On occassion I take a look at what is advertized as land, and at some of the forums where moving to a homestead is a regular topic. What I have noticed is the preocupation with building yet more houses, rather than finding areable land with functional even if barely adequite house and outbuildings. Building from scratch, including services is massively expensive and on limited financial and labour resources has to be to the detriment of the actual acquistion of the equipment and skills to grow food.
From a pragmatic perspective, adequete housing on a homestead where self-sufficiency is the goal; needs to be seen as the space where domestic work only, is done. This means that a far greater emphasis needs to be put on work space and storage space. A year or two worth of everything you need takes up a good deal of space, so does the equipment and workspace to produce and process everything, and the space needed to maintain the buidings, equipment, fences etc.
A years worth of animal feed, even if it is only for a few chickens and the bedding and the scratch and the tools to care for it all also takes up space. I find that keeping all this stuff out of the house is a huge labour and money saving effort. Most of this stuff does not need to be in heated space, but it does need to be out of the weather. Some out of the house heated work space also needs to be considered.
On the homestead/farm the largest issue often becomes keeping the dirt, parings, tools, etc out of the house in the first place.