Fly ash bricks are environmentally very beneficial. They replace clay which has all nutrients for good agriculture. Top soil erosion is an environment hazard and Fly ash bricks prevent this.
The Fly ash bricks not only conform to various standards but also supersede them when made with latest technologies. They have higher compression strength. The water absorbility is lower hence saves upto 20% water usage and also mortar and rendering material by upto 20%. The U value is much better hence the thermal conductivity of the building is much superior. If an AC is used in the house with Fly ash bricks the cooling load is down by upto 20% thus the power bill on air conditioning can be lower by upto 25% and the power bill itself over period of time pay back the cost of bricks used in construction.