The building is sports facilities located in England. The goal is to extend the existing building and better the internal layout to suit the changing needs of the community and to meet current legislation. This includes adding another level, a new roof, changing the floor plan where necessary and upgrading the walls for u-value.

Building regulations and other applicable legislation require careful consideration at an early stage.
The client brief and schedule of accommodation is as follows and all must be accommodated
within your proposals / reports:
• maintain the same number of changing facilities
• maintain the existing umpire facilities
• enlarge the clubroom and ancillary facilities i.e., kitchen, bar, server
• provide a new reception area
• ensure a security room and main office is provided
• provide a spectator viewing area
• additional visitor toilet facilities
• first aid and physio room
• additional storage for plant and hockey equipment
• additional office and conference facilities
• adapt the existing to become inclusive, including the addition of inclusive facilities
• improve the efficiency of the building
• promote sustainability in the development.
The building must be an exemplar low-energy building in which passive design strategies are utilized where possible, in order to minimize the energy demand of the building.
Available information:
- trench foundation
- existing walls are 140 block, 50 insulation, 100 block

I am counting on any advice regarding the improvement of the external walls, the construction of the additional level and the type of roof, regarding the floor plan, building regulations, etc.

I am attaching a photo of the existing building and floor plan.