7 Biggest House in the World (Ranked by Size): The Largest Homes Ever Built
The biggest house in the world is Istana Nurul Iman in Brunei. It covers approximately 200,000 square metres (2.15 million square feet), making it the world’s largest residential palace by floor area. It is the official residence of Sultan Hassanal Bolkiah and features 1,788 rooms, 257 bathrooms, five swimming pools, and parking for around 110 vehicles.
If you’re wondering which other homes rank among the world’s largest, this guide compares the 7 biggest houses in the world, explains how they are measured, and highlights what makes each one unique.
If you’ve ever searched for the biggest house in the world, you’ve probably noticed a problem: almost every website gives a different answer. Some rank Antilia first, while others claim it’s Buckingham Palace or Istana Nurul Iman. It’s confusing, especially when none of them explain how they reached their rankings.
While researching this guide, I found that the biggest reason for these differences is the measurement method. Some websites compare land size, others focus on floor area, and some only include privately owned homes while excluding royal palaces. Without a consistent standard, it’s impossible to make a fair comparison.
That’s why this guide ranks every property using total floor area, the most widely accepted way to compare large residential buildings. I also reviewed official government resources, royal household information, and recognised architectural references to verify the facts.
Whether you’re interested in world records, architecture, luxury homes, or simply want a clear answer, this guide will help you understand which houses truly deserve a place among the world’s biggest.
Quick Comparison: 7 Biggest Houses in the World
| Rank | House | Country | Approx. Floor Area | Owner / Resident |
| 1 | Istana Nurul Iman | Brunei | 200,000 m² (2.15 million sq ft) | Sultan Hassanal Bolkiah |
| 2 | Royal Palace of Madrid | Spain | 135,000 m² (1.45 million sq ft) | Spanish State |
| 3 | Buckingham Palace | United Kingdom | 77,000 m² (828,000 sq ft) | British Crown |
| 4 | Antilia | India | 37,000 m² (400,000 sq ft) | Mukesh Ambani |
| 5 | Biltmore Estate | United States | 16,600 m² (178,000 sq ft) | The Biltmore Company |
| 6 | Lakshmi Vilas Palace | India | Approximately 15,000 m² (161,000 sq ft) | Gaekwad Royal Family |
| 7 | Hearst Castle | United States | Approximately 8,300 m² (90,000 sq ft) | State of California |
Note: Rankings are based on total floor area rather than land size. Measurements come from official publications or widely accepted reference sources where available.
How Big Is the Biggest House Compared to an Average Home?
It’s genuinely difficult to imagine just how large the world’s biggest houses really are without a point of comparison. The average newly built single-family home in the United States measures around 2,400 square feet (223 square metres), while Istana Nurul Iman covers approximately 2.15 million square feet (200,000 square metres).
That difference means the world’s biggest house has nearly 900 times more floor space than the average American home. To put that scale into perspective, walking through every room of Istana Nurul Iman would take far longer than exploring a typical family home from front door to back garden, and this comparison alone highlights just how extraordinary the world’s largest residences really are.
How We Researched and Ranked These Houses
Our rankings are based on total floor area (gross floor area), the most widely accepted way to compare very large residential buildings.
To ensure accuracy, we compared official government publications, royal estate information, historic estate records, and recognised architectural references. Where measurements differed, we used the most widely accepted published figures or official data.
We included residential palaces and private homes while excluding hotels, commercial buildings, and public institutions.
Why Do Rankings Differ?
If you’ve searched for the biggest house in the world before, you’ve probably noticed that different websites name different properties as number one, and the reason for this is simple: there is no single worldwide standard for measuring a property.
Some rankings compare total floor area, land size, number of rooms, building height, private ownership, or even historical significance, and each method can produce a completely different “winner.” Antilia, for example, is often called the world’s biggest private house because it’s owned by a single family, yet Istana Nurul Iman is far larger when measured by total floor area and is officially recognised as the world’s largest residential palace overall.
Throughout this article, we use floor area as our measuring stick, since it provides the clearest and fairest comparison across both private mansions and royal residences.
Why Are Palaces Included in This Ranking?
