If true, this would seriously affect building regulations all over the world which have moved towards increased insulation regimes. Despite extensive research, the literature has failed to resolve the controversy of insulation performance, primarily due to varied scope and limited comparability of results. We approach this problem through carefully constructed pairwise comparisons designed to isolate the effect of insulation on overheating. We encompass the complete range of relevant variables: latitude, climate, insulation, thermal mass, glazing ratio, shading, occupancy, infiltration, ventilation, orientation, and thermal comfort models — creating 576,000 building variants. Data mining techniques are implemented in a novel framework to analyse this large dataset. To provide confidence, the modelling was validated against data collected from well-insulated dwellings. Our results demonstrate that all parameters have a significant impact on overheating risk. Although insulation is seen to both decrease and increase overheating, depending on the influence of other parameters, parameter ranking shows that insulation only accounts for up to 5% of overall overheating response. Indeed, in cases that are not already overheating through poor design, there is a strong overall tendency for increased insulation to reduce overheating. These results suggest that, in cases with acceptable overheating levels (below 3.7%), the use of improved insulation levels as part of a national climate change mitigation policy is not only sensible, but also helps deliver better indoor thermal environments.