Casement windows are always a better choice over Sliding when sound insulation is the major concern. You may offer Tilt & Turn Windows
and Tilt & Slide Door systems for best results.

DGU or IGU are preferred mainly for Heat Insulation. In addition it can provide decent amount of sound insulation as well. Hence you will find most of the Centrally Air conditioned offices / Hotels having DGUs. These can be coated with special films/ chemicals to have low emissivity thereby offering better heat/UV insulation.

Its a common myth that insulated glass provides a good acoustic shield. This is NOT COMPLETLY TRUE. In fact a 6mm+12mm air
gap +6mm insulated glass provides less acoustic insulation than a 12mm monolithic glass at most frequencies. Laminated glass on the other
hand provides far superior acoustic insulation when compared to insulated glass; as much as 5-12dB extra-protection over low frequency
range, which is the traffic-zone. In order to use DGU for sound insulation the ideal air gap should be more than 40mm

DGU stands for Double Glazing Unit & IGU stands for Insulated Glazing Unit. Both have same meaning.

EPDM gasket can be sulphernated as well as non sulphernated, AIS Gasket is non sulphernated which is costly. Locally supplied gaskets
contain sulphur.

EPDM rubber is a synthetic rubber polymer developed in the 1960s. EPDM is an abbreviation for Ethylene Propylene Diene Monomer.

Depending upon which brand of fixing materials are used the vendor can provide the details. Ideally the screw should penetrate the wall by
50mm to have good strength. But all the guidelines such as position of the screws/ fasteners , distance between each screw etc. must be
adhered to while doing the installation.

Pls refer the RAL installation guidelines. Sealant to be used should be suitable for PVC application. If you use general purpose sealant it may cause the problems.

Particle boards, MDF panels or any other panels can be used as long as it fits into the profiles.

Yes, as long as the thickness is suitable for Glazing bead