Percentages: value of the land (and buildings?) or area of the land. I want to create a Tenants in Common with my son. I believe Tenants in Common works with percentages of ownership under property law, e.g. 50%, 30%. I would rather have the agreement delineating an area of land that is a natural separate section, being divided by a proposed road easement. It is difficult to work out percentages based on value because I am building a house on the land. If I say 50% of the land, being the area of the separate section, may this be taken to mean 50% of the value? Are buildings or improvements counted in working out a percentage? If so, should I wait until the house is built, a valuation done and a new percentage worked out that reflects the percentage value of the separate section of land? The value of the separate section of the land is lower than the section that I want for myself as it is prone to flooding. I estimate the value of the separate section that is 50% in area is about 30% in value of the land.