New Construction Data Remains Underrepresented in MLS as Standards Slowly Evolve

The mismatch between how multiple listing services (MLS) were built and how new construction actually works has created persistent challenges for builders, agents, and buyers, and the industry has only recently begun to address it, according to Bill Gaul, CEO of Builders Update and chair of the RESO Data Dictionary New Construction Subcommittee.

Gaul explains that MLS data infrastructure was designed around resale transactions and was not originally built to reflect how builders manage and sell inventory. The consequences are concrete: agents routinely show buyers a listing found in the MLS, only to arrive at a development and discover not one home but fifteen nearly identical models. The listing represented a single unit; the reality is a sales operation with its own pricing strategy, customization options, and construction timeline. Agents who haven't specialized in new construction can find that environment harder to navigate, and buyers end up confused.

Gaul spent roughly a year working through RESO's subcommittee process to address basic terminology problems, such as the inconsistent use of terms like "under construction," "to be built," and "quick move-in" across systems. "It took me about a year of developing consensus among the group. We finally got it to where it's usable for builders," Gaul says.

One of the less-discussed reasons new construction is underrepresented in MLS data is that builders often have good business reasons to list selectively. When a builder lists a home in the MLS, they are typically required to report the sale price once it closes, and that disclosure can complicate pricing across a development with multiple similar units. Gaul compares it to a car dealership: if buyers could see exactly what the last customer paid for the same vehicle, every subsequent negotiation would start from that number. "Builders will only put their model home in, maybe a couple of other models. They're not going to put everything in," Gaul says.

The data-standards problem is compounded by limited agent training specific to new construction. Licensing programs teach agents how to handle resale transactions, but the skills required to represent a buyer at a new construction development—understanding construction timelines, interpreting floor plans, navigating builder contracts, and knowing how to sequence visits—are not typically part of standard training. "They don't teach agents how to sell new construction. They teach how to resell, but not new construction," Gaul says.

Gaul's company, Builders Update, has developed a training program for agents selling new construction, structured as a self-paced course with six modules. The platform takes inventory data directly from builders rather than through third-party aggregators, time-stamps every listing, and performs quality-control checks before publishing. Gaul describes catching errors including listings priced at $1,500 instead of $1.5 million and GPS coordinates placing properties far offshore. Because construction status and pricing can change within weeks, data that passes through multiple intermediaries before reaching a consumer portal can be out of date by the time a buyer sees it. "We want to become the pure source for new construction data," Gaul says.

The platform currently serves approximately 858,000 agents nationwide and is expanding internationally, with the site now available in nine languages and nine currencies. Gaul's recent ambassadorship with the GDX global MLS network is intended to extend that reach, connecting US new construction inventory with buyers in Latin America, Europe, and beyond. The RESO data dictionary changes Gaul has pushed through have moved from the subcommittee to a broader vote, where organizations less focused on new construction may be more cautious about change. As builders represent a growing share of available inventory in many markets, buyers searching through MLS-based tools will continue to see an incomplete picture of what is actually for sale until those standards catch up.