1920 house to renovate and modernize with environemental friendly solutions

We hage a 124 m2 house from 1920, located in Asker and we would like to renovate and/or extend it. The house has 2 floors. The first floor has been renovated in 2007 and is fine, apart from the entrance and the stairs. We need a bigger entrance and maybe move the stairs. The second floor needs total renovation. It has 4 bedrooms, 1 toilet and a small office. We thought about lifting a part of the roof and adding roof windows for more light. We also thought about building a modern extension on the side and to renovate the terrasse. The "bod" would also need to be checked. We are a modest family of 4 and are looking for environmental, not too costy solutions. We are open to offers and are looking to meet a good arkiteky/entrepreneur to help us in our project.