1 - Use a pencil to draw out the existing layout. This doesn’t have to be perfect. Include locations for windows, radiators, closets, doors, built-ins, fireplaces, etc.

2. Using a tape measure, measure each wall in the room from corner to corner. This is the overall length of each wall.

3. Once you have the overall length of each wall, measure each wall in detail. Start in one corner, going around the perimeter of the room. Measure the corner to the outside of the window or door casing to the opposite outside casing. Measure wall expanses. Windows, radiators, closets, doors, built-ins, fireplaces, etc. Everything should be measured from the outside edge to the outside edge. 

4. Calculate details measurements for each wall and compare them to the overall length of each wall.

5. Make notes on your layout about any detail in the room, such as ceiling height, power outlet locations, sconce locations, ceiling light locations, floor changes, etc.

6. Please include measurements from the floor to the bottom of the window casing, as well as the heights of windows and doors. Elevations are helpful, but not required, you can use numbering on the plan to specify details separately.

NB! I take your measurements as provided, I can't be responsible for incorrect measurements. But if I see that something important is missing, I will ask you to send me additional information.