I'd be happy to have a look at your project. In the range of 1-2 hours of work, I can come up with some ideas, roughly check the feasibility, and make a first high-level project plan. This is free from costs.
For sure you also are interested in the costs of your project. Maybe you have a fixed budget and want to know what can be realized with this cost ceiling?
To estimate the exact costs in advance of a construction project is almost impossible. There are so many dependencies, such as chosen materials, the unforeseen, change requests after project start, and so on.
However - by means of a reliable analysis - the scope of the costs can roughly be estimated already at this stage.
Steps 1. - 4. are free from costs and non binding for both parties.