Four numbers frame the whole idea:
The first two are the market. The second two are Bids — and the distance between them is the entire reason to build rather than buy. Start with what the terms actually mean.
What yield on cost actually measures
Cap rate is the buyer’s number: what you pay to own a finished, stabilized rental. Today a single-family rental trades at about a 7.3% cap rate, up 194 basis points since 2021, with lender debt yields pushed to 11.3%. That’s the price of buying cash flow someone else already built.
Yield on cost is the builder’s number. It’s stabilized net operating income divided by total development cost — the same rent, measured against what it took to create the asset instead of what it costs to buy it. Build it right and your yield on cost lands well above the cap rate you could sell it at. That difference has a name.
The spread is the entire game
Here’s the part most pro formas gloss over. Most developers build for a development spread of just 1.5% to 2.5% over the market cap rate. Against today’s ~7.3% cap, that puts a typical new project’s yield on cost somewhere around 9 to 10%. And the industry underwrites ground-up build-to-rent to a 7 to 8% yield-on-cost floor — clear it and the deal gets built, miss it and it doesn’t.
That thin band is doing enormous work. A couple hundred basis points is the entire margin that has to absorb every risk in putting shovels in the ground: a cost overrun, a slow lease-up, a rate move, a quarter of flat rents.
Why ours runs double
New build-to-rent at Bids pencils at a 12 to 15% yield on cost. Against a ~7.3% market cap, that’s a development spread of roughly 500 to 750 basis points — several times the 150 to 250 most developers build for, and about double the 7 to 8% the industry underwrites to.
It doesn’t come from betting rents higher. It comes from cost basis: finished lots at about $29,000 against $45,000 to $61,000 retail, and construction at $108 a square foot. The economics report that maps the national market makes the same point in the abstract — secondary markets win build-to-rent through lower land costs that lift the yield. Wichita is that case, proven to the dollar on completed projects.
What it means if you’re underwriting a deal
Yield on cost is the number that tells you whether a development is worth building — and in a tighter 2026 market, it’s the number that separates a deal that survives from one that was only ever a bet on rents rising. Higher cap rates and flat rents thin a 200-basis-point spread fast. They barely touch a 600-basis-point one. Underwrite here and you’re underwriting a spread with room to be wrong.