Welcome to 3503 Hillbrook Circle, an impeccably maintained 4-bedroom, 2.5-bath home on a quiet cul-de-sac in desirable Highland Hills of Northwest Hills. Filled with natural light, this thoughtfully designed home blends timeless style with exceptional energy efficiency for comfortable, sustainable living. A special feature of this property is its established bird-friendly landscape. Rich eucalyptus hardwood floors, 8' to 9' ceilings, energy-efficient windows, & multiple living and dining spaces create an inviting atmosphere. The updated kitchen features white cabinetry, granite countertops, an induction cooktop, & energy-efficient stainless steel appliances. The main level also offers a spacious great room with fireplace, separate living & dining rooms, laundry room, & half bath. Upstairs, the primary suite includes a cedar walk-in closet & bath with freestanding soaking tub & separate shower, plus three additional bedrooms. Designed for efficiency & resilience, the home includes solar panels with battery backup, energy-efficient HVAC including a hybrid heat pump, newer fiberglass insulation, fully insulated garage, Class A impact & fire-resistant roof, EV charging outlets, a rainwater collection barrel & irrigation systems. The backyard is a special haven for birds where mature trees & native plants create a peaceful setting birds enjoy year-round, making it especially appealing to bird lovers & nature enthusiasts. Two patios & a private balcony offer quiet outdoor spaces, while a Haikubox bird song monitor identifies visiting species. Sellers are offering one year of professional gardening support focused on preserving the native landscape & thriving wildlife habitat. Convenient to shopping, restaurants, grocery stores, MoPac, RM 2222, The Domain, & downtown, this exceptional home offers modern comfort, sustainability, & an unbeatable Northwest Hills location.