The Mishnah (Middos 2:1) says that the Har Habayis had the majority of the empty space in the south, the second biggest in the east, third in the north, and the least in the south. most Meforshim explain that this means the empty space between the Azarah walls and the walls of Har Habayis, and this is how I made my calculations of where the original Har Habayis was. However, there is another opinion, (R' Yehosef Ashkenazi, brought by the Meleches Shlomo, this opinion is also brought by Maharam Kazis) that it means the space between the Har Habayis walls and the walls of the Azarah and the Ezras Nashim.
In the sefer ביאורים על ציורי הרמב"ם למסכת מדות (page י"ב) Yosef Meijer says, that the Rambam also agrees with this opinion, because in his drawing on this Mishnah, he seems to draw like that. However, in Hilchos Beis Habechirah (5:6), The Rambam says clearly that it is talking about the space between the Azarah and the walls of Har Habayis, not the Ezras Nashim. Also, in his explanation of this Mishnah, he says "They said that the Azarah was not in the center of the Har Habayis... and I will now draw this, and I will draw the Cheil and the Soreg and the Ezras Nashim, that are mentioned in this Perek, so that it will all be one picture, and I won't need to make a lot of pictures." It seems from this that just to explain this Mishnah, you don't need to draw the Ezras Nashim, Just the Azarah.
However, even though the Rambam doesn't hold that the Ezras Nashim is included, other Meforshim do, so I made some calculations to figure out the exact location of the original Har Habayis according to them. The numbers I came to are: 275 amos in the south, 95 in the east, 90 in the north, and 78 in the west. (When I made these calculations, I thought that the Rambam also holds like that*, so I made the Beis Hamikdash according to the Rambam, so I made the Even Hashisiyah all the way in the west of the Kodesh Hakodoshim. According to the opinions that the Even Hashisiyah was in the center of the Kodesh Hakodoshim, it would be 270 amos in the south, 100 in the east, 95 in the north, and 73 in the west.)
(*I also made the map then, so all the details are according to the Rambam.)
I have added a new video of the Lishkos on the northern side of the first Beis Hamikdash..
My name is Mendel Lewis.
Hashem said to Yechezkel, "Its reading in the Torah is as great as its building. Go and say it to them, and they will occupy themselves to read the form of it in the Torah. And in reward for its reading, that they occupy themselves to read about it, I count it for them as if they were occupied with the building of it. (Tanchuma tzav 14)