Some readers may wonder why royal palaces appear in a list of the world’s biggest houses at all. The reason is straightforward: many palaces are still genuinely residential buildings, serving as the official homes of monarchs or heads of state while also hosting ceremonies and government events on the side.
Istana Nurul Iman, for instance, is the official residence of the Sultan of Brunei, while Buckingham Palace is the official London residence of the British monarch. Because both buildings are designed for residential use first and foremost, they’re commonly included in global rankings of the world’s largest houses. Private mansions such as Antilia are included for the same underlying reason: they function as permanent family homes rather than commercial or public buildings.
The 7 Biggest Houses in the World, Ranked
1. Istana Nurul Iman (Brunei)
Floor Area: Approximately 200,000 m² (2.15 million sq ft)
When people ask, “What is the biggest house in the world?”, the answer is Istana Nurul Iman. Completed in 1984, this magnificent palace is the official residence of Sultan Hassanal Bolkiah, the Sultan of Brunei. Designed by Filipino architect Leandro V. Locsin, it blends modern engineering with traditional Islamic architecture, creating one of the most recognisable royal residences anywhere in the world.
With a total floor area of around 200,000 square metres, Istana Nurul Iman is more than twelve times larger than America’s biggest privately owned home, Biltmore Estate. It serves both as the Sultan’s private residence and as the venue for official state ceremonies, diplomatic meetings, and national celebrations, making it as much a working government building as it is a family home.
The palace’s scale is genuinely remarkable. It includes 1,788 rooms, 257 bathrooms, and five swimming pools, along with a banquet hall built to host around 5,000 guests. A private mosque provides space for roughly 1,500 worshippers, while the grounds include parking for around 110 vehicles and air-conditioned stables for the Sultan’s polo horses.
Beyond its impressive size, the palace is admired for its golden domes, beautifully landscaped gardens, luxurious interiors, and elegant Islamic design. It remains one of the most famous royal residences in the world and is widely recognised as the largest residential palace ever built.
Quick Facts
| Feature | Details |
| Location | Bandar Seri Begawan, Brunei |
| Completed | 1984 |
| Architect | Leandro V. Locsin |
| Floor Area | Approximately 200,000 m² (2.15 million sq ft) |
| Rooms | 1,788 |
| Bathrooms | 257 |
| Owner | Sultan Hassanal Bolkiah |
Can You Visit It?
Public access to Istana Nurul Iman is very limited. The palace opens its doors during the annual Hari Raya celebrations, when thousands of visitors are welcomed by the Sultan and the royal family. Outside these special occasions, the palace is not open for public tours because it continues to serve as the official residence of the Sultan of Brunei.
Travel Tip: If you plan to visit Brunei during Hari Raya, check the official celebration dates in advance, as public access is only available for a few days each year.
Why Is Istana Nurul Iman So Famous?
Its record-breaking size is only part of the story. The palace also symbolises Brunei’s royal heritage and remains an active centre of government and national ceremonies. Unlike many historic palaces that mainly function as museums today, Istana Nurul Iman continues to serve as a working royal residence, which makes it unique among the world’s largest homes.
Sources for Istana Nurul Iman: Details about the palace’s size, history, and official use are based on information published by the Government of Brunei Darussalam and widely recognised architectural and reference sources. These sources consistently identify the palace as the world’s largest residential palace by total floor area.
2. Royal Palace of Madrid (Spain)
Floor Area: Approximately 135,000 m² (1.45 million sq ft)
The Royal Palace of Madrid ranks as the second biggest house in the world by total floor area and is the largest royal palace in Europe. Located in the heart of Spain’s capital, it has served as a symbol of the Spanish monarchy for centuries and remains one of the country’s most treasured landmarks.
Although it’s the official residence of the Spanish royal family, the monarch doesn’t actually live here on a permanent basis. Instead, the palace is used mainly for important state ceremonies, official receptions, royal banquets, and diplomatic events throughout the year.
Construction began in 1738, after the original Alcázar of Madrid was destroyed by fire, and the palace was finally completed in 1764. It showcases a magnificent blend of Baroque and Classical architecture, with a grand design, luxurious interiors, and priceless art collections that make it one of Europe’s most visited royal landmarks.
