I'm a fellow NYS homeowner - do it yourselfer, and have run into this sales tax delema many times. Here's the deal. You are correct that capital improvements on one's Primary residence are sales tax exempt. HOWEVER, ONLY if the improvement is done by a CONTRACTOR. Example: Your house needs a new roof. If you do the job yourself, you MUST pay sales tax on the materials you buy. If a contractor does the job, then entire job is tax exempt. Yes, only in NY do guys like us get penalized for trying to save a buck. I have a feeling construction unions had some effect on how this law was written. Now, in your situation, I would ask who is INSTALLING your purchase? If the dealer does the "Installation", then I would think this would qualify as tax exempt. In other words, the tax you save might pay for the installation, and save you some work. If you are merely buying from the dealer, and installing yourself, you will have to pay tax. And they wonder why the mass exodus from NY continues !