**1. History of Semi-Detached Houses in the United Kingdom:** – Semi-detached houses originated as a solution to housing issues for the rural and urban working classes in the 19th century. – Model designs for estate villages and double cottages gained popularity for cost-saving and comfort reasons. – Philanthropic societies and building societies played a role in assisting artisans and laborers in homeownership. – Model villages like Port Sunlight and Bournville were significant developments that inspired the Garden City movement. – The late 19th and early 20th centuries saw the implementation of standards and regulations for semi-detached houses, including water piping, heating systems, and accommodations for returning soldiers. **2. Housing Developments Outside the United Kingdom and Ireland:** – Semi-detached houses symbolize suburbanization in the UK and Ireland, while in places like Toronto, they are known as duplexes. – In the US, semi-detached houses are referred to as duplexes, twins, or double-blocks in different regions. – Philadelphia, Pennsylvania, is known for its popularity of semi-detached houses. – In Australia, semi-detached houses are called duplexes, with variations in ownership structures and popularity across different regions. **3. Semi-Detached Houses in Australia:** – Semi-detached houses, known as duplexes, had a brief popularity in Sydney in the early 20th century before modern detached housing replaced them. – Edwardian-era semis can still be found in places like Dubbo, New South Wales. – Ownership structures and architectural trends differ between semi-detached houses and townhouses in Australia. **4. Semi-Detached Houses in Canada:** – Semi-detached houses were a suitable option for narrow lots in downtown Toronto, with post-war periods seeing continued construction of such homes. – Toronto had a significant number of semis, with red-brick semis being common in downtown areas and older suburbs. – Various styles of semis were built in neighborhoods like The Annex and Cabbagetown. **5. Cultural References Associated with Semi-Detached Houses:** – Various cultural references in music and literature highlight semi-detached houses. – Songs like ‘Semi-Detached, Suburban Mr. James’ and ‘My Pink Half of The Drainpipe’ satirize aspects of neighborly relations. – Albums like ‘Semi-Detached Mock Tudor’ and songs like ‘Wisemen’ reference semi-detached houses in their titles and lyrics.