In Sunfield, the Builder's Rate Has an End Date. The MUD Tax Doesn't.

"Starting in year 8 the ARM interest rate may increase every six (6) months." That line comes from the bottom of David Weekley Homes' Sunfield page, below the headline offer of a starting rate as low as 4.99% on select quick move-in homes in the Austin area. Most buyers comparing a new Sunfield home with an older resale in Buda or Kyle start with the rate. The rate offer has an end date in its own fine print. The second number, which doesn't, is the tax line that takes the place of a city tax in Sunfield.

The rate offers, read to the last clause

This fall, two builders in Sunfield are advertising financing offers. Here is what their own terms say.

• David Weekley Homes. The 4.99% figure is the starting rate on a 7/6 adjustable-rate mortgage. A fixed rate is offered "as low as 5.99%." Buyers have to purchase and close on a select Austin-area quick move-in home between October 7 and December 15, 2026, and finance through Priority Home Mortgage. David Weekley has an 80% ownership interest in that lender. Buyers are not required to use it, but the rate offer depends on it. Starting in year 8, the rate follows the 30-day SOFR index plus a 2.75 margin. The first adjustment is capped at 5%, later adjustments at 1%, and the lifetime cap is 5%. The financing pool is limited and first-come, first-served, and buyers "may need to pay discount points" to get the committed rate.
• DRB Homes. The Austin-area promotion advertises 4.99% fixed for the first five years, with a printed APR of 6.645%, or up to 6% in savings on select homes. Its eligible communities include Sunfield in Buda, plus Infinity Square and Opal Ranch in Kyle.

Every one of these terms has an end date: a closing deadline, a five-year window, or a seventh year. A buydown pays down your rate for a set period and then stops.

What Sunfield pays instead of a city tax

Sunfield is a master-planned community of about 2,790 acres along I-35 between Buda and Kyle. Four municipal utility districts make it up, and Sunfield MUD No. 4 also acts as the Master District for the whole development. According to a City of Buda release from June 2024, Sunfield is not inside Buda city limits. It sits in the city's extraterritorial jurisdiction and falls under the authority of the Sunfield MUDs.

That means a Sunfield tax bill has no City of Buda line on it. The MUD line takes its place. Sunfield MUD No. 4's preliminary official statement, dated September 22, 2026, lists every 2026 rate that applies to property in that district:

The county figures in the table match what Hays County adopted on its own. Commissioners Court voted 3-2 on September 15 to set a FY 2027 rate of $0.4097, which is the general rate plus road and bridge. Hays CISD's adopted tax-year 2026 rate of $1.14 also matches.

MUD No. 4 isn't the only district in Sunfield. MUD No. 3 also lists a 2026 rate of $0.90. MUD No. 1's adopted 2025 rate was $0.87, according to the Hays County 2025 rate table. The exact MUD rate depends on which section of Sunfield a home is in.

The $0.90, split into its three parts

MUD No. 4 divides its 2026 rate into three parts:

• $0.13 for maintenance and operations
• $0.5425 for debt service on the district's own bonds
• $0.2275 for "contract tax"

The contract tax pays for the shared infrastructure. Under the Master District Contract, MUD Nos. 1, 3 and 4 each pay a share of the debt service on bonds the Master District issues for Sunfield's regional water supply and treatment, its water and wastewater trunklines, and its drainage and detention facilities. Each district's share is based on its assessed value.

So about 77 cents of every 90 go to paying back borrowed money, either the district's own bonds or its share of the Master District's. The official statement also says the district "has never adopted a general homestead exemption." Filing a homestead exemption on a Sunfield home reduces other lines on the bill, but it doesn't reduce this one.

A district that is still borrowing

A buydown is set at closing and then counts down. The MUD's borrowing keeps growing.

The September 2026 official statement covers a $7,015,000 sale of Unlimited Tax Road Bonds, Series 2026. This is the district's fourth road bond series, all drawn from $70,350,000 that voters authorized for roads. Once this sale closes, $39,095,000 in road bonds will still be authorized but not yet issued. Separate voter authorizations cover the utility system and refundings.

