Measure your own space. Simple steps - Big savings!

Gather a detailed measuring tape (preferably a laser measure for accuracy and ease), graph paper for sketching, a sharp pencil for clear lines, and a clipboard or digital tablet to manage your notes and sketches. A digital camera or smartphone can be handy for capturing details to reference later. 

Before measuring, draw a rough sketch of each floor's layout. This doesn't need to be to scale but should include all rooms and major features (like staircases). Use this sketch to note measurements as you go, which helps in keeping track of what's been measured and what hasn't. Before measuring, note to use metric units.

Begin your measurement process from the outside. Measure the length of all external walls to get the total footprint of the building. This step provides a frame of reference for internal measurements and helps in identifying any potential discrepancies between the interior and exterior. 

Measure the length of each internal wall, room dimensions, doorways, and note the location of internal structural elements. Pay attention to the layout's flow, and measure spaces in a logical order to ensure no area is overlooked. 

Document the height of each room from floor to ceiling at several points to account for any variances in floor or ceiling levels. Also, measure the heights of doors and windows from the floor to understand the space's vertical elements. 

Measure the height and width of each window and door opening, including the frame. Note the distance of each opening from the floor and from the nearest corner of the room to accurately place them in your drawings. 

Measure the dimensions of any built-in furniture, such as kitchen cabinets, shelves, or fireplaces. Include these in your sketches with accurate dimensions and positions, as they are critical for space planning and interior design. 

Mistakes in measuring can lead to significant issues in the design process. Take the time to double-check each measurement, especially for critical elements like structural walls and openings. Confirming your measurements can save time and resources in the long run. 

As you complete each measurement, update your initial sketch to reflect accurate dimensions and notes. This updated sketch will serve as the basis for creating more detailed and scaled architectural drawings. It's also useful for identifying any potential discrepancies or measurement errors early in the process.