Having said that, my feeling is that it is better to have building permits than not.
Here are some of things to be aware of:
- The Costa Rican environmental institution, MINAE, is quite powerful and now requires property owners to obtain concessions where they intend to obtain water from springs or rivers rather than from the Costa Rican water authority (AyA).
- You make sure your property is properly registered. This is called the Plan Catastro. It will need stamping by different public institutions.
- You get some plans of your house drawn up to enable it to be valued by Costa Rica's institute of architects and engineers (CFIA in Spanish). The CFIA's fee is small, maybe 0.5% or less.
- You take the project evaluation to the National Insurance Institute (INS) who charge a larger fee for insuring your workers against accidents, about 2% I think.
- With your insurance certificate, architectural plans, Plan Catastro and related certifications you are ready to submit everything to the local municipality (municipalidad). Its fee is between the INS and CFIA's, toward the high side, approximately 1.5%.
In theory you can do most of this yourself but it is common to get an architect or engineer to help.