In many loft conversions the bathroom can be en-suite or accessible from a landing.
1930s semi detached house
Was: 3 bedroom and 1 bathroom.
Loft conversion: Hip to cable rear dormer.
Now: 4 bedrooms + 1 bedroom/office and 2 bathrooms.
Please see my reference page.
I was also invited back to convert the little used sunroom into a kitchen/breakfast room which is now used every day!