The Master District's numbers are bigger. It has issued five series of contract revenue bonds since 2022 and still has $239,180,000 authorized but unissued for the Master District facilities. It "anticipates that it will continue to issue unlimited tax contract revenue bonds in installments over the next several years." Each sale is meant to happen "at the earliest practicable date consistent with the maintenance of a reasonable tax rate."

The district's own investment considerations also address the contract tax directly: "The levy of a Contract Tax to substantially higher levels could have an adverse impact upon future development and upon development and home sales within the boundaries of all Financing Participants." This is standard bond-disclosure language, not a forecast. Still, it shows that the district itself counts the contract tax as a variable that affects home sales.

The same house with two different tax lines

To see how this plays out, take a real price. DRB recently listed 408 Rubber Tree Way in Sunfield at $399,990 for 2,202 square feet, marked as available now. Use that price as a stand-in for taxable value. The appraisal district sets the actual value, and other exemptions will change the other lines on the bill. Here is how the one line that changes compares:

Buda adopted its $0.3895 rate with the FY 2027 budget in September, and Kyle adopted $0.5460 for FY 2026-27. At the same taxable value, the Sunfield MUD line costs about $170 a month more than the Buda city line and about $118 a month more than Kyle's. These figures are from this one line only and don't account for other districts or exemptions that apply to a particular address.

This is the comparison worth doing next to the rate quote. A rate buydown lowers the principal-and-interest payment for a set number of years. The MUD line applies to taxable value every year, and its debt portion supports bonds that are still being sold. If the buydown savings and the extra tax cost are about the same, they balance only while the buydown lasts.

Market timing affects how builders compete. In September 2026, Unlock MLS data reported by KXAN showed Hays County with 4.8 months of inventory, the lowest of any county in the Austin metro, compared with 5.4 months for the metro overall. The metro median sales price that month was $421,000, up 1.4% from a year earlier. With prices roughly flat, builders in the county have been adjusting the rate a buyer pays more than the price on the listing.

Where the paperwork shows up

Texas law requires the seller to disclose the district before the contract is signed. Texas Water Code §49.452 requires a seller of property in a covered district to give the buyer a written notice before the contract is executed, and the buyer signs to acknowledge receiving it. The same rule applies whether you buy a new build from a builder or a resale from a homeowner inside Sunfield.

When you compare a Sunfield home with a resale inside Buda or Kyle city limits, these questions keep the numbers comparable:

1. Which Sunfield MUD is the lot in, and what is that district's current rate?
2. How long does the rate offer last: a fixed term, a set number of years, or until an ARM's first adjustment?
3. Over that same period, how much more does the MUD line cost than the city line it replaces?
4. What does the district's most recent official statement show about authorized but unissued bonds?
5. On the resale side, which city rate applies, and does the address fall in any other district?

This post is general information, not legal, tax or financial advice. Confirm loan terms with your lender and tax figures with the appraisal district or a tax professional before relying on them.

FAQ

Is Sunfield part of the City of Buda? No. The City of Buda's June 2024 release says Sunfield is not within city limits and sits in Buda's extraterritorial jurisdiction under the Sunfield MUDs. That same month, the city released 695.648 acres of undeveloped Sunfield land from its ETJ.

Does the David Weekley rate offer require its affiliated lender? The 4.99% and 5.99% offers require financing through Priority Home Mortgage. The page also says buyers are not required to use that lender as a condition of buying the home.

Does every Sunfield district charge the same rate? No. MUD Nos. 3 and 4 list $0.90 for 2026, and MUD No. 1 adopted $0.87 for 2025. The Master District facilities don't serve MUD No. 2, so it doesn't pay the contract tax and will issue its own bonds instead.

If you're deciding between a Sunfield new build and a resale inside Buda or Kyle, Better Broker, Texas Realty can help you lay the rate offer next to the MUD line for the specific lot you're looking at, year by year, so you can see what the payment looks like after the incentive ends.