This 1931 Tudor-style residence is a rare and beautifully preserved example of early 20th-century architecture, thoughtfully maintained and enhanced by its architect owner. Located on Donaldson Avenue in Monticello Park, one of San Antonio's most distinguished historic neighborhoods, this home offers an exceptional blend of authenticity, craftsmanship, and modern refinement. The stone-clad exterior immediately conveys architectural pedigree, with textured masonry, steeply pitched rooflines, and subtle asymmetry emblematic of classic Tudor design. Mature trees and the surrounding collection of architecturally significant homes further elevate the sense of place, reinforcing Monticello Park's reputation for timeless elegance and preservation-minded pride. Inside, the home spans 1,737 square feet, featuring 3 generously sized bedrooms and 2 baths, a notable rarity for homes of this era. Each bedroom is impressively proportioned-truly oversized by historic standards-offering flexibility for comfortable living, guest accommodations, or dedicated work-from-home spaces. The primary suite is both inviting and functional, highlighted by a walk-in closet and an updated en-suite bath. The bathroom renovation is tastefully executed, featuring a walk-in shower enclosed with frameless glass, creating a clean, refined aesthetic that feels both contemporary and timeless. Throughout the home, original hardwood floors flow seamlessly through the living spaces, anchoring the interior with warmth and continuity while showcasing the superior materials and construction standards of the era. Original windows remain intact, preserving authentic proportions and allowing natural light to filter in with a soft, enduring quality rarely replicated in modern construction. The interior layout reflects classic residential design, offering well-defined spaces that strike a thoughtful balance between intimacy and openness. Generous ceiling heights, solid wall construction, and original architectural details create a sense of permanence and quiet sophistication. A beautiful fireplace serves as a focal point in the main living area, ideal for both relaxed evenings and elegant entertaining. The kitchen has been tastefully updated to meet modern expectations without compromising character. It features a ZLINE dual-fuel range and oven, paired with a ZLINE dishwasher, blending professional-grade performance with refined design. Painted cabinetry and updated hardware provide a clean, tailored finish that complements the home's historic aesthetic. Behind the scenes, meaningful investments have been made to enhance comfort, efficiency, and long-term performance. Recent improvements include new gutters, expanded attic insulation with an impressive 15-inch depth, and HVAC supply and return upgrades designed to improve airflow and climate control. Select drywall enhancements and a comprehensive interior repaint, covering all primary living spaces, further elevate the home's overall presentation. Set among the tree-lined streets and architecturally significant homes of Monticello Park, this residence offers more than a place to live, it offers architectural legacy. Thoughtfully preserved, intelligently updated, and rich in character, 531 Donaldson Avenue presents a rare opportunity to own a historic San Antonio home that lives beautifully today while honoring its past.