Meet the Upside Realty Team

The founding partners at Upside Realty, LLC are real estate attorneys and demonstrated entrepreneurs with a deep respect for their clients’ long-term objectives and budget considerations. The Upside Realty team is led by corporate and transactional attorney MR. Juan Carlos Stolberg, who has represented clients working in a variety of fields, including real estate developers, fund advisers, tech startup founders, beverage distributors, restaurant owners, and more. Since 2003, Mr. Stolberg has been a Director at the Stolberg Group, a commercial and residential real estate holding company based in Old San Juan, Puerto Rico, responsible for overseeing and managing over 25 units in the old city alone.

Ms. Sashira Cortés joins Upside Realty as Operations Director, where she oversees all the firm’s management processes and client accounts. Before joining the team at Upside Realty, Sashira spent more than three years working in the financial space managing accounts and performing auditing and quality control. The Upside Realty team is pleased to move our clients closer toward their real estate purchasing, selling, and investment goals with efficiency and professionalism.

At Upside Realty, we understand all aspects of commercial and residential real estate as well as the legal aspects of the real estate industry in Puerto Rico. Get started on your real estate journey with a team of reliable, reputable professionals. Invest. Add Value. Profit. 



Juan Carlos Stolberg



Sashira Cortés



Giancarlo Gonzalez Ascar

418 + 419 NORZAGARAY + SOL ST. OCEANFRONT SPANISH COLONIAL ARCHITECTURE DATING TO THE 1900S IN HISTORIC OLD SAN JUAN - Owner-occupied residential property with seven/eight income-producing rental units (27% Leased). Five stories with the potential of renovating and converting into one spectacular single residential unit. Unique M-FAM in the Historic District of Old San Juan. Oceanfront uninterrupted and protected view to OSJ Federal Park and San Cristobal Fort of the 1800s. Rooftop terrace with pool structure and potential for an off-the-grid setup and more! Unique property with convenient dual access via North 418 Norzagaray St on the North or South 419 Sol St. on the Southside. Unheard of, the property parking features a double back-to-back garage. 5,429 Sq Ft of Construction on a 205 m2 lot - Eight individual units with bathrooms. A shared kitchen area with a large joint family area. Some units have their own kitchen/living and dining areas. The property can be maintained as an income source or "gutted" to create a uniquely private and custom-built home. Good demand for short and long-term rentals - CASH ONLY AND POF REQUIRED - Please call to coordinate an onsite VIP or virtual showing! Thank you! - ACCESS: Dual Access from Northside Nortzagaray or South side Sol St. - APTS: Eight income-producing apartments. - BATHR: Ten Bathrooms - BUILT: 1800'S (initially part of the San Cristobal Fort). - PARKING: Two back-to-back garage PK with St access on Norzagaray. - POTENTIAL: Cafe Bar on the lower level potential Property can be maintained as an eight-unit income-producing unit or converted into a single private home for the very selective individual. - PROP TAX: $2,890 Annually. - SQ FT: 5,429 Sq Ft of Construction - SQ MTS: 205 Sq Mts Rectangular land lot - STAIRS: Spiral staircase on the Northside and Straight staircase on the Southside. - ST ACCESS: Dual North and South street access via Norzagaray on Northside or Sol St on the Southside. - STORIES: Five Stories and a rooftop pool structure. - VIEWS: Uninterrupted and secured Oceanfront views to a VSJ National Park and Fort San Cristobal. - ZONING: R-6 $4,000,000 Active

