First of all, I want to congratulate you for getting your offer accepted by the seller. Because any selling agent (agent that represents the buyer) these days work extra harder to get their buyers offers accepted. I am saying that because it is a seller's market now. Meaning there are a lot of buyers and not enough properties on the market for sale.
Anyways, your situation is quite simple, if your agent is experienced and are aware of this situation, he/she should have you sign a standard real estate form called the - Extension of Time and send it to the listing agent and seller to request for more time. That should be done days ahead of the contingencies due date and should not wait until the due date to allow time for the seller to have the form sign and send it back to you and your agent. I have done this for my buyers many times in many transactions due to various reasons. My personal experiences is 99% of the time sellers are willing to sign the form, as long as they feel you (the buyer) are sincere about purchasing their property.
As for you being concern about the listing agent giving you the notice to perform. It is unlikely that will happen because it is the listing agent and the seller who are unable to help the appraiser gain access to the property. It is also not uncommon that the tenant are not cooperative. Things should still work out eventually as long as all parties have the same goal.
Hope my answer is helpful to you and that you can work things out and move on with your purchase.
Without seeing the contract, generally speaking the appraiser has to be able to see the home. There is an appraisal contingency int he purchase contract. What I don't know is if you waived that contingency when you bought your home.
If you don't have an agent, speak to a real estate attorney to know your rights.
I believe a little patience may be your best move; providing the Seller with a notice to perform may just elevate the Seller's stress level to a point where it makes things worse.
Seek first to understand, and then be understood. Meaning, have your Agent find out the specific reason why the Appraiser has not been able to access the property and what the Seller is suggesting to remedy the issue ( I'm wondering if the tenants are on a mo.-to-mo. or a lease).
Once you find out what the issue is this Landlord/Tenant Guide may come in handy:
(Marked page 50-51 may be in play)
Your goal is to make this property your own and you probably do not want to re-start your search, nor do you be subject to an even higher purchase price on the next property (I assume your area is also a â€œSellerâ€™s Marketâ€ right now with prices escalating?).
Hope your realtor is constantly following up with the listing agent...and if that fails, to contact the broker.
It is the seller's and the listing agent's responsibility to provide access so that you can complete your own contingencies
If anything, your realtor you pursue issuing notice for seller to perform.
Since this has put your own schedules in jeopardy, you should also request an extension, and make sure you clearly state the reason for the extension.
I think it would be highly unlikely they would send you a Notice to Perform in this instance. That being said, you should still be proactive on this matter. First, verify with your lender that an appraiser has been assigned to the file and has attempted to make contact with the listing agent. If that has occurred, then have your agent contact the listing agent immediately for a status on the appraisal.
Best of luck!