Tenants will enjoy reduced energy bills:

By upgrading the energy efficiency of the property, it will be easier for landlords to rent their properties out because tenants will enjoy reduced energy bills compared to a similar property that has not had energy efficiency upgrades.

Reduces Carbon Emissions:

By upgrading the energy efficiency of the property, it then falls inline with the government’s directive of becoming Net Carbon Neutral by 2050

Landlords comply with MEE regulations:

As a responsible landlord you will obviously know that any property you rent out must fall in line with the April 2020 regulations on the minimum EPC rating to avoid up to £5,000 fines. Minimum Energy Efficiency Standards (MEES) for Landlords
Minimum requirement for all rented properties MUST be an EPC rating of E – that will rise to a ECP rating of C in 2025.
Local councils are now starting to enforce these regulations and issuing the appropriate fines to landlords.

The value of the property increases:

It goes without saying, upgrading the fabric of the property will only increase its core value.
If you ever decided to sell the property, the sale would be far easier having energy efficient upgrades.