An appraisal for a heloc will likely be based on the original purchase price plus any documented improvements. Banks don't like to give you credit based on unrecognized appreciation.
I thought comps were recent sales. ??? If it's other houses on the market, that's a crazy way to do it.
in our fairly recent experience 'comps' are COMPLETED (actually closed-can't be a pending sale) "recent" sales (recent as defined within a certain established time frame criteria).
when our former home sold it was right as the housing bubble burst in that area-when that home closed it was the only closing for over 60 days in that city, and the house was constantly being photographed by appraisers to use as a comp (BAD comp to use-b/c home values were falling by tens of thousands per week so ours was not a good comparison). where we live now it was challenging for our recent appraiser to find comps in close proximity to us-that's b/c no one in our neighborhood has sold in several years (newer homes/all custom built and largely very different from each other) so he had to do some kind of process where he found a physical home comparable to ours a distance away then calculate out and document how our physical location (for commute, school district, services....), land (acreage, views) would positively or negatively impact those comp sale prices.
one thing I found interesting is how 'current market trends' impacted the calculation-apparently the area the appraiser used for the comps on ours was going through a period of time where the 'norm' in sales was for the seller to pay for the buyer's closing costs, but it's not for our area. the appraiser therefore documented that while this was the trend and he would normally offset the value for it, in our case he was not.
so in our experience (and the experience of several neighbors who have either done a re-fi' or helo recently) it comes down to-
the VALUE of what the home could within reason-NET (after regional sales concessions) in a sale at the time of appraisal. what someone paid for their home is not a factor-WHAT THEY OWE on their mortgage (or any other debt that's secured by the home/land) becomes a factor AFTER the appraisal when the bank/lender is crunching the numbers to see if they will extend monies to be secured by the home based on the current appraised value of the home.
example-2 houses each purchased for $350,000 with current identical appraised values of $400,000 (owners with same income/credit scores/other debt)-
owner #1 owes $310,000 on their mortgage-bank/lender may or may not approve helo depending on stability of local housing market
owner #2 owns their home free and clear-bank/lender trips over itself to barrage the owner with offers for a helo (I only know this b/c we get 2 or more offers per week for preapproved/all fees waived helo's from our bank ever since we paid off our mortgage).