Overview of the O’Sullivan House

The O’Sullivan house, also known as the Miller O’Sullivan or simply O’Sullivans, is a distinctive type of system-built property that emerged in the UK during the 1940s and 1950s. Designed and manufactured by E O’Sullivan, these homes were part of a post-war effort to address housing shortages. With only 100 units built, they are relatively rare and hold a unique place in British architectural history.

Historical Context and Manufacturing Details

Period of Construction

The O’Sullivan houses were constructed between the late 1940s and early 1950s. This period was marked by a significant demand for quick and affordable housing solutions due to the post-World War II housing crisis. The government and private developers turned to system-built properties to meet this demand efficiently.

Manufacturer and Designer

Both the design and manufacturing of these homes were overseen by E O’Sullivan, a notable figure in the construction industry during that era. E O’Sullivan’s approach combined innovative building techniques with practical design elements to create homes that were both functional and economical.

Typical Locations

These properties are typically found in suburban areas, often in regions that experienced rapid development during the post-war period. They are most commonly located in the Midlands and the North of England, where the need for new housing was particularly acute.

Architectural Characteristics

General Features

O’Sullivan houses are two-storey semi-detached homes, easily identifiable by their medium pitch hipped or gable roofs covered with concrete tiles. The external walls are rendered throughout, providing a uniform and somewhat austere appearance. One of the most distinctive features is the square fronted single-storey flat-roofed bay on the front elevation. In some cases, the flat roof of the bay extends as a canopy over the front door.

Construction Details

Substructure

The substructure of an O’Sullivan house includes concrete strip footings, concrete under-building, and a concrete slab. Honeycomb sleeper walls and a damp-proof course (DPC) are also integral parts of the foundation.

External Walls

The external walls are rendered and consist of 11-inch concrete cavity walls with a 2-inch cavity. Mild steel (MS) wall ties are used to secure the structure. Precast (PC) slip blocks seal the cavity at window and door openings, and reinforced concrete (RC) lintels are placed over these openings. A lead damp-proof membrane (DPM) and timber wall plates complete the wall construction.

Separating Walls

Separating walls between properties are constructed with 11-inch concrete cavity walls up to the eaves level and 9-inch brickwork in the roof space. Behind the fireplace, a 9-inch concrete wall is used.

Partitions

Internal partitions are made from 4.5-inch concrete blocks bonded to the external walls and tied with MS hoops for added stability.

Floors

The ground floor consists of timber boarding on timber joists, which rest on timber wall plates supported by concrete sleeper walls. The first floor follows a similar construction method with timber boarding on timber joists.

Ceilings

Ceilings are typically made of plasterboard, providing a smooth and easily maintainable surface.

Roof

The roof structure includes timber rafters and purlins, covered with concrete tiles. The chimney is constructed from 4.5-inch concrete blocks on the ground floor and 4.5-inch brickwork above.

Variants

Some O’Sullivan houses feature variations such as 11-inch precast reinforced concrete (PRC) lintels, continuous RC courses at eaves level, staggered air vents in both leafs, and slate or asbestos cement liners to door and window reveals. Additionally, some floors are constructed with 3-inch by 1.5-inch pressed steel joists and concrete.

Typical Hazards and Risks

Structural Issues

One of the most common issues with O’Sullivan houses is vertical cracking in the external walls between ground and first-floor openings. This can be a sign of structural movement or settlement, which may require professional assessment and remediation.

Damp and Moisture

Due to the age of these properties, damp and moisture ingress can be a significant concern. The lead DPM and concrete cavity walls were advanced for their time but may have deteriorated over the decades, leading to potential damp issues.

Asbestos

Some variants of the O’Sullivan house include asbestos cement liners in door and window reveals. Asbestos was commonly used in construction during the mid-20th century but is now known to pose serious health risks. Proper identification and removal by licensed professionals are essential.

Thermal Efficiency

The original construction methods and materials used in O’Sullivan houses may not meet modern thermal efficiency standards. Upgrading insulation and installing energy-efficient windows and doors can help improve the property’s energy performance.

Defective Premises Act Considerations

The Defective Premises Act 1972 imposes a duty on builders, developers, and landlords to ensure that properties are constructed and maintained to a reasonable standard. While the O’Sullivan houses were built to the standards of their time, they may not meet current building regulations. Potential buyers should be aware of this and consider commissioning a thorough survey to identify any defects or areas requiring improvement.

Inspection Guide for Surveyors

External Inspection

Walls

• Look for vertical cracking between ground and first-floor openings.
• Check the condition of the render and look for signs of spalling or detachment.
• Inspect the lead DPM for any signs of deterioration or failure.

Roof

• Examine the concrete tiles for any damage or missing pieces.
• Check the condition of the timber rafters and purlins for signs of rot or insect infestation.
• Inspect the chimney for structural integrity and any signs of cracking or leaning.

Windows and Doors

• Look for signs of moisture ingress around window and door reveals.
• Check for the presence of asbestos cement liners and ensure they are in good condition or have been safely removed.

Internal Inspection

Floors

• Inspect the timber boarding and joists for signs of rot, warping, or insect damage.
• Check for any unevenness or sagging in the floors, which could indicate structural issues.

Walls and Partitions

• Look for signs of cracking or movement in internal partitions.
• Check the condition of the plasterboard ceilings for any signs of water damage or sagging.

Damp and Moisture

• Use a moisture meter to check for dampness in walls, floors, and ceilings.
• Look for signs of mould or mildew, which could indicate ongoing moisture issues.

Utilities and Services

• Inspect the electrical system for compliance with current safety standards.
• Check the plumbing for any signs of leaks or corrosion.
• Ensure that the heating system is in good working order and meets modern efficiency standards.

Typical Defects and Maintenance Tips

Common Defects

• Vertical Cracking: As mentioned earlier, vertical cracking in external walls is a common issue. Regular monitoring and professional assessment are recommended.
• Damp and Moisture: Address any signs of dampness promptly to prevent further damage. Consider upgrading the DPM and improving ventilation.
• Asbestos: If asbestos is present, ensure it is managed safely and consider professional removal.
• Thermal Efficiency: Improve insulation and consider installing double-glazed windows to enhance energy efficiency.

Maintenance Tips

• Regular Inspections: Conduct regular inspections to identify and address any issues early.
• Professional Assessments: Engage professional surveyors and contractors for any significant repairs or upgrades.
• Preventative Measures: Implement preventative measures such as improved drainage and ventilation to protect the property from damp and structural issues.

Conclusion

The O’Sullivan house represents a unique chapter in the history of British housing. While these properties have their quirks and potential issues, they also offer a distinctive charm and historical significance. For home buyers and investors, understanding the construction details, typical hazards, and maintenance requirements is crucial. By conducting thorough inspections and addressing any issues promptly, you can ensure that an O’Sullivan house remains a valuable and enjoyable home for years to come.

At Flettons, we’re committed to safeguarding your investment. When considering a property purchase, trust our seasoned expertise to reveal any hidden threats. For a thorough building survey, get your instant quote through our quote calculator or reach out directly at 0203 691 0451. Your home’s safety is our top priority.