[2006] EWHC 814 (TCC), 20 March 2006. M engaged R to carry out building works. After disputes arose in relation to quality of work and valuations, R referred its claim to adjudication. M had by then moved house, although he had not changed his business address. Notice of adjudication was served at M's previous home address. During the course of the adjudication, various letters were sent to M, and were all returned undelivered. The adjudicator made an award in R's favour. R commenced proceedings for enforcement; the court documents were served both at M's previous address and the address of his estranged wife. M did not respond, and judgment was given in favour of R. Over three years later, M applied to have judgment set aside, on the basis that he had been unaware of the litigation until two months previously. "Held": the Housing Grants, Construction and Regeneration Act 1996 s115 states that if a document is addressed and sent by post to the addressee's last known principal residence then it shall be treated as effectively served. In this case, there was a serious factual issue as to whether R had had available during the adjudication a ready means of contacting M (at his business address) which it chose neither to use nor to communicate to the adjudicator. A defence was therefore available to M which had a real prospect of success. The default judgment was therefore set aside.