long term lease?

Hi,

Following a previous posters question about leases less than 12 months, is it possible to negotiate a lease of more than 12 months?

The agents I have asked lately all say that they do a maximum of 12 months - is this a requirement or can they go longer if they choose?

Also, if I want to ask the owner of the property a question with regards to making property improvements, is the managing agent obliged to pass on to the property owner any formal correspondence I direct to the owner through them?

I am reasonably handy and am living in an old property. There's lots of improvements I want to do that would be in the owners interest too, but I don't want to do them without either a long lease commitment (in which case I'd be happy to fund them myself), or a commitment from the owner to share the costs?

Cheers.