Carpenters are usually aware of persons dealing with aluminum who do window work. So when the Interior work is going on, he will suggest you with the same.
Aluminum and steel dealers also do fabrication work too, so you don’t have to worry about the work as their expertise will not only give you perfection but also quality and guaranteed work. Quality of Hardware like bearing, locks, sections, etc. used would also be of good quality.
If not carpenter, you yourself can visit shops for the window work n choose the best to get sliding windows. Also, the pricing of hardware and sections of sliding window will vary with locations. Even if you go to buy branded i.e. Jindal company sections, price will vary minimum by 10/- to 20/- .
Some carpenters can do sliding windows, but lack of expertise on this field will not give you the perfection and quality of work that the aluminum dealer and his workmen will.
Once the sliding windows are ready, check with the sliding movement of the panels, if they are smooth. Look for the gaps between panels and bottom section. Check if the lock used is not very hard. If the gaping is more, it can be rectified by filling it with silicon.
Low quality of sliding material takes few months before the smoothness of sliding goes down. Joints come apart. Ball bearings if of low quality, will go bad & smoothness in play will go down.
At ContractorBhai we have strict instructions to all team member not to use low quality material. Unfortunately, many times other contractors under quote us. At first it looks very attractive to hire someone who is 10-20 cheaper, but implications are known only after few months pass by.