I am a homeowner with a basement suite in my home. In June I decided to rent it out. I found tenants that wanted to move in September 1. They signed a one year lease agreement. Recently we have learned that my husband will be losing his job. We will not be able to afford the mortgage payments on the home without his job. We will have to sell the house. I would like to sell it for as much as possible and I feel that it would be best to sell it without tenants living in the basement. That way it is easier to show the house to potential buyers and if a purchaser wants to use the suite for their family it is available to them. The lease was to start September 1 and I notified my tenant on July 16. I told them the situation and that I would return their deposit plus interest.
I understand that I could be sued for breach of contract. I am wondering how much money I can be sued for.

well first what does the lease allow or state for a party that is in breech ?

Also even with a renter, you can not make the mortgage payments ?
( entire other issue)

but they could try ( does not mean court will grant)
Cost of increased rent on a similar apartment. So if they find one that costs lets say 200 more than yours , if yours was a real deal. Then the 200 a month times the months in lease could be asked for.
If they have touble finding a place , the extra moving and storage costs and temp living expenses.

You may ask them to allow you to buy out the lease, esp since they have not moved in yet, I would start with perhaps a sum equal to 3 months rent to pay them to cancell the lease with you.

And I will address selling the house, you know what has happened to the real estate market these last couple of years, homes are worth from 25 to 50 percent of what they were 3 years ago. You may want to do some fast comparisons and get a current value on that home. Since a renter paying rent may help more than you realise if the home can not be sold for more than the loan value

It states that: "it is agreed that the Landlord will have the same remedies as in the case of nonpayment of rent in the event of a breach of performance by the Tenant of any of the terms and conditions of the agreement" There isn't anything with regard to the Landlord being in breach. There is nothing with regard to ending the lease before the lease even starts.

At this time the people who were going to rent my place have about 6 weeks to find an alternative place to live. I've looked at the local listings and there are probably 250 similar places available in this area. Most of the places charge less rent than I was going to charge. It seems like it wouldn't be difficult to find another place to live. If the tenants are not motivated to look for a place but there are lots of places available and they have 6 weeks to find a place what will the courts say?

Sorry, you keep saying before it starts, it has "started" once it was signed it became a legal document, they just have not acted on it and moved in at this time.

What will the courts say? Who knows some judges are more pro landlord, some are more pro tenant. And what money you offer them to end the lease will make some difference, if they refuse it, and it was a fair offer, the court will most likely look more kindly on it.

And of course the sooner you give them legal notice of your intent not to rent will matter also.

One thing does come to mind, how is the home zoned, it is zoned for multi family or single family. You can not legally even rent it out if it is merely zoned single family.