Can I be sued for unforeseen construction delays

You haven't provided sufficient information to answer this question. It would depend on the contract and the nature of the delays.

Disclaimer: This answer is provided as a public service and as a general response to a general question, it is not meant, and should not be relied upon as specific legal advice, nor does it create an attorney-client relationship.

I agree with Mr. Swanson. The starting point for the answer to your question will be the contract itself. Assuming the contract provides for the usual exceptions to timely completion of construction (e.g., acts of God, etc.), then the question becomes, What were the "unforeseen" causes of the delays? (Virginia law may not define "unforeseen" in the same way that you do.) There are often trade organizations that provide advice to contractors, so you may wish to see if you can find one in Virginia. Alternatively, I recommend that you contact your local state or county bar association for a referral to an attorney who may be able to assist you.