Inside, the palace contains over 3,400 rooms, including royal apartments, ceremonial halls, libraries, armouries, and museums. Visitors can admire elegant marble staircases, beautifully painted ceilings, and some of Spain’s finest collections of art, furniture, clocks, and historical weapons, all under one roof.
Quick Facts
| Feature | Details |
| Location | Madrid, Spain |
| Completed | 1764 |
| Architectural Style | Baroque and Classical |
| Floor Area | Approximately 135,000 m² (1.45 million sq ft) |
| Rooms | More than 3,400 |
| Owner | Spanish State |
| Official Use | State ceremonies and royal events |
Can You Visit It?
Yes. The Royal Palace of Madrid is open to visitors throughout most of the year, and guests can explore the magnificent State Rooms, the Royal Armoury, the Royal Kitchen, and beautifully decorated ceremonial halls. Although it continues to host official royal events, large parts of the palace remain open whenever state ceremonies aren’t taking place.
Travel Tip: Visit early in the morning on weekdays for a quieter experience. Booking tickets online in advance can help you avoid long queues during the busy tourist season.
3. Buckingham Palace (United Kingdom)
Floor Area: Approximately 77,000 m² (828,000 sq ft)
Few buildings are as instantly recognisable as Buckingham Palace. As the official London residence of the British monarch, it’s one of the world’s most famous royal homes and ranks comfortably among the biggest houses in the world.
Originally built as Buckingham House in 1703, it was transformed into a full royal palace during the 19th century. Today, it serves as the administrative headquarters of the British monarchy while also hosting state banquets, diplomatic receptions, investiture ceremonies, and official national celebrations.
Its elegant Neoclassical architecture, iconic balcony, and centuries of royal tradition attract millions of visitors to London every year.
The palace contains 775 rooms in total, including 19 State Rooms, 52 royal and guest bedrooms, 188 staff bedrooms, 92 offices, and 78 bathrooms. The surrounding gardens cover around 39 acres, providing a genuinely peaceful retreat right in the centre of London.
Buckingham Palace is much more than a royal home; it’s one of Britain’s most important national landmarks and has been the setting for coronations, jubilees, royal weddings, and countless historic events. Its instantly recognisable façade has become a symbol of the British monarchy around the world.
Quick Facts
| Feature | Details |
| Location | London, England |
| Original Completion | 1703 |
| Architectural Style | Neoclassical |
| Floor Area | Approximately 77,000 m² (828,000 sq ft) |
| Rooms | 775 |
| Owner | British Crown |
| Official Use | Residence of the British monarch |
Can You Visit It?
Yes, but only during selected periods of the year. Visitors can tour the magnificent State Rooms during the Summer Opening, when the monarch is traditionally away from London. The famous Changing of the Guard ceremony also takes place just outside the palace and remains one of London’s most popular free attractions.
4. Antilia (India)
Floor Area: Approximately 37,000 m² (400,000 sq ft)
Unlike the royal palaces on this list, Antilia is the largest private house in the world. Located in Mumbai, India, this extraordinary skyscraper-style mansion is owned by billionaire businessman Mukesh Ambani and his family, and it has become one of the most talked-about private residences on the planet.
Completed in 2010, Antilia rises 27 storeys above one of Mumbai’s most exclusive neighbourhoods. Although it has fewer rooms than many of the historic palaces on this list, its enormous floor area and ultra-modern design make it one of the most remarkable private homes ever built.
Designed by the American architectural firm Perkins&Will, Antilia combines contemporary architecture with advanced engineering. Every level of the building has a different layout, creating a genuinely unique living space packed with luxury features throughout.Antilia stands apart because it’s the world’s largest privately owned residence built for a single family.
Some of its most impressive amenities include multiple swimming pools, a private cinema, a ballroom, a wellness spa, and a fitness centre. The building also features hanging gardens, multiple helicopter landing areas, parking for hundreds of vehicles, and dedicated staff accommodation. On top of all this, the structure is engineered to withstand powerful earthquakes and incorporates advanced environmental and energy-efficient technologies.
