More efficient way of creating grid?

So I'm creating a game which utilizes a placement system I made, and I would like to create a grid on the client to outline where the user can place things. The following code does just that, but I would like to make it more efficient because I feel as though theres a lot of redundant math (and code, namely lines 12 and 13).

You might notice that instead of creating longer lines which are the length of the plot, I opted to create many smaller lines which are the length of each tile; this is intentional and essential for other parts of the system to function properly.

Here's a picture of what the grid looks like http://gyazo.com/2b9600...

function Module.CreateGrid(GridSize)
	if game:GetService("RunService"):IsClient() then
		local Plot = Module.GetPlot(game.Players.LocalPlayer)
		if Plot then
			local Grid = Instance.new("Folder")
			for x = Plot.Size.X / -2, Plot.Size.X / 2 - GridSize, GridSize do
				for z = Plot.Size.Z / -2, Plot.Size.Z / 2 - GridSize, GridSize do
					CreatePart("Square", Grid, GridSize, CFrame.new(x + GridSize / 2, 0.1, z + GridSize / 2) * Plot.CFrame, CFrame.Angles(0, 0, 0))
					CreatePart("Line", Grid, GridSize, CFrame.new(x, 0.1, z + GridSize / 2) * Plot.CFrame, CFrame.Angles(0, math.rad(90), 0))
					CreatePart("Line", Grid, GridSize, CFrame.new(x + GridSize / 2, 0.1, z) * Plot.CFrame, CFrame.Angles(0, 0, 0))
				end
				CreatePart("Line", Grid, GridSize, CFrame.new(Plot.Size.X / 2, 0.1, x + GridSize / 2) * Plot.CFrame, CFrame.Angles(0, math.rad(90), 0))
				CreatePart("Line", Grid, GridSize, CFrame.new(x + GridSize / 2, 0.1, Plot.Size.Z / 2) * Plot.CFrame, CFrame.Angles(0, 0, 0))
			end
			Grid.Name = "Grid"
			Grid.Parent = Plot
		end
	end
end

function CreatePart(Type, Grid, GridSize, Position, LookAt)
	local Part = Instance.new("Part")
	Part.Size = Vector3.new(GridSize, 0.1, (Type == "Line") and 0.25 or GridSize)
	Part.CFrame = Position * LookAt
	Part.BrickColor = (Type == "Line") and BrickColor.White() or BrickColor.Red()
	Part.Material = Enum.Material.Neon
	Part.Transparency = 0.75
	Part.CanCollide = false
	Part.Anchored = true
	Part.Name = Type
	Part.Parent = Grid
end