Though I've never seen the term before, I strongly suspect that it is a toponymic used to describe this particular, local "school" of late gothic architecture.

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Note added at 2003-05-21 19:47:26 (GMT)
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In addition to the familiar names commonly given for the basic \"styles\" of medieval architecture (eg., \"Romanesque\", \"Gothic\"), each of these also had regional variations : \"Burgundian Romanesque\", \"Picard Gothic\".
Tubize appears to be in the Belgian provence of Brabant, but it is just over the border from Hainaut, so the Late Gothic (and the 16th c. is indeed very late for Gothic) church there must have been built in the \"Hainaut\" style, the Belgian/French adjective for which is \"hainuyer.\"
If there were Gothic or Romanesque buildings indigenous to Southern Indiana (where I live) they would be characterised as being \"Hoosier Gothic/Romanesque\" --which is much more difficult to translate than is \"Hainuyer.\"
Leave it as is, or say : \"the church of Sainte-Renelde is a superb 16th century building in the style of the Hainaut region\" would be my recommendation.

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Note added at 2003-05-21 19:54:22 (GMT)
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sorry : \"...16th century *gothic* building, in the style of...\"

The point of the distinction being, apparently, that the church is not built in the Brabrantais (or whatever) style.