1.     Make sure you have a sturdy and decent length tape measure. This simply makes life easier and means you can measure quickly. 
2.     Have a paper and pen to hand for notes and to quickly sketch out the outline of your room. All you need is the general shape, no need for accuracy as long as it makes sense to you. 
3.     Mark window and door locations. 
4.     Start by measuring the width at the longest point of the room, the same with the depth and then the height. 
5.     Then take at least the same measurements at around 5 points across the room. This helps with accuracy, as most rooms are nor 100% even. 6.     Next measure all large elements such as alcoves and other nooks. Do this by following the same principle as above (width, depth and height). Note these measurements in the correct locations on your room outline. 
7.     Measure all the windows and doors. You want to know the width and height of the opening and then also the height of the window base from the floor.  Again mark this on the outline. 
8.     Make notes of all utility and socket locations i.e. radiators, sockets, aerial points. To measure their exact location, measure from the nearest fixed point (i.e. edge of the wall in a corner) to the middle of the fixture. This is particularly useful for radiator location. 

 Tips
-       When measuring the height of your room, make sure you allow for picture rail and cornice height. This is relevant for walls where you are wanting to feature wither freestanding or built in units such as shelving that require to sit within these parameters. Make notes where relevant. 
-       Doorway measurements are pivotal for planning furniture as well as the layout design, it’s all well and good picking great furniture but what if the space to get it in to the room is limited?! All these details help. 
-       Not location of any architectural features that are relevant or limit design decisions. 
-       Clear detail is key!