We are replacing the cedar siding on our second floor with either vinyl or cement board. The windows are 27 year old double hung Andersons. There are no problems with the seals, but a few must have problems with the sash weights/cords as they are either hard to open or won't stay open. At some point they will need to be replaced, but they could last for quite a few more years too. Although the cost of window replacement is considerable, we are wondering if it would be advisable to replace the windows while we are replacing the siding. Some of the contractors we've talked to said it doesn't matter if we do the siding now and then the windows a few years later. However, others said it would be much better to do the windows while we are doing the siding as far as installation and final looks. If we replace the windows, they would be wood on the interior and low maintenance on the outside. Pros and cons...we know the big con is the cost, but are there really any pros for replacing the windows along with the siding?