I bought a house with a deck, but it is not up to code like the seller told me.

It depends on your contract with the seller or inspector. Did you hire an inspector to inspect the house before you bought it? Did you waive inspection in your purchase contract? If so, then you probably do not have a good case against the seller for misrepresenting the condition of the deck. The "economic loss rule" would most likely bar a misrepresentation claim where your contract allocated the risk of loss. Recent cases including Jackowski v. Borchelt, 151 Wn. App. 1 (2009) and Cox v. O’Brien, 150 Wn. App. 24 (2009), held that fraud claims for the seller's failure to disclose that one property was in a landslide zone and another house had structural defects were barred where a reasonable inspection would have revealed the problems. By failing to conduct a reasonable inspection or waiving the inspection contingency, the buyers assumed the risk of any defects. In Alejandre v. Bull, 159 Wn.2d 674 (2007), the Washington Supreme Court held that a seller who failed to diclose a defective septic system could not be sued for fraud or misrepresentation, but only for contractual remedies. The economic loss rule would not prevent a breach of contract claim, a suit to rescind the purchase, or claims against an inspector if he/she failed to spot the code violation, but could make it difficult to sue the seller for fraud or misrepresentation unless those claims were reserved in your contract. The dollar amount in question would make this case appropriate for small claims court.