Technical Roofing Services for Complex Commercial and High-Rise Projects

Our technical roofing specialists provide comprehensive support for complex roofing projects, encompassing everything from detailed design and compliance to access planning and maintenance schedules.

We work alongside building managers, surveyors, and facilities teams to help them make informed decisions based on accurate calculations, risk assessments, and long-term strategies tailored to modern and heritage buildings.

It doesn’t matter if your building is located on a city centre street, near a river, or at height, our team develops access-led solutions that enable compliant, practical, and cost-effective roofing strategies.

Roof Drainage Design and Part H of the Building Regulations

 An effective roof drainage design isn’t just a technical necessity; it’s safeguarding for your entire building, and a legal requirement under part H of the Building Regulations.

Poor drainage planning or neglected outlets can result in standing water, leaks, structural deterioration, and significant repair costs down the line. For commercial properties, especially those with extensive flat roofs, ensuring robust water management is critical to maintaining building integrity and protecting valuable assets.

At Building Transformation, we approach roof drainage as an integrated part of a building’s performance. Our technical roofing specialists conduct precise calculations and design reviews to ensure every aspect of your drainage system works in harmony with the roof’s shape, size, and purpose.

We carry out detailed roof drainage calculations to ensure rainwater is managed efficiently, especially on flat and large commercial roofs. Our process involves:

  • Rainfall intensity and catchment area analysis
  • Siphonic or gravity drainage system recommendations
  • Outlet positioning and sizing
  • tapered insulation design
  • Compliance with BS EN 12056-3:2000

This means your drainage meets regulatory standards and performs reliably under heavy rainfall conditions. We can also offer rainwater outlet testing to check flow capacity and identify potential restrictions that could compromise the system.

You might also benefit from reading: Commercial Rainwater System Repairs

Condensation Risk Analysis and part C of the Building Regulations

Condensation may be invisible at first, but it’s one of the most damaging threats to a commercial roofing system. It doesn’t just cause staining or surface damp; it can saturate insulation, reduce thermal performance, corrode metal fixings, and decay timber structures.

Furthermore, managing condensation is a legal requirement under BS 5250 and part C of the Building Regulations.

Condensation forms when warm, moisture-laden air meets colder surfaces inside the roof build-up, causing water vapour to turn into liquid droplets. This can occur in any type of roof, including flat, pitched, single-ply, metal, or complex architectural roofs such as domes and skylights. For commercial properties, this poses significant financial and operational risks:

  • Increased heating costs due to wet, ineffective insulation
  • Accelerated material degradation shortens the roof’s lifespan
  • Health and safety hazards like mould growth and poor indoor air quality
  • Insurance or compliance issues if damage is extensive or persistent

High-rise and difficult-to-access buildings are particularly vulnerable because inspection and repair can be more complex and costly. That’s why a proactive approach to moisture management is critical.

At Building Transformation, we conduct condensation risk assessments as part of our wider technical roofing solutions. If issues are detected, we’ll recommend precise interventions. All of which comply with UK Building Regulations and industry best practice, ensuring robust protection for your building envelope.

Condensation risk analysis is a crucial part of designing, refurbishing, or maintaining commercial roofs. We link these findings into your roof condition surveys, thermal performance assessments, and broader refurbishment plans, so you get a cohesive strategy for protecting your asset and extending its service life.

Thermal Performance and Insulation Calculations

In commercial and high-rise construction, a roof’s thermal performance isn’t simply about comfort – it’s about compliance to part L of building regulations, sustainability, and operational efficiency.

We can evaluate and enhance thermal roof performance through precise technical assessments and innovative refurbishment solutions, all while navigating the unique challenges posed by tall and difficult-to-access structures.

We assess roof thermal performance to ensure your system meets energy efficiency targets and complies with regulatory requirements. This includes:

  • Roof thermal modelling and U-value calculations
  • Recommendations for insulation type and thickness
  • Access-led installation planning

Some commercial roofs are still operating with outdated insulation materials or insufficient thicknesses, which fail to meet modern energy efficiency requirements.

Our thermal upgrade services include:

  • Removal of saturated or degraded insulation
  • Installation of high-performance insulation systems, tailored for flat, pitched, or complex roof geometries
  • Integration with liquid-applied waterproofing, Modified Bitumen membrane or single-ply overlays for seamless protection
  • Solutions designed for modern and heritage properties alike

These enhancements not only help our clients to reduce their heating and cooling costs but also support their obligations under tightening energy regulations, helping commercial properties achieve better EPC ratings and sustainability credentials.

In buildings where access is limited or disruptive, our team creates bespoke strategies using MEWPs, rope access, safety line systems or temporary anchors to install insulation upgrades with minimal disruption to tenants or operations.

Book a Technical Roof Survey or Consultation

Roof Drainage Compliance

All roof drainage systems must comply with UK building regulations. We provide compliance assessments and make practical recommendations for system upgrades.

Our service includes:

  • Drainage design reviews
  • Capacity calculations using BS EN 12056-3:2000
  • Review of outlet locations and numbers
  • Guidance on siphonic vs gravity systems

When required, we can work alongside your architect, consultant, or facilities manager to develop compliant solutions for refurbishment or new build scenarios.

Planned Preventive Maintenance Schedules (PPM)

Regular ongoing scheduled maintenance prevents major issues from occurring and can save you money in the long run. Unfortunately, often hard to access areas get neglected and issues build up which are not identified until they become urgent and costly.

A structured PPM strategy reduces emergency repairs, protects internal assets, and extends the service life of your roof.

Although we can implement the practises laid out by the Building O&M Manuals, we often find there is limited or no information regarding ongoing maintenance. In this case we can develop a specific maintenance plan for the building, tailored to your budget and priorities, that covers:

  • Regular inspections and condition reporting
  • Forecasted repair budgets
  • Cleaning, resealing, and preventative treatments
  • Seasonal checks for drainage and thermal performance

This proactive approach can prevent revenue loss from roof leaks or unplanned downtime, especially in hotels, offices, and healthcare buildings.

You might like to read: The Importance of Roof Maintenance

Roof Safety System Design and Installation

We ensure safe working access on every project by designing and installing custom roof safety systems.

As an IRATA International Member, our team follow strict RAMS protocols and access strategies tailored to the complexity and location of the site. Our services include:

  • Fixed and temporary roof safety systems
  • Rescue strategies for working at height
  • Safety compliance documentation and audits

As accredited members of IRATA and ISO 9001 certified, we prioritise a safety-first culture which gives our partners complete peace of mind during every stage of your commercial roofing project.

Want to see how technical roofing insights can transform your project outcomes? Book a consultation or roof survey and let our team create a safe, efficient, and compliant plan tailored to your building.

Book a Technical Roof Survey or Consultation