Hello. I appreciate that's a significant and unexpected increase.
There are things you can do.
1. Have you checked your tenancy agreement, whether there are any rent review provisions to say what he can do to raise the rent. To be honest, I wouldn't expect there to be, so will assume not, if there are provisions then these must be followed.
2. How much notice have you been given. A landlord is required to give the tenant sufficient notice before a rent increase is to take effect. For a monthly, weekly or fortnightly tenancy one month's notice of the intended increase is required. For a yearly tenancy, a period of six months' notice is required. You are probably on a rolling assured tenancy, in which case it would be reasonable to ask for 6 months notice.
3. Has it been done properly by the landlord or did he just tell/write. They should be sending what is known as a Section 13 Notice which is a way for landlords to increase the rent they charge for a property. It refers to Section 13 of the Housing Act (1988). Landlords can only use Section 13 for assured periodic tenancies. ... The rent increase being proposed by the landlord must be fair and realistic.
4. The CAB has set out some really good advice about challenging a rent increase, see
5. You can also try to find out what a fair rent for your property should be - at the Valuation agency https://www.rbkc.gov.uk/contactsdirectory/az.aspx?orgid=1378&
6. I realise that you have done work to the property but as you were not "forced to" (or the landlord should have maintained the property), this is useful to use in negotiations with him/her as a bargaining tool but probably not for much else as you choose to do the works at your cost.
I trust that these answers help with your questions. Happy to clarify any of it.