Open Access Te Herenga Waka-Victoria University of Wellington
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House Conversions and Sharing for an Ageing Population in New Zealand

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posted on 2021-12-07, 13:57 authored by Yavari, Fatemeh

With the rise in the number of people aged 65+ in New Zealand, it seems increasingly important that there is a supply of appropriate housing so they can remain in their communities and ‘age in place’ for as long as possible.  Evidence from both literature and statistics showed a mismatch between current and projected household characteristics and the existing housing supply in New Zealand. Therefore, this research investigated the potential for converting existing dwellings to address the housing shortfall and ageing in place in New Zealand. The aim was to make the selected houses both smaller and more age-friendly, as a means of achieving ‘ageing in place’ in well designed, and easy to heat and maintain homes.  Two New Zealand housing types were investigated (villa and state house). Using the New Zealand Lifemark 3-star standard, both were redesigned with different degrees of shared space. Three designs were produced for each house, ranging from subdivision (conversion to two smaller units), to having some shared spaces such as a guest bedroom, to private en-suite bedsitting-rooms and all living spaces shared. Using a mixed methods approach, the schemes were evaluated by client and expert participants in three steps.  1. The aim of the questionnaire-based survey was to obtain comments on the conversions, particularly regarding the levels of sharing. Following the two pilot surveys and subsequent revisions, a web and paper-based questionnaire survey was undertaken by 441 respondents aged 55-85.  2. To assess the designs and specifically whether they incorporated appropriate housing standards for people aged 55+, they were evaluated by five built environment and ageing population experts.  3. To probe the reasons behind the survey results, two rounds of client focus groups of 17 participants aged 55+ were conducted.  What was clear from the results, and which aligns with other studies, was that a high proportion of older people would prefer to age in place, either in their existing house or in a more suitable dwelling within their community. However, the cost of house conversions was perceived as problematic, as people felt that they would not be in a position to afford to do this, even if they could sell or let the new unit they would not occupy. On the other hand, the significant benefits of upgrading a house for older people include reduced energy bills through effective design strategies, such as thermal insulation and double-glazed windows, and incorporation of future-proof design features such as the installation of assistive devices like stair lifts.  Generally, schemes with higher degrees of sharing were not attractive to many respondents and those aged 75-85 were more likely to dislike these than the younger age groups. However, both expert and client groups agreed the acceptability of sharing depends on people’s personal preferences, culture, and background. Findings from this research also show that having a spare multi-purpose room, a private deck and a good-sized dwelling with plenty of sunlight are features most people wanted.  This research suggests that people aged 55–85 have very specific housing needs when it comes to ageing in place. Therefore, to ensure their requirements are met and dwellings are usable, engaging potential users in the design process at an early stage is essential.


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Date of Award



Te Herenga Waka—Victoria University of Wellington

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Author Retains Copyright

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Degree Grantor

Te Herenga Waka—Victoria University of Wellington

Degree Level


Degree Name

Doctor of Philosophy

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Victoria University of Wellington Item Type

Awarded Doctoral Thesis



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Victoria University of Wellington School

School of Architecture


Vale, Brenda; Isaacs, Nigel