Part 2 focuses on modern, contemporary dormers. Since the 1960s the dormer has evolved from a handcrafted element to an industrial prefab product that can be installed on the house in a single day. These examples show how material, form and construction method have changed.
Standard flat-roof dormer (1960s–1980s)
The most common dormer in terraced houses:
- Flat roof with slight fall to the rear, covered with bitumen
- Wood or aluminium frame with single or double glazing (later high-performance)
- Cheeks clad in trespa, timber or zinc
- Standard widths of about 1.5 to 3 metres
Wide and continuous dormers
For loft conversions that maximise headroom, a continuous dormer is often used:
- Width of 4 to sometimes 8 metres
- Multiple window frames side by side, possibly with French doors
- Steel lintel for extra structural support
- French balcony or roof terrace connection
Prefabricated dormers
Modern prefabricated dormers are assembled in the factory:
- Delivered complete including frame, glass, insulation and cladding
- Installed in a single day by crane
- High insulation values (U-value below 0.16 W/m²K)
- Smooth finish in trespa, keralit or aluminium
Architecturally distinctive dormers
In contemporary detached houses or considered renovations, creative versions appear:
- Shed dormer with steep or very low pitch
- Fully zinc or copper-clad dormer
- Dormer with timber cladding (Western Red Cedar, Accoya)
- Cantilevered dormer with a floating effect
Application
Modern dormers are often ordered through a specialist company that takes care of installation, finishing and planning permission. Lead times are typically 6 to 12 weeks.
Related terms
- Dormer
- Dormers
- Prefabricated construction
- French balcony
- Mono-pitch roof
Want to learn more about construction terms? Visit our knowledge base at fredsdiyplans.com.