This is the 10030th most frequent Russian word.
архитектурным
Architectural.
The word 'архитектурным' is used as an adjective modifying 'решениям' (solutions), indicating solutions pertaining to architecture.
Современным городам нужно уделять больше внимания архитектурным решениям.
Modern cities need to pay more attention to architectural solutions.
Here, 'архитектурным' is used as an adjective modifying 'стилем' (style), describing style in terms of architecture.
Этот парк отличается уникальным архитектурным стилем.
This park is distinguished by its unique architectural style.
In this sentence, 'архитектурным' modifies 'проектам' (projects), indicating that the projects are related to architecture.