That painting I have from someone in my grandmother's family of a church with a tile roof in Norway, maybe Sarpsborg? Linked here so I don't lose it, a picture of a building at Borgarsyssel Museum in Sarpsborg. Sure looks like it.
And Sarpsborg i middelalderen has a picture, with these cutlines: "Portalen på Olavskapellet på Borgarsyssel muesum er en kopi fra Skjeberg kirke en av de to middelalderkirkene i Sarpsborg." [Portal of Olav's chapel in Borgarsyssel museum is a copy of Skjeberg church one of the two medieval churches in Sarpsborg.] Not much information, but something to go on. It's a two-page PDF file available on the Sarpsborg kommune [local government] website. Address: