Car Garage

I am purchasing a commercial garage being built for auto enthusiasts. Garages of Texas. My shell is 25 wide, by 45 deep with a mezzanine. I am looking to have plans prepared for the city of Lakeway in Texas and they require a full set including MEP's. I am a GC so plan to build myself. I need to add a nice bathroom with shower to the lower level plus a wall of lower cabinets upstairs with a couple appliances built in. It will be an entertainment wall with a sink, undercounter refrigerator, warming drawer and microwave. Required a licensed architect for Lakeway approval. Shell is already wired for basic electrical, plumbing drain line, and has fire sprinklers.