I think it's time for a functor

BuildingBlocks.fs

    type BuildingBlocks = {
            beam: BuildingBlock
            wall: BuildingBlock
            roof: BuildingBlock
            floor: BuildingBlock
            ground: BuildingBlock
            outsideFloor: BuildingBlock
            flatBeam: BuildingBlock
            pilar: BuildingBlock
            blackPilar: BuildingBlock
        } with
        static member unit = 
            let beamScale = {x=0.060M;y = 0.060M;z = 0.050M} |> SV
            {
                beam = (BuildingBlock.unit ShinyStuff) * beamScale
                wall = (BuildingBlock.unit Brick)* (S 5.000M)
                roof = (BuildingBlock.unit ShinyStuff) * (S 0.400M)
                floor = (BuildingBlock.unit Floor) * (S 0.050M)
                outsideFloor = (BuildingBlock.unit ShinyStuff) * (S 0.070M)
                ground = (BuildingBlock.unit Ground) * (S 0.050M)
                flatBeam = (BuildingBlock.unit Black) * beamScale * (SZ 0.001M)
                pilar = (BuildingBlock.unit ShinyStuff) * (S 0.075M) 
                blackPilar = (BuildingBlock.unit Black) * (S 0.075M) 
            }
        static member (*) (left, right) = 
            {
                beam = left.beam * right
                wall = left.wall * right
                roof = left.roof * right
                floor = left.floor * right
                outsideFloor = left.outsideFloor * right
                ground = left.ground * right
                flatBeam = left.flatBeam * right
                pilar = left.pilar * right
                blackPilar = left.blackPilar * right
            }
    and BuildingBlock = {size: Vector3D;material: Material} with
        static member unit material:BuildingBlock = {size = Vector3D.unit;material=material}
        member x.with_a_width_of width = CubeGeometry ({x.size with x = width},x.material)
        member x.with_a_height_of height = CubeGeometry ({x.size with y = height},x.material)
        member x.with_a_depth_of depth = CubeGeometry ({x.size with z = depth},x.material)
        member x.with_a_width_and_depth_of width depth= CubeGeometry ({x.size with x = width;z=depth},x.material)
        member x.with_a_width_and_height_of width height= CubeGeometry ({x.size with x = width;y=height},x.material)
        member x.with_a_height_and_depth_of height depth= CubeGeometry ({x.size with y = height;z=depth},x.material)
        static member (*)(left:BuildingBlock,right:Scale):BuildingBlock = 
            {left with size = left.size * right}