Create a flat vector, illustrative-style lettermark logo design for an architectural exhibition named 'Shelter', featuring the initials 'S' and 'H' intertwined in a sleek, modern font. The construction of the letters mimics building elements, with a minimalistic outline of a roof incorporated above the 'S'. Utilize warm neutrals and soft greens to emphasize connection with nature and comfort against a white background. Do not show any realistic photo detail shading.