Introduction to the Hertsmere Special House

The Hertsmere Special house is a unique and intriguing property type that has piqued the interest of home buyers and investors alike. As an expert surveyor with extensive knowledge of system-built properties, I am here to provide you with a detailed and insightful guide on this particular house type. This article will cover everything from its history and construction to typical characteristics, potential hazards, and inspection tips. By the end of this guide, you will have a thorough understanding of the Hertsmere Special house and be well-equipped to make informed decisions when considering such a property.

Historical Background

Manufacturer and Designers

The Hertsmere Special house was manufactured by a consortium of builders and designers who were active during the post-war period in the UK. The exact names of the manufacturers and designers are not well-documented, but it is known that these houses were part of a broader effort to address the housing shortage in the mid-20th century.

Period Built

These houses were predominantly built between the late 1940s and the early 1960s. This period was marked by a significant demand for affordable and quickly constructed housing solutions, leading to the development of various system-built properties, including the Hertsmere Special.

Number Built

While the exact number of Hertsmere Special houses constructed is not precisely known, it is estimated that several thousand were built across various regions in the UK. These houses were primarily located in suburban areas, providing affordable housing options for families.

Alternative Names

The Hertsmere Special house does not have widely recognized alternative names. However, it is sometimes referred to by local names or nicknames based on the specific area where it was built.

Identification Characteristics

General Features

The Hertsmere Special house is typically a 2-storey semi-detached property. One of its most distinctive features is the medium pitch hipped roof covered with tiles. The external walls are characterized by exposed Precast Reinforced Concrete (PRC) columns and beams, which are infilled with Precast Concrete (PC) panels.

External Appearance

The external appearance of the Hertsmere Special house is quite distinctive due to its exposed PRC columns and beams. These structural elements are often visible and give the house a unique architectural style. The infilled PC panels between the columns and beams are usually rendered or painted, adding to the overall aesthetic.

Construction Details

Roof

The roof of the Hertsmere Special house is a medium pitch hipped roof covered with tiles. This type of roof design is relatively common in semi-detached houses from the mid-20th century and provides good drainage and durability.

Walls

The external walls are constructed using exposed PRC columns and beams, which are infilled with PC panels. This construction method was chosen for its speed and cost-effectiveness during the post-war housing boom.

Floors

The specific details of the ground and first floors are not well-documented. However, it is likely that the floors were constructed using standard methods of the time, such as suspended timber floors or concrete slabs.

Main Frame

The main frame of the Hertsmere Special house is composed of PRC columns and beams. This structural system provides the necessary support for the building and is a key feature of its design.

Ceilings

The ceilings in Hertsmere Special houses are typically constructed using standard plasterboard or lath and plaster methods. These materials were commonly used in mid-20th century construction.

Typical Defects and Hazards

Common Defects

1. Corrosion of Steel Reinforcement: One of the most common defects in Hertsmere Special houses is the corrosion of steel reinforcement within the PRC columns and beams. This can lead to structural weakening and potential safety hazards.

2. Carbonation of Concrete: Carbonation is a chemical process that occurs when carbon dioxide from the air penetrates the concrete and reacts with calcium hydroxide to form calcium carbonate. This can reduce the alkalinity of the concrete, leading to corrosion of the steel reinforcement.

3. Cracking and Spalling: Cracks can develop in the concrete due to thermal movement, shrinkage, or structural stress. Spalling, or the flaking off of concrete, can occur as a result of these cracks and the corrosion of steel reinforcement.

4. Water Ingress: Due to the construction methods used, Hertsmere Special houses can be prone to water ingress, particularly around the joints between the PRC columns and PC panels. This can lead to dampness and mould issues.

Potential Hazards

1. Structural Instability: The corrosion of steel reinforcement and carbonation of concrete can lead to significant structural instability. This is a serious concern and requires immediate attention if identified.

2. Health Risks: Water ingress and dampness can lead to the growth of mould, which can pose health risks to the occupants. It is essential to address any signs of dampness promptly.

3. Energy Efficiency: Due to the construction methods used, Hertsmere Special houses may not be as energy-efficient as modern homes. This can result in higher heating costs and a less comfortable living environment.

Defective Premises Act

The Hertsmere Special house is not specifically classified as defective under the Defective Premises Act. However, the potential structural issues and defects associated with this property type mean that it is essential to conduct thorough inspections and assessments before purchasing or investing in such a house.

Inspection Tips for Surveyors

Preliminary Assessment

1. Visual Inspection: Begin with a thorough visual inspection of the property. Look for any obvious signs of cracking, spalling, or water ingress. Pay particular attention to the joints between the PRC columns and PC panels.

2. Historical Records: Review any available historical records or previous survey reports for the property. This can provide valuable insights into past issues and repairs.

Detailed Inspection

1. Structural Assessment: Conduct a detailed structural assessment of the PRC columns and beams. Look for signs of corrosion, cracking, and spalling. Use non-destructive testing methods, such as ultrasonic testing, to assess the condition of the steel reinforcement.

2. Concrete Carbonation: Test the concrete for carbonation depth. This can be done using a phenolphthalein solution, which changes colour in the presence of alkaline concrete. Deeper carbonation indicates a higher risk of steel reinforcement corrosion.

3. Moisture Assessment: Check for signs of water ingress and dampness. Use moisture meters to assess the moisture levels in the walls and floors. Look for any signs of mould growth, which can indicate ongoing damp issues.

4. Roof Inspection: Inspect the roof for any signs of damage or wear. Check the condition of the tiles and the roof structure. Look for any signs of water ingress or leaks.

Reporting and Recommendations

1. Detailed Report: Provide a detailed report of your findings, including any identified defects and potential hazards. Use clear and concise language to explain the issues and their implications.

2. Repair Recommendations: Offer recommendations for necessary repairs and maintenance. This may include structural repairs, concrete remediation, and measures to address water ingress and dampness.

3. Cost Estimates: Provide cost estimates for the recommended repairs. This can help the buyer or investor make informed decisions about the property.

Conclusion

The Hertsmere Special house is a unique and historically significant property type that offers both opportunities and challenges for home buyers and investors. Understanding its construction, typical defects, and potential hazards is essential for making informed decisions. By conducting thorough inspections and assessments, you can ensure that you are fully aware of any issues and can take appropriate action to safeguard your investment.

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.

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