Most sellers have done more for their home than they can prove. A furnace replaced six years ago, a re-roof with a transferable warranty, an appliance suite still inside its coverage window. All real work. Almost none of it survives into the transaction as anything more than a sentence.
Unevidenced improvements get discounted
When a buyer cannot verify a claim, they price the risk instead of the improvement. "Newer roof" invites a question rather than settling one: how new, by whom, under what warranty, and is any of it transferable? Each unanswered question is room for the buyer to negotiate down.
Attach a receipt, an installer name, a photo, and a warranty term to the same claim and it stops being a question. The improvement can be priced because it can be checked.
Documentation compounds
A single receipt is a data point. Several years of receipts, service dates, and warranty records form a maintenance narrative, and that narrative is what a careful buyer is really buying. It signals a home that was looked after, which is precisely the thing inspection reports cannot tell them.
Where the value actually shows up
Documentation tends to pay off in three places: fewer inspection-driven renegotiations, because surprises were disclosed up front; faster answers during due diligence, because the record already exists; and better positioning against comparable listings, because yours is the one that can substantiate its condition.
None of that requires a new appraisal method. It only requires that the work already done be findable at the moment someone asks.