I have an old 1920's bungalow, got 2 quotes, both told me that all the duct under the house were bad and supply box, etc. cost will be over 2500.00 one said needs permit, one said no need. what is correct? i cant find that info @ the city's web. also, anyone knows a good company in the tampa area? it's such a big job and i am afraid that i will use a bad one. hlp.