Dynamic Thermal Simulation

In order to capture more data for analysis, dynamic thermal simulation was considered for this study and will be briefly discussed below.

4.6.1 Thermal Modelling and Simulation Software

The software (DesignBuilder, 3.2.0 version) was considered for this study in order to carry out dynamic thermal modelling and simulation. The dynamic modelling and simulation software known as DesignBuilder (EnergyPlus) (US DOE, 2005) is created in the United States by the Department of Energy.

4.6.2 The Outdoor Weather Data Considered for Modelling and Simulation

The outdoor weather data files on hourly basis were considered for this study and cover the monitoring periods at the case studies (Bridport and Oxley Woods) and current Test Reference Year (TRY) which is the representative external weather data files for recent climatic conditions. The London Islington TRY (that is, the 2000s) was considered for

Bridport House and Stadthaus Housing in Hackney, London due to the two case studies’

proximity to London Islington while the St Albans TRY (that is, the 2000s) was used for Oxley Woods in Milton Keynes.

4.7 Summary

This chapter discussed the data protocol and techniques used for data collection that included post-occupancy survey, environmental monitoring, comfort survey and dynamic thermal simulation. The procedure and strategy employed help to conduct the surveys in a

68 way that did not interrupt everyday activities of the occupants. The field studies were more organised and well-planned from selection of the case studies to getting permission to access the case studies to conducting the surveys and gathering of data for analysis. The steps taken enhanced the quality of data gathered and greatly reduced disruption of the equipment used for physical measurements which in turn reduced errors that may occur during the recording and logging of data. This study was conducted in a logical way, thus improving the reliability of the results from the surveys.

The data protocol and collection techniques showed that post-occupancy survey helps to

assess the case studies’ performance with a great input from the survey participants while

environmental monitoring involves physical measurements of environmental parameters to understand the thermal environment with limited or no input from the occupants.

Comfort survey helps to understand that the occupants’ expectations are not static and

change from time to time while dynamic thermal simulation helps to capture more data that cannot be covered by other methods employed. The combination of different methods provided a wider range of data that can be analysed and compared during analysis. It also provided a better understanding to investigate the research propositions using various techniques to see similarities and differences between the results.

This chapter showed explained that a combination of the methods that require limited or no input from the occupants and the methods that required a great input from the participants are important when evaluating the building performance. The results will be discussed in Chapters 6 and 7. The next chapter considers the case studies selected for this study.

69

Chapter 5 Case Studies

5.1 Introduction

“The unique residential building Bridport House represents green urban architecture of the future. It marks the first time that cross-laminated timber (CLT) has been chosen in the UK for an entire multi-storey structure, including the ground floor, which is traditionally constructed from concrete (like in the case of Stadthaus housing). [...]. Using environmental materials (sustainable materials such as timber), we were able to meet the sustainability objectives and in the end real construction costs remained under budget”

- London Borough of Hackney (2011: In Rethink, Bridport House Factsheet, pp. 1-2).

This chapter describes the three housing developments considered for this study. The case studies are Bridport House, Oxley Woods and Stadthaus housing. All the buildings are modern housing developments built for residential purposes with timber; a lightweight material with low thermal mass. The three case studies are recipients of various low- energy rating or sustainability awards completed within the last decade and built for the working-class to middle-class from high density to low density dwellings. Two of the case studies are modern multi-storey blocks of apartments (Bridport and Stadthaus) and the third one (Oxley Woods) a housing development with ten different prototypes. They are located in South and Southeast of England; the regions considered to be prone to summertime overheating (Orme et al., 2003; Firth & Wright, 2008; Lowe & Oreszczyn, 2008; Rijal & Stevenson, 2010; Porritt, et al., 2012). The description of each housing development will be presented. The design and internal arrangement of the case studies will also be examined and some other features such as the area of the sites will be briefly highlighted.

The floor area of the internal spaces at the developments will be briefly discussed. At a later part of this study (Chapters 6 and 7); the relationship between the internal floor

spaces and occupants’ comfort will be examined. The materials used for construction of

each housing development will be discussed. Sources of the materials, composition and their thermal properties will be examined. The construction methods used, the period of

70 construction, personnel involved and technological innovations adopted for the buildings will be outlined.

The last section under each case study discusses environmental sustainability of the project. This is important as it helps to understand the environmental impact of the materials used, the energy saved for production and the ability of the materials to sequester carbon. Also, sustainability in terms of energy used to transport the materials from the factory to the site will be explained. The differences and similarities between the case studies selected will be briefly highlighted at the later part of this chapter. The next section focuses on the case studies investigated.