It is possible for architectural designers to rely too much on technical details, specifications, and construction quality to overcome the challenges created by a design concept. A design concept can overwhelm the intended performance of roofs and walls that are expected to manage water and keep it out of a building’s interior. Where a roof slopes down toward or against a wall, the best flashing detail may simply not be up to the task of protecting the building from leaks. A roof configuration that includes numerous dormers and valleys, changing slopes and materials, and multiple levels can make drainage paths so convoluted or restricted that ice formations and leaks in snow country are almost inevitable. Roof design complexity also challenges effective ventilation of roof framing areas, especially in and around dormer and cathedral ceiling areas.
It’s interesting that popular features like dormers that mimic historic buildings can also bring problems like ice dams and leaks.
Avant-garde designs that tilt walls and rely on the wall materials to perform like roofs also risk performance shortcomings.
The best time to consider these possibilities and minimize risks is when the design is still in a formative stage.