Quick Facts
| Feature | Details |
| Location | Mumbai, India |
| Completed | 2010 |
| Architectural Style | Contemporary |
| Floor Area | Approximately 37,000 m² (400,000 sq ft) |
| Height | 27 storeys |
| Owner | Mukesh Ambani |
Can You Visit It?
No. Antilia is a private residence and is not open to visitors. While tourists often stop to photograph the exterior from public areas nearby, entry is strictly restricted to the Ambani family, invited guests, and authorised staff.
Travel Tip: If you’re exploring Mumbai, you can view Antilia from nearby public roads. Please respect local regulations and the privacy of the residents while doing so.
5. Biltmore Estate (United States)
Floor Area: Approximately 16,600 m² (178,000 sq ft)
The Biltmore Estate is the largest privately owned home in the United States and ranks comfortably among the biggest houses in the world. Located in Asheville, North Carolina, this magnificent mansion was built by George Washington Vanderbilt II, a member of the famous Vanderbilt family.
Completed in 1895, Biltmore Estate was designed by renowned architect Richard Morris Hunt in the elegant French Renaissance Châteauesque style. Unlike many of the royal palaces on this list, Biltmore was created purely as a luxurious family home and country retreat.
The mansion features 250 rooms, including 35 bedrooms, 43 bathrooms, and 65 fireplaces. It also houses an impressive library with around 10,000 books, a grand banquet hall with a seven-storey ceiling, an indoor swimming pool, and one of America’s first residential bowling alleys.
The estate originally covered approximately 125,000 acres. Although much of that land has since been sold or donated, today’s estate still spans more than 8,000 acres, including formal gardens, walking trails, farmland, forests, a winery, and luxury accommodation. More than a century after its completion, Biltmore Estate remains one of America’s most visited historic homes and a genuine masterpiece of Gilded Age architecture.
Quick Facts
| Feature | Details |
| Location | Asheville, North Carolina, USA |
| Completed | 1895 |
| Architect | Richard Morris Hunt |
| Architectural Style | Châteauesque |
| Floor Area | Approximately 16,600 m² (178,000 sq ft) |
| Rooms | 250 |
| Owner | The Biltmore Company |
Can You Visit It?
Yes. Biltmore Estate is open to visitors throughout the year, and guests can tour the mansion, explore the award-winning gardens designed by Frederick Law Olmsted, visit the winery, and enjoy seasonal events held across the estate. Both self-guided and guided tours are available depending on your preference.
Travel Tip: Plan to spend at least half a day at Biltmore Estate. The mansion, gardens, winery, and surrounding grounds are extensive, and many visitors choose to stay overnight to experience everything the estate offers.
Why Is Biltmore Estate So Famous?
Biltmore Estate is famous for being America’s largest home and one of the finest examples of Gilded Age architecture anywhere in the country. Its beautifully preserved interiors, landscaped gardens, and rich history continue to attract visitors from around the world year after year.
6. Lakshmi Vilas Palace (India)
Floor Area: Approximately 15,000 m² (161,000 sq ft)
The Lakshmi Vilas Palace in Vadodara, Gujarat, is one of India’s grandest royal residences and ranks among the largest houses in the world. Completed in 1890, the palace was built for Maharaja Sayajirao Gaekwad III, one of India’s most progressive rulers, and it remains closely tied to the Gaekwad family to this day.
Designed by British architect Major Charles Mant, the palace blends Indo-Saracenic architecture with elements of Hindu, Islamic, and European design, creating a genuinely distinctive architectural style. The palace is often described as being around four times larger than Buckingham Palace, which highlights just how remarkable its scale and royal grandeur really are.
Its lavish interiors include stained-glass windows, marble staircases, intricate mosaics, elegant courtyards, and richly decorated reception halls. The surrounding palace grounds also feature museums, landscaped gardens, and one of the oldest private golf courses in India. Unlike many historic royal residences, Lakshmi Vilas Palace continues to be associated with the Gaekwad royal family while still welcoming visitors to selected areas.
