How do you find the Sound Transmission Class?

Find the average transmission loss: Add up all the total frequencies you recorded, then divide that number by the total number of frequencies you tested. For example, if you recorded all 16 frequencies, divide your total by 16. The number you calculate is your STC rating.

What is a good STC rating for walls?





Table of commonly accepted noise perception in walls: For multi-family construction, the minimum IBC code is STC=50. However STC=60+ is recommended for party walls in higher quality construction such as hotels, townhomes, condos, and certainly quality home theaters.

How do I get a 50 STC rating?

Add Soundproofing Membranes: If you need to achieve an STC of 50 or higher, consider using a soundproofing membrane. These products offer decoupling by separating the drywall from studs, and also significant mass increases.

How is STC calculated?

Here’s how to calculate how many STCs you are eligible for: Solar system size (kW) x Postcode Zone Rating x Deeming Period (years) = Number of STCs (rounded down).

How many decibels can go through a wall?

Measuring sound transmission





30 dB has little sound-control effectiveness. 35 dB allows normal conversation to be heard through the wall. 40 dB allows loud conversation to be heard through the wall.

How is STC of wall assembly calculated?

A few examples:

  1. 5/8″ metal studs, 5/8″ drywall (2 layers total), No insulation = STC of 38-40.
  2. 2×4 stud, 5/8″ drywall (2 layers total) Plus Batt insulation = STC of 34-39.
  3. 5/8″ metal studs, 5/8″ drywall (2 layers total) Plus Batt insulation = STC of 43-44.

What is a good Sound Transmission Class?

Sound Transmission Class (STC):

STC Performance
50-60 Excellent
40-50 Very Good
TruStile Doors with Correct Gasketing 35-40 Good
30-35 Fair

Is STC 40 good?



Acoustic standards, guidelines and building rating systems occasionally permit an STC rating as low as 40. However, most require blocking levels of STC 45 or higher1. An STC 40 level of blocking should be considered a minimum as privacy cannot be achieved at levels below STC 40.

What is the STC rating for 5/8 drywall?

between 30-34

With two sheets total, of 5/8” drywall utilizing standard insulation we often see STC ratings ranging between 30-34. With two total sheets of ½” drywall (common for residential interior walls) we usually see an STC rating of around 33.

How many STC can I claim?



You can claim small-scale technology certificates (STCs) by assigning them at the point of sale to a registered agent like a retailer or solar installer. Each STC claim is unique to an installation. However, you can make more than one STC claim if you use different addresses for each installation.

What does STC 50 mean?

A sound blocking level of STC 50 means that a listener in a quiet room would need to exert effort to hear raised speech levels in adjacent rooms, and the speech would not be understandable or disruptive.

Can I claim STC twice?

The answer is essentially yes, as long as both the properties have different addresses.

What is the STC price today?

Latest Spot Trades

Scheme Price Volume
STC $39.95 30000
VEEC $54.00 15000
ACCU $28.50 10000
LGC $47.25 25000

What is current STC rebate?



The roof has space for 17 x 320W solar panels, totalling a 5.44kW system size. They wouldn’t be installing the solar panels until 2021. With the current STCs price at around $37 per certificate. 75 STCs x $37 this would equate to a STC rebate value of $2775.

Can you claim STCs on replacement panels?

Currently, if one or more solar panels in a system requires replacing, STCs can be claimed on the replacement modules.

What is a registered STC?

Small-scale renewable energy system owners and registered agents have the option to sell small-scale certificates (STCs) through the open market for an uncapped price, or through the STC clearing house at a fixed price of $40 (ex GST).

Is there a minimum PV KWP size when claiming STC?

The system is considered a device that is 100 kW or less and therefore could be eligible for STCs under the Small-scale Renewable Energy Scheme.

Can you claim the solar rebate more than once?



Can I Claim Solar Rebate More Than Once in NSW? You can claim the NSW government solar rebate for solar pv panels once during your lifetime. If you later install another solar system on your property, you will need to wait until after you have claimed the first rebate before applying for the second one.

How is STC rebate calculated?

Calculate solar rebate by using the following formula: Total Solar Array Combined Wattage x 1.382 x the current STC multiplier of 10-years / 1000. The resulting number is the maximum STC’s one is entitled to. Multiplying the number of STCs with the current market value will give the rebate amount.

Can you still get free solar panels?

Companies offered to rent your roof space for up to 25 years, taking care of the solar panel installation and maintenance for free. In return, these companies would collect the money from the FIT. In this way, you got free solar panels for your home.