We have a list of basic patterns for our new bathroom;
Privacy -when in shower and toilet, Shelter -from rain and wind; Flat; Paved; Light -natural in the day, electric at night; Hot water -shower tubs, basin; Ventilation -lots; Waste water used -subtropicals; Dry dressing place; View -stars, bush and gardens, of bath from kitchen window; Rocket bath; Clothes hanging space; Shaving & tooth brushing place; Hand washing between toilet and house and car park and house.....................
First we cleared the site then used fencing standards and wood ash to make sure things would fit and get an idea of hot things would feel.