Regarding the addition of fire protection work, the reason is shortage material in the market for the installation project. Hence, the installation progress is affected and deferred due to late delivery of material.
Regarding the additional fire protection work, the installation project has been delayed due to the late delivery of materials, which are currently not easily available in the market.
One day of additional fire protection for the project is therefore required to apply in order to avoid any interruption of services in building during the installation work.
I'm afraid I don't really understand this part.
I would be grateful if you could approve the addition cost of fire protection work for the completed project.
I would be grateful if you could approve the additional cost of the fire protection work to complete the project.
Please forgive me if I'm wrong. I'm not a native speaker of English.