Is it possible to get a cotingency in the purchase agreement when buying new construction?

[Daniella W.]

I have a client who wants to purchase a new construction home in San Diego BUT we need the purchase to be contingent upon the sale of his current home. When I asked the listing agent if they would agree to this, she said flat out "no". The builder is Lennar. 

Does anyone know any way around this? Has anyone had any success with this issue? The market here is very strong and I can understand why they do not want to agree to this contingency, however, I feel I owe it to my client to do my best to make it happen!

Any advice or ideas would be greatly appreciated!