Triple Net Cost Reconciliations for Mixed Use buildings
I have several buildings that are mixed use and we complete reconciliations for the commercial tenant annually.  I would like to see what others methods are of assigning the tenant's pro rata share.

We currently take the total square footage of the building divided by the total rentable commercial space and then calculate the commercial tenant's pro rata share by what they occupy.  

I have looked around for literature on this, but either I am searching incorrectly or the information is few and far between.  Thank you for any help.
[{"id": "ioe4kti", "text": "I am very confused, how else would you calculate their pro rata share??  You simply take the tenant's square footage and divide it by the total size of the property which equals their percentage.  You then take your total cost and multiply it by that percentage, thus giving you that particular tenant's pro rata amount.  Am I missing something?", "replies": [{"id": "ioeczw7", "text": "There are alternatives. Sometimes it is appropriate to split costs based upon things other than just square footage. A residential tenant on the third floor shouldn't be paying tax reimbursements at the same rate as the bar on the first floor for example.", "replies": [{"id": "iofllex", "text": "Yea. Back in the day I had to underwrite Dyna (pre ARGUS software) for 300+ tenant malls with like 30 different CAM pools. \n\nFucking nightmare. I avoid retail deals like the plague. Still gives me PTSD", "replies": [], "depth": 3}], "depth": 2}], "depth": 1}, {"id": "ioe5fuj", "text": "[BOMA](https://www.boma.org/BOMA/BOMA-Standards/BOMA_Floor_Measurement_Standards/Mixed-Use.aspx)", "replies": [{"id": "ioevjid", "text": "thanks", "replies": [], "depth": 2}], "depth": 1}, {"id": "ioezun0", "text": "I think of it in two ways:\n\n1. Allocating pro rata shares according to each use (retail, office, residential, etc).\n2. Allocating pro rata shares among tenants with the same use (among retail tenants, among office tenants, etc.)\n\nFor (1), straight square footage is the simplest. If your property tax assessor has a methodology of assessing mixed use properties by separating out each use and assessing those individually, then you can try to match that when allocating across uses.\n\nUtility bills are where you're going to see more creative allocations. For example, allocating the gas bill on a per-appliance basis. Taking off a fixed amount of usage per residential occupant for water, garbage, or whatever else and splitting the rest among the nonresidential tenants based on square footage. RUBS can get pretty complicated on the residential side.\n\nThe more creative the allocation methodology, the more work it is to calculate it.", "replies": [], "depth": 1}, {"id": "iofbiz0", "text": "You\u2019re probably stuck with what you have in the leases. What are you even trying to accomplish with this? Bill utilities back directly and submeter spaces if you want more control.", "replies": [], "depth": 1}, {"id": "iogq18l", "text": "For current tenants you\u2019re going to be stuck with whatever is stated in their lease. \n\nFor future tenants, you can install check meters for utilities. Do waste removal on an agreed upon % based on usage. I\u2019ve seen direct multipliers in leases (ie. tenant to pay 2x prop share). If they have a separate hvac unit, you can make them pay for that separately. If you have any tenants with very large footprints you can exclude them from your GLA altogether. \n\nLarge indoor malls tend to have all these crazy prop share calculations that nobody can figure out. Maybe that works in their benefit\u2026", "replies": [], "depth": 1}]