The pros, cons and costs of flat and pitched roofing for Surrey homeowners, from the experts at Surrey Roofing & Windows Ltd.
By Max, Surrey Roofing & Windows Ltd | April 2026
Whether you're building an extension, replacing an existing roof or considering your options for a problem area, the choice between flat and pitched roofing is one of the most common questions we get from Surrey homeowners. Here's our honest assessment.
Advantages: Superior water shedding, excellent lifespan (30-50+ years for clay), lower long-term maintenance, traditional aesthetics suited to most Surrey properties, better thermal performance in cold weather.
Disadvantages: Higher initial installation cost, requires more structural support, less usable space in the roof void if uninsulated.
Cost in Surrey: GBP 12,500-50,000 for a full pitched roof replacement depending on size and materials.
Advantages: Lower installation cost, ideal for extensions and outbuildings, can be used as accessible roof terrace, simpler construction on low-pitch areas.
Disadvantages: Shorter lifespan (15-25 years for GRP, 10-15 years for felt), requires regular inspection, more susceptible to ponding water if drainage poorly designed.
Cost in Surrey: GBP 80-120 per m2 for GRP fibreglass, which is the gold standard for domestic flat roofing.
For the main roof of a Surrey residential property, we almost always recommend a pitched system because the long-term performance and lower maintenance costs make it the better value over 30+ years. For extensions, garages, dormer cheeks and other ancillary elements, a quality GRP flat roof is an excellent choice.