The challenges faced by modular housing firms in the UK can be attributed to a variety of factors, which may include:

1. Market Familiarity and Consumer Perception: Traditional methods of construction are deeply ingrained in the UK’s housing sector. Consumers and investors might be more familiar with and trust conventional building methods over modular housing, which is a relatively new concept. This unfamiliarity can lead to scepticism and slow adoption.

2. Regulatory and Planning Challenges: The UK’s planning and building regulations might not be fully adapted to modular construction. These regulations, developed around traditional construction methods, could pose hurdles for modular housing projects, such as difficulties in obtaining approvals or meeting specific building codes.

3. Initial Investment and Scale: Modular housing requires significant upfront investment in factories and technology. Achieving economies of scale is crucial for making modular housing cost-effective, but reaching this scale can be challenging without sufficient demand or investment.

4. Supply Chain and Logistics: Modular construction relies on a robust supply chain and efficient logistics for transporting modules to sites. Any disruptions in the supply chain or challenges in transportation (like navigating narrow UK roads) can significantly impact project timelines and costs.

5. Design Limitations and Customization: While modular homes offer faster construction and potentially lower costs, there may be perceptions about limitations in design flexibility and customization compared to traditional homes. This perception could affect consumer demand.

6. Economic and Financial Factors: Economic uncertainties, such as those related to Brexit or the global economy, can impact investment and development decisions. Additionally, traditional lenders might be more hesitant to finance modular construction projects due to their unfamiliarity with the risks and rewards.

7. Skilled Labor and Expertise: The modular construction industry requires a different set of skills compared to traditional construction. There might be a shortage of skilled labor experienced in modular construction techniques, which can hinder the growth of this sector.

8. Sustainability and Quality Concerns: While modular homes can be more sustainable and of higher quality, there may still be public concerns or misconceptions about their durability and environmental impact. Overcoming these perceptions is crucial for wider acceptance.

Each of these factors contributes to the challenges faced by modular housing firms in the UK, and addressing them requires a concerted effort from industry players, regulators, and other stakeholders.