How i can make maps less laggier?

i have some problemos XD with a new map the i am making its kinda big but it lags a LOT in some areas, can some one please help me to make it less lagier?

You could reduce the amount of textures used. You can reduce the size (for instance, 64x64 textures turn into 32x32). You could also reduce the maps size. Take out a few spawns. NZP can't handle that much seeing as it's Quake but these are a few tips.

For some reason changing the map's light level to -100 made my maps lag a bit less. Also if you have a lot of furniture or things you made in the map editor try replacing them with models instead.

Thanks :D

Also if you make the walls as thin as possible, I would say possibly a 2 or 4, it usually makes it less laggier.