418 Norzagaray Street 419 San Juan, Puerto Rico

10 Beds 9 Baths 5,429 SqFt 0.050 Acres

Fully redesigned with a glorious rehab that completed in 2009 and located on one of the most peaceful and private streets in Old San Juan, 406 Luna embodies the unique splendor that exists within this historic city. Steps from the architecturally impressive San Cristobal Fort, the homes’ utterly impressive detail and elegant decor, transport you to another era. Built by the Spaniards in the 19th century, 406 Luna boasts original preserved details and hand painted frescoes throughout, crafted personally by the artist in this loving revival. A unique masterpiece, this 5,600 Sq. Ft. interior, + 1,500 of exterior and courtyard living is adorned by impeccable design elements such as 14ft. + original wood and tile beam ceilings, masterfully laid original marble flooring, clay and brick walls as well as interior gardens, truly exemplify the unique contribution the Europeans imparted to the Americas. Terraces and walkways line each floor’s outdoor interior spaces, culminating in two extraordinary rooftop patios. Complete with exercise/ dance studio, fully operational recording studio, and outdoor kitchen/ artist’s studio, every ideal amenity is attended to on property. Unique to this historically acknowledged home, and rare even to the Old City, is the fully equipped indoor spa pool, providing the idyllic repose to a long day, and enhancing the magical allure of this exquisite residence. This property is a historical property and enjoys a ten year renewable property tax exemption. The pool is located off of the interior courtyard, which is open air. It is an in ground, full resistance spa pool, located in its own interior room that is exposed to your courtyard. The courtyard level of the home contains a full artist’s studio with a full kitchen, dance studio/ gym and swimming pool with outdoor shower, semi enclosed. Old San Juan is the epicenter of Puerto Rican culture and is dotted with several UNESCO World Heritage Sites. It serves as one of the leading tourist destinations in the Caribbean and its celebrated buildings are renowned for their elegance and historic significance. The area is known for its numerous dining, shopping and nightlife options. Minutes away from Condado Beach and the Miramar Arts Districts. Walk along the cobblestone streets and experience the mesmerizing vibrancy of what we call El Viejo San Juan. $3,800,000 Active

406 Luna Street San Juan, Puerto Rico

7 Beds 8 Baths 5,600 SqFt 0.160 Acres

**UNDER CONTRACT*** Multi-level Spanish colonial gem located in the heart of Old San Juan. Built in the 1800s, this 5-bed, 6.5-bath historical treasure encompasses over 5,012 Sq. Ft. of interior space and 1,885 of exterior space divided into three floors. Exposed beam ceilings, partial marble flooring and arched entryways are some of the home’s many highlights. The second level serves as the residence’s main floor, featuring a brand new designer kitchen and ensuite primary bedroom, in addition to a spacious living area and family room that lead out to a balcony overlooking the city. The third level showcases a sizable covered/uncovered terrace with South and West exposures. The first floor has two guest suites with independent kitchen/dining areas that can be converted into apartments for short-term rentals. The property also includes a 1-car garage, a rare and coveted find in the old city. Old San Juan is the epicenter of Puerto Rican culture and is dotted with several UNESCO World Heritage Sites. It serves as one of the top tourist destinations in the Caribbean and its celebrated buildings are renowned for their elegance and historic significance. The area is known for its numerous dining, shopping and nightlife options. Minutes away from Condado Beach and the Miramar Arts Districts. Walk along the cobblestone streets and experience the mesmerizing vibrancy of what we call El Viejo San Juan. $3,199,000 Pending

