They are your roof trimming bodies.
You can turn them off in the VEIW menu > On Screen View Options > Trimming Bodies.
They won't print or render if you don't turn them off.
Barry.
One of the forum moderators.
Versions 6.5 to 27
i7-10700 @ 2.9Ghz, 32GB ram, GeForce RTX 2060 (6GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11