There is a growing concern for the consequences on climate change due to the increased concentration of greenhouse gases in the atmosphere. Integration of renewable energy technologies such as photovoltaic arrays and small wind turbines into buildings can alleviate the reliance on fossil fuelled energy supply.

The UK Government has set the target of reducing CO2 emissions by 60% by 2050. Energy used by buildings is presently responsible for around half of C02 emissions in the UK. There are many established methods for reducing such emissions from building operation but these opportunities are not being seized to their full potential. One of these methods is the use of Alternative Energy Technologies (AETs) integrated into the built environment. Engineering consultants have a key role in the design of buildings, their energy consumption and the consideration of AETs. The objectives of this thesis are to explore the process of delivery of AETs in building projects, the key factors that influence the viability of these technologies and the capability of engineering consultants to increase their rate of uptake. While there are many published lists of incentives and restrictions to using these technologies, there are few reports of their impact in practical contexts. Project involvement provided evidence of significant variations in the drivers and barriers to using AETs, the design team perceptions and the approaches used for assessments. These insights were investigated in detail through participative research techniques. Initial focus groups led to the development of a structured interview programme administered in 2 phases. The first phase of interviews investigated the experiences of 41 participants representing a range of building project stakeholders. The second phase of interviews looks more closely at 24 relevant projects from the perspective of the engineering consultant, investigating the decision-making approaches used and the influence of factors throughout the design process in more detail. As a result a hierarchy of the importance of specific drivers and barriers to using AETs in building projects was established. It was found that there is a large amount of variation in their importance between projects. Despite this variation the emphasis for assessment methods is on financial terms, largely ignoring more qualitative concerns. This lack of suitable assessment methodologies along with a lack of education, motivation and case study information in the building industry are restricting the use of AETs in UK building projects. It is proposed that to address this, engineering consultants need to be better informed and need to develop and embrace more holistic technology assessment methods that account for qualitative and quantitative considerations.