410 Luna Street San Juan, Puerto Rico

5 Beds 7 Baths 5,012 SqFt 0.070 Acres

Take the journey throughout this 5,500 sq. ft. piece of history. An exquisite contrast of modern amenities and beautifully preserved Spanish colonial architecture dating back to the 1600s. As you come in by the “zaguán”, you will be entering through the first of three “historic rooms” so designated by the Institute of Culture of Puerto Rico. The historical integrity of the property is evident in the architectural portholes known as "ojos de buey" – a type of cut-out window used to provide cross ventilation. Above the remaining original wooden doors, you can appreciate the semicircle shaped fanlight windows known as "soles truncos". First Floor: 16’ ft. ceilings make the already impressive first floor seem even grander. A lush interior courtyard patio serves as the unifying element providing natural light and cross ventilation, although all rooms are equipped with air conditioning. Formal living and dining rooms. Family room with built in storage and a half bath. Guest room with a full bath. Comfortable and private home office. Additional office or multipurpose room. Second Floor: An elegant wooden balcony hangs above the courtyard and serves as an outdoor space. Master suite with spacious ensuite bathroom, sitting area with a large skylight and a private rooftop terrace. Three additional bedrooms each with private bathroom. Third Floor: Array of solar panels. Amenities: - Two (13.5 kWh) Tesla Powerwall 2.0 batteries - 7.015 KW solar system that covers approximately 90% of the property's energy requirements. (23 solar panels) - Subterranean water cistern (aljibe) with a 12,000-gallon approx. capacity - Reverse osmosis water purifier. - Two electric water heaters and one gas water heater. Features: - Total GLA: 5,500 sq. ft. / 226 sm lot. - 4,000 sq. ft. of interior living space + 1,500 sq. ft. exterior (semi-covered courtyard and rooftop terrace). - Zoning: C-3 - The property is currently being used as a single-family residence, but zonification allows for various uses such as a multi-tenant apartment building, a historic guest house or operated as a mixed-use commercial-residential property. - Property Taxes: The property is certified by the Puerto Rico Institute of Culture for having maintained historical integrity and is exonerated from paying property tax fees and rental capital gains until 2026. The certification is renewable. - Historical Notes: The property was once home to Juan Tizol, famous Puertorrican Jazz composer who wrote music showcased by Duke Ellington, Nat King Cole, Ella Fitzgerald, and many other world-renowned musicians. The property was also used as a music school. $2,895,000 Active

103 Calle De La Cruz San Juan, Puerto Rico

8 Beds 6 Baths 5,500 SqFt 0.050 Acres

Create the ideal space for your business within this exceptional 3-level commercial building in the highly coveted area of Old San Juan. Remodeled to Fortune 500 Corporation standards. Showcasing an exquisite Spanish Colonial design that appeals to all and an approx. 600 Sq. Ft. terrace with city views, rarely are one of a kind properties such as this available on the market. Two separate entrances are provided for added accessibility, as well as a bathroom and five powder rooms that are evenly distributed throughout the sizable approx. 8,513 Sq. Ft. interior layout. Equipped with a top electrical system and a versatile floorplan that can be customized to your taste. The unique opportunity of using the third floor as an apartment for short-term rentals or as a main residence above the two lower stories is also conveniently available. The location enjoys heavy foot traffic and is situated near many popular venues, such as multiple acclaimed restaurants and La Fortaleza, the governor's mansion. Old San Juan is the epicenter of Puerto Rican culture and is dotted with several UNESCO World Heritage Sites. It serves as one of the leading tourist destinations in the Caribbean and its celebrated buildings are renowned for their elegance and historic significance. The area is known for its numerous dining, shopping and nightlife options. Minutes away from Condado Beach and the Miramar Arts Districts. Walk along the cobblestone streets and experience the mesmerizing vibrancy of what we call El Viejo San Juan. $2,300,000 Active

354 Fortaleza Street San Juan, Puerto Rico

1 Beds 6 Baths 8,513 SqFt 0.070 Acres

Distinguished and elegant, this fine historic property has all the charm and character of past centuries within its time-honored walls. Showcasing the architecturally significant features intrinsic to Old San Juan; a lush interior courtyard with Spanish style stone water feature, authentic marble floors, mahogany balustrades and soaring “ausubo” beamed ceilings. The main level boasts a grand living room which opens to the most exclusive, residential block on San Sebastian Street. Take the stairs down to a private dining room and kitchen that opens to the courtyard. On the second level, two bedrooms with views to the courtyard and a full bathroom. The stately owner's suite on the third level has a bright, sunlit private terrace with a beautifully manicured selection of tropical flowers and plants, overlooking the street below. A large antechamber opens to a luminous bedroom flanked by three large windows, and an ensuite bathroom. Truly flawless, a classic example of Spanish Colonial architecture in one of the few exclusively residential areas within the Historic District of Old San Juan. This is a certified historic property and boasts a tax exempt status as granted by the Institute of Culture. $2,200,000 Active

