Daylight dilemma

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Paari Vendhan

Design dilemmas

Hi

We are soon moving to an old house. It is west facing rectangular shape overall with old style windows, so rooms are dark in day time also. Thinking of opening up one room with full slide glass window, but also do not want to spend a bomb. How much typically would cost and please suggest any more/better/effective design solutions. I have attached  rough 3D illustrations here (1. current state, 2. current solution in mind). And here is the 3d view: https://skfb.ly/6vSDW

2018 01 19 13h13 26
2018 01 19 13h13 26 2018 01 19 13h13 07