If you have occupied your property for 7 years it is almost certainly an Assured shorthold tenancy and as such you are a valuable tenant to the landlord as you pay your rent , do not damage the property and do not act in an anti-social way and without you the landlord will have to find new tenants who may not prove to be of your standing and would probably not take the property without decoration and improvement which may be expensive, but do remember your tenancy can be brought to an end by the landlord without you breaking any terms of the agreement.
You say your tenancy agreement does not contain any provision for what the landlord must do; the usual arrangement is that you are responsible for the interior and the landlord for the exterior plus fitted apparatus. If you are not inclined to pay, what you consider a high rent and carry out decorating, I suggest you contact the landlord in your usual way and see if a compromise can be reached by reducing the rent for a certain period or other arrangement.