Hilchos Maasei Hakarbanos 5:3

We know that offerings of the highest sanctity must be slaughtered in the north of the courtyard from Leviticus 1:11. Regarding burnt offerings, it says: “It shall be slaughtered on the north side of the altar.” Regarding sin offerings, verse 6:18 says: “In the place where you slaughter the burnt offering, there you shall slaughter the sin offering.” Just as the sin offering is an offering of the highest sanctity, so is the burnt offering. Regarding guilt offerings, verse 7:2 says: “In the place where you slaughter the burnt offering, there you shall slaughter the guilt offering.” A connection was made between communal peace offerings and sin offerings, as per verse 23:19: “You shall offer one male goat as a sin offering and two year-old sheep as a peace offering.” Accordingly, these are sacrifices of the highest sanctity like the sin offering, and are therefore slaughtered in the same place. The animals’ blood is received in the same place where they are slaughtered.

Hilchos Maasei Hakarbanos 5:4

We know that offerings of lesser sanctity may be slaughtered anywhere in the courtyard – even behind the Heichal (the “Sanctuary”) – from Leviticus 3:2. Regarding peace offerings, it says: “You shall slaughter it at the door of the Tent of Meeting.” This means that any direction is acceptable because no one direction was specified; this is also true of other offerings of lesser sanctity. If they were slaughtered inside the Heichal, they are valid, but if they were slaughtered on the roof of the Heichal they are not valid. This is because roofs are inherently unsuitable for slaughter, which must be done on the ground of the courtyard.