Replacement reserves are money set aside every year for the parts of a building that wear out on a cycle longer than a year: roofs, HVAC units, boilers, parking surfaces, elevators. In underwriting they are a deduction per unit or per square foot that turns a smooth NOI into one that admits the building is ageing, and lenders often collect them monthly into a reserve account.
Updated 19 October 2026.
Published by Titleman, which makes underwriting software.
Written by the Titleman team with AI assistance (Claude).
Why they matter more than their size
A reserve line is small next to rent, so it is easy to accept whatever the offering memorandum shows. It matters for two reasons. First, it is capitalised: a reserve understated by USD 50,000 a year, at a 6.5% cap rate, is about USD 770,000 of value that is not there. Second, it is where a building's physical risk enters the numbers at all. If the reserve was not built from the building, the model has no view of the building.
Where reserves sit: above or below NOI
This is the convention that trips people most.
- Below the line. Many broker packages show NOI before reserves. The cap rate in the marketing is then a cap rate on that larger NOI.
- Above the line. Many lenders and appraisers deduct reserves before NOI, and size the loan on the smaller figure.
Neither is wrong. Mixing them is. Before you apply a market cap rate, find out which NOI it was quoted on, and state your own convention in the model.
How to size them
- Start from the property condition assessment. A PCA lists each system with its effective age, remaining useful life and replacement cost. That is the raw material for a reserve.
- Spread each item to its replacement year. A roof with five years left and a USD 400,000 cost needs about USD 80,000 a year if you want the cash ready on time.
- Separate the near-term items. Anything due in the first year or two is a capital expenditure in the budget, or a holdback at closing, not a reserve.
- Compare with the shortcut. Lenders often state a minimum per unit for apartments or per square foot for commercial space. Use the higher of your bottom-up figure and the lender floor.
Reserves in a mixed-use or older building
Different uses wear differently. Retail storefronts, restaurant exhaust, office lifts and residential kitchens each have their own cycles, so one blended allowance across a mixed-use property usually hides the expensive item. Split the reserve by use where the PCA allows it.
What a model should show
In a model you can defend, the reserve line carries its basis: the PCA it came from and its date, or the lender floor it matches. When Titleman builds an underwriting, every input shows its source and date and every result shows its formula, and a figure we could not find, such as a missing PCA, is named as missing rather than filled with an assumption. The underwriting software guide explains what else such a package should carry, and what is included in a commercial underwriting package lists the parts.
FAQ
What are replacement reserves?
Replacement reserves are an annual allowance for capital items that wear out and must be replaced on a cycle longer than a year, such as roofs, HVAC units, parking surfaces and elevators. In underwriting they are deducted as a cost per unit or per square foot, and lenders often collect them monthly into a reserve account.
Are replacement reserves included in NOI?
It depends on the convention. Many lenders and appraisers deduct reserves above the NOI line, while many brokers show NOI before reserves. Always check which one a cap rate was quoted on, because a cap rate on NOI before reserves applied to NOI after reserves understates value, and the reverse overstates it.
How are replacement reserves calculated?
The sound way is from a property condition assessment: list each building system, its remaining useful life and replacement cost, and spread the cost over the years until replacement. A flat allowance per unit or per square foot is a shortcut that hides an old roof or an end-of-life chiller.
What is the difference between replacement reserves and capital expenditures?
Reserves are the steady annual allowance for routine replacements. Capital expenditures in an underwriting are usually one-off projects: a known roof replacement next year, a lobby renovation or a value-add programme. A model should carry both, and not count the same roof twice.