And while the intention of the parties in the deal may be straightforward, unfortunately the law is often not. Particularly tax law, which may dictate a transaction structure quite different from the terms of the letter of intent. The tax code provides many ways for real estate owners to defer or even avoid recognition of gain, and it's best to include tax advisors as early as possible before the parties' expectations get set.

An even bigger problem is that a letter of intent may very well be an enforceable contract, which requires only a writing, signed by the parties, containing the primary terms of the deal, such as the property and the price.

Several cases in the past decade have held enforceable very simple and informal letters of intent, because they meet the legal requirements for a contract.

But what about the other thirty or forty pages of a typical real estate purchase agreement, loan document, or lease? Courts will imply "customary terms" into the letter of intent to supply all of those missing pieces. That is, the judge will supply most of the terms of your inadvertent agreement based on an understanding of "customary terms", which will based upon conflicting expert testimony obfuscated by litigators.

To avoid this, lawyers routinely insert language into term sheets attempting to make it abundantly clear that the parties do not intend the term sheet to be a legally enforceable document (usually excepting confidentiality and exclusivity provisions).

In some cases, though, courts have found poorly worded "not enforceable" language unconvincing, and have implied obligations to negotiate in good faith or use best efforts to reach a deal, so the wording of the "not enforceable" provision is very important.

Bottom line: for important practical, tax and legal reasons, it is critical to involve experienced real estate counsel from the very beginning of the discussions of your deal.