Renting out house

if you are intending to rent your property for "seasonal holiday use" (although this can vary from region to region) in this part of the country is limited to 60 days.More than this constitutes a full blown business.you'll be able to find and very probably in english too on the Regione Toscana official web site the tuscan parameters.Also your local comune will be able to give you some other info as officially one should also register the presences ( ie the identicification of the people staying at your place like with hotels etc) whilst in the past many will have ignored these obligations but in the current climate of "witch hunting" it would be advisable to do it by the books

Isn't there also some ruling on maximum pool depth? I think I heard any deeper than 1m40 and you have to have a lifeguard present! Depth might be wrong but would be worth checking before discovering you have just built a pool which would be regarded as too deep!

You're right about the depth Andiamo.  These rules are regional and it's effectively to prevent drownings and accidents (which has to be the most stupid logic ever). It isn't just for rental properties, it is for communal pools as well, i.e. shared pools in residences/holiday complex even if all privately owned and privately used. The rules are not just re. pool height, but also sanitation and various health and safety measures - just a few include obligation for a foot bath, duck diving etc prohibited, no swimming within 3 hours of a meal, legal requirement to take a shower before entering water, pool area must have a gate - (I repeat this is regional, so it may differ or not apply wherever you are). Some condominiums took the decision to fill in the deep end of the pool, especially where the pool needed some maintenance anyway - taking out the liner and pouring concrete into the deep end, then relining, in order to avoid having to hire a bagnino, which would add a good 7 grand on to the condominium expenses. However, other condominium administrators have found a way around the rules: the rules don't state that the bagnino has to be qualified or full time - in other words, anyone could "ACT" as bagnino while people are in the water. So they have changed the condominium regulations to state that while anyone is in the water, there must be someone at the pool side to "act as" a lifeguard. All this essentially means is no solo swimming and if one person is in the water, at least one other person (a responsible adult who can swim) remains pool side. What happens if the owners/residents ignore this rule? Well, the administrator and/or condominium are covered because they have clearly stated the rules, which must be observed by law, the responsibility shifts to the transgressors. It's essentially a liability thing if anything happens (seeing as a lifeguard is not required with depths under 1.4m, it's obviously not a life-saving measure - especially as you can drown in 3 inches of water anyway!)  

Of course - this is the easiest solution to any swimming pool depth problems! http://movable-pool-floor.co.uk/en

This article may be of assistance: http://www.italymag.co.uk/italy-featured/letting-your-property

You need to look at the regional law 42 which describes the various options and what you have to do. You'll probably need article 56 - Case e appartamenti per vacanze. You'll need to make a declaration at the comune and, as Sebastiano said, report who stays, either to the comune or to the police depending upon the size of your comune