Quick Facts
| Feature | Details |
| Location | Vadodara, Gujarat, India |
| Completed | 1890 |
| Architect | Major Charles Mant |
| Architectural Style | Indo-Saracenic |
| Floor Area | Approximately 15,000 m² (161,000 sq ft) |
| Original Owner | Maharaja Sayajirao Gaekwad III |
| Current Owner | Gaekwad Royal Family |
Can You Visit It?
Yes. Parts of Lakshmi Vilas Palace are open to visitors, including the museum, gardens, and selected sections of the palace itself. Some private areas remain closed, since members of the Gaekwad royal family still own and use portions of the property.
Why Is Lakshmi Vilas Palace So Famous?
The palace is celebrated for its unique architectural style, royal heritage, and artistic interiors. It remains one of India’s finest examples of 19th-century palace architecture and reflects the wealth and cultural vision of the Gaekwad dynasty at its peak.
7. Hearst Castle (United States)
Floor Area: Approximately 8,300 m² (90,000 sq ft)
Perched high above California’s Central Coast, Hearst Castle is one of America’s most iconic historic homes. Built for newspaper publisher William Randolph Hearst, it combines luxury living with world-class art, architecture, and genuinely breathtaking scenery.
Construction began in 1919 under the direction of celebrated architect Julia Morgan, the first woman licensed as an architect in California. Over the following decades, the estate evolved into an extraordinary hilltop retreat featuring lavish guest houses, magnificent gardens, fountains, terraces, and priceless works of art collected from around the world.
The main residence, known as Casa Grande, contains 115 rooms, while the wider estate includes several guest houses, making the overall property much larger than the central mansion alone. Hearst Castle is also famous for its spectacular Neptune Pool and Roman Pool, both widely considered masterpieces of architectural design in their own right.
Hearst Castle is famous for its stunning architecture, priceless art collection, and dramatic hilltop location overlooking the Pacific Ocean. It has appeared in numerous documentaries, books, and films over the years, which has helped make it one of America’s most recognised historic estates.
Quick Facts
| Feature | Details |
| Location | San Simeon, California, USA |
| Construction Began | 1919 |
| Architect | Julia Morgan |
| Architectural Style | Mediterranean Revival |
| Floor Area | Approximately 8,300 m² (90,000 sq ft) |
| Main House Rooms | 115 |
| Owner | State of California |
Can You Visit It?
Yes. Hearst Castle is open to the public through a variety of guided tours that showcase its luxurious rooms, famous swimming pools, beautiful gardens, and remarkable art collection. Different tour options highlight different areas of the estate, allowing visitors to choose an experience that matches their particular interests.
House vs Mansion vs Palace: What’s the Difference?
These three terms are often used interchangeably, but each one actually carries a distinct meaning that affects how properties get ranked and compared.
| Type | Meaning |
| House | A residential building designed for people to live in. It can be small or extremely large. |
| Mansion | A very large and luxurious private house, usually owned by an individual or family. |
| Palace | A grand residence built for royalty, heads of state, or other official leaders. Palaces are often used for ceremonial and government functions as well as residential purposes. |
This distinction explains why Antilia is recognised as the world’s largest private house, while Istana Nurul Iman is recognised as the world’s largest residential palace; they’re simply competing in different categories.
Which Is Bigger: Antilia or Biltmore Estate?
Antilia and Biltmore Estate are two of the world’s most famous luxury homes, but they differ significantly in both size and purpose, which makes them an interesting direct comparison.
Antilia has an estimated floor area of 37,000 square metres (400,000 square feet), making it more than twice the size of Biltmore Estate, which covers approximately 16,600 square metres (178,000 square feet). However, Biltmore Estate sits on a much larger overall property. The estate includes more than 8,000 acres of gardens, forests, farmland, and walking trails, while Antilia occupies a relatively small urban site within Mumbai.
In short:
- Largest by floor area: Antilia
- Largest by land area: Biltmore Estate
This comparison shows exactly why it’s important to distinguish between building size and property size whenever you’re comparing famous homes against one another.
Can You Visit These Houses?
