By chance, I've just started reading
The Clerkenwell Tales by Peter Ackroyd, set in 1399. There's a short chapter called The Merchant's Tale which -- surprise, surprise! -- deals with a merchant, his wife and apprentice. There's not a lot there but if you can get a copy out of the library or cheaply second-hand, it might be worth a look.
More to the point, it describes the merchant -- a haberdasher -- going down to the shop and "he unlocked the wooden shutters and unfolded the counter" which instantly made me think of the Medieval Merchant's House in Southampton, which I should have remembered as soon as I first read your thread. It was built c1290, so a bit earlier than you want, but it's still indicative of how they'd have been living until the mid C14th.
The English Heritage page on it is rather underwhelming, but there's a bit
more about it on Wikipedia. EH guides are usually very good on giving background, but I can't recall if they have one for the house.
I should also have remembered the shop at the Weald and Downland Museum, which is mid C15th, so a bit later, but again indicative of what would have been around earlier
Medieval Shop from Horsham | Weald and Downland
I know these are structures, but I'm a great believer in considerng how buildings reflect what is going on in daily life eg is there only one large bedroom, or have smaller rooms been created? That not only informs the issue of sleeping arrangements, but also their social structures and ideas of privacy. Anyhow, the buildings are wonderful to see, so if it's possible, they're all good for a day out. Plus, the W&DM has a number of living history days throughout the year when some buildings are occupied by living heritage groups/enactors, who can be questioned closely about social issues.