New landlord questions - are these all improvements (not repairs)?

I am a new landlord and I am filling in the tax return at the moment. Here are some questions which I would like to ask for your help.:)-:

1. After I bought the property (before tenants moved in),

• I replaced the old wooden kitchen door to a new PVC door.
• The bathroom originally had no shower. I then found a plumber to replace the old bath taps to a new bath shower mixer tap, added a new shower kit and a shower curtain rail. He also tiled the bathroom walls (only around the bath).

2. After tenants move in, due to the problem of condensation, I added 4 new window vents .

Should I consider all these works as improvements? If they are classed as improvements, does it mean these will be taken into account as capital expenditure in calculating capital gains tax when the property is sold?

Thanks in advance!
Confused landlord