The table below provides a quick overview of public access across the seven biggest houses in the world.
| House | Country | Open to Visitors? |
| Istana Nurul Iman | Brunei | Limited (Hari Raya celebrations only) |
| Royal Palace of Madrid | Spain | Yes |
| Buckingham Palace | United Kingdom | Yes (seasonal opening) |
| Antilia | India | No |
| Biltmore Estate | United States | Yes |
| Lakshmi Vilas Palace | India | Partial access |
| Hearst Castle | United States | Yes |
As you can see, many of the world’s largest houses are open to visitors for at least part of the year. However, active royal residences and privately owned homes generally come with limited or no public access at all.
Frequently Asked Questions
What is the biggest house in the world?
The biggest house in the world is Istana Nurul Iman in Brunei. It covers approximately 200,000 square metres (2.15 million square feet) and serves as the official residence of Sultan Hassanal Bolkiah. The palace contains 1,788 rooms, 257 bathrooms, five swimming pools, and a banquet hall that can host around 5,000 guests.
What is the biggest private house in the world?
The biggest private house in the world is Antilia in Mumbai, India. Owned by billionaire Mukesh Ambani, the 27-storey residence covers approximately 37,000 square metres (400,000 square feet) and features luxury amenities such as private cinemas, swimming pools, wellness facilities, and multiple helicopter landing areas.
What is the biggest house in the United States?
The Biltmore Estate in Asheville, North Carolina, is the largest privately owned home in the United States. Built by George Washington Vanderbilt II, the mansion has 250 rooms and covers approximately 16,600 square metres (178,000 square feet).
Who owns the biggest house in the world?
The biggest house in the world, Istana Nurul Iman, is owned by Sultan Hassanal Bolkiah, the Sultan of Brunei. Completed in 1984, the palace serves as both his official residence and the centre for state ceremonies, diplomatic meetings, and national events. As the head of Brunei’s royal family, the Sultan uses the palace for both private living and official duties.
How many rooms does the biggest house in the world have?
The world’s biggest house, Istana Nurul Iman, has 1,788 rooms, making it the largest residential palace by total floor area. It also includes 257 bathrooms, five swimming pools, a banquet hall that can accommodate around 5,000 guests, a private mosque for approximately 1,500 worshippers, and air-conditioned stables for the Sultan’s polo horses. These features reflect the palace’s dual role as a royal residence and an official venue for state functions.
Why is Antilia not ranked number one?
Although Antilia is often called the world’s largest private house, it’s actually much smaller than several royal palaces when measured by total floor area. This article ranks houses using total floor area, which places Istana Nurul Iman first overall.
Can you visit the biggest houses in the world?
Some of them are open to visitors, while others remain strictly private. For example:
- Royal Palace of Madrid – Open to visitors
- Buckingham Palace – Open during selected months
- Biltmore Estate – Open year-round
- Hearst Castle – Guided tours available
- Antilia – Not open to the public
- Istana Nurul Iman – Limited access during Hari Raya celebrations
Which country has the biggest house?
Brunei is home to the biggest house in the world, Istana Nurul Iman. Spain, the United Kingdom, India, and the United States also have some of the world’s largest residential buildings on this list.
How are the biggest houses measured?
The most reliable way to compare very large houses is by total floor area, also known as gross floor area. This measures the total usable space inside the building and allows for fair comparisons between private homes and royal residences alike.
Key Takeaways
– Istana Nurul Iman is the world’s biggest house.
– Antilia is the largest private house.
– Biltmore Estate is America’s biggest home.
– Most royal palaces are open to visitors, while private homes generally are not.
Final Thoughts
Researching the world’s biggest houses quickly showed me why so many articles disagree. The rankings often change because different sources use different measurements or separate private mansions from royal palaces without explaining the difference.
By using total floor area as a consistent standard and comparing information from reliable sources, this guide provides a clearer and fairer ranking. Based on that approach, Istana Nurul Iman remains the world’s biggest house, while Antilia holds the title of the largest private residence.
Beyond their record-breaking size, these remarkable homes showcase the history, culture, engineering, and ambition of the people who built them. Whether you came here for a quick answer or to explore some of the world’s most extraordinary residences, I hope this guide gives you accurate information you can trust.