271 San Sebastian Old San Juan, Puerto Rico

3 Beds 3 Baths 3,196 SqFt 0.030 Acres

Sensationally Luxurious and Fully Furnished Residence! Idyllically situated in a sought-after historic area of Old San Juan, this stunning 4BR/2.5BA, 2,100 sqft property warmly welcomes with a classically vibrant exterior and grand solid mahogany double entry doors with rustic solid bronze hardware (never rusts and offers hurricane protection). Step inside the impeccably styled interior to discover soaring 14’ ceilings, tons of shimmering natural light, an organically flowing floorplan, exposed wood ceiling beams, and gorgeous floor tiles flooring in a traditional black-and-white checkerboard pattern. Catering to the desires of modern entertaining, the spacious living room features plush mod furnishings, bright track lighting, and a discreet dry bar. Adjoining the living area, the formal dining room is cheerfully sophisticated with a unique chandelier, a table for six-plus people, and shelving for the display of treasures. Continue onward to find an uber-chic galley kitchen with sleek contemporary cabinetry, stainless-steel appliances, marble countertops, and direct access to the breathtaking interior patio. Lush greenery, lounge furnishings, and multiple French doors add to the resort-inspired aesthetic of this blissful private retreat. Fabulously sized with posh furnishings and a built-in backlit shoe/clothing wardrobe, the primary bedroom impresses, while the sumptuous attached full bathroom luxuriates with dual raised basin sinks and an oversized custom shower. Two additional bedrooms and one full guest bathroom radiate upscale vibes. Having previously solicited the assistance of an architect, the property also has an available floorplan to extend the home with a 2nd floor. Other features: laundry room, storage room, water cistern, minutes from beaches and shopping, and more! Get all the advantages of this luxe property and start living the good life in one of the USA’s oldest historic cities. Call to schedule your private showing! $1,950,000 Active

257 Calle San Sebastian Old San Juan, Puerto Rico

4 Beds 3 Baths 2,100 SqFt 0.050 Acres

One or more photo(s) has been virtually staged. Descripción de la propiedad: Ultra-Luxurious and a few days away from a Completely Renovated Home with Ocean Views and Tesla Solar! Picturesquely located on one of the most coveted streets in Old San Juan, this 2BR/2BA, 1,900sqft residence is a feast for the senses with a gorgeous exterior featuring a cheerful color scheme, luscious tropical greenery, and rustic double entry doors with solid bronze hardware (never rusts and for hurricane protection). Seamlessly integrating classic style and modern finishes, the first-floor masterfully enchants with beautiful flooring, high ceilings with exposed wood beams, solid mahogany doors, an openly flowing floorplan, over 15,000lbs of imported Italian marble, an enormous living room, and a luminous open courtyard. Nestled on the first-floor, the primary bedroom has a built-in wardrobe, direct courtyard access, and a dream-worthy attached full bathroom with premium finishes, modern storage vanity, custom shower, and hallway access. One additional bedroom is generously sized with a built-in wardrobe and a concealed area for a stacked washer and dryer. Explore the second-level to find a spacious dining room, a chic full bathroom, and a brand-new gourmet kitchen featuring stainless-steel appliances, sleek custom cabinets with soft-close drawers and pull-out organizers, a farmhouse sink, an electric range/oven with a custom hood vent, and French doors leading to the showstopping terrace. Envision lounging with loved ones and watching the magnificent sunsets and sunrises over El Morro and San Cristobal. No matter the time of day, the sparkling ocean offers a hypnotizing backdrop for both work and leisure. Other features: new sidewalk, new plumbing, new electrical, solar panels with 2 Tesla batteries (powers entire home), all custom made mahogany doors and windows (fitted out with doubled paned, insulated, impact resistant, low E glass for sound proofing and hurricane protection) ,5 A/C units (multi-split system), solar water heater, 50-year commercial-grade PVC roof, refurbished cistern plumbed with city water, whole house water purification, UV sterilization, and softening system, near shops and restaurants, and much more! Schedule a tour today! $1,900,000 Active

256 Calle Norzagaray Old San Juan, Puerto Rico

2 Beds 2 Baths 1,900 SqFt 0.040 Acres

4-White (1)

151 San Francisco St. Suite 201
San Juan, Puerto Rico 00901
(787) 725-3191