Loft Conversion

Flat-roof dormer construction: framing sequence (trimmer joists, structural header, dormer rafters), Code 4/5 lead flashings at back gutter and stepped cheeks, cheek cladding options (lead, tile hanging, render, zinc), PD planning rules (no front dormers facing highway), warm vs cold flat roof waterproofing

Hip to gable conversion: converting sloped hip end to vertical gable, PD on end-of-terrace/detached (not semi where hip remains), structural gable wall sequence, ridge extension, combined with rear dormer for maximum space, cost premium £5k–£15k, party wall triggers

Loft conversion building control: Full Plans vs Building Notice (full plans recommended), 7 inspection stages, Building Safety Act 2022 (Registered Building Inspectors), regularisation for missing certificates, completion certificate importance for remortgage/sale

Loft conversion Building Regulations overview: Parts A (structure), B (fire), C (damp), F (ventilation), K (stairs/guarding), L (insulation), and P (electrical) — what each covers, full plans vs building notice, and completion certificate importance

Loft conversion electrical: Part P notifiable new circuit from consumer unit, RCBO protection, Grade D LD2 smoke alarm layout per BS 5839-6:2019, lighting and heating options, consumer unit capacity check, NICEIC/NAPIT self-certification routes

Loft conversion fire escape: Part B protected staircase (FD30 self-closing fire doors, 12.5mm plasterboard enclosure) vs escape window (0.33m² min clear opening, 450mm × 450mm min, ≤1100mm from floor), mains-wired interlinked Grade D1 alarms, and sprinkler alternative

Loft conversion floor structure: why existing ceiling joists fail (deflection limits L/360), sister joist method vs replacement, C24 joist sizing table (3.5m–5.5m spans), steel beam alternatives, Part E acoustic targets (45dB DnTw airborne, 62dB L'nTw impact), Building Control inspection stages

Loft conversion insulation: Part L1B 0.18 W/m²K target for warm pitched roof, PIR between-rafter + below/over-rafter options, vapour control layer placement, breather membrane requirement, avoiding spray foam, and airtightness obligations

Loft conversion permitted development rights: 40m³ terraced / 50m³ detached volume limits, rear dormers, hip-to-gable, front dormer prohibition, rooflight conditions, designated area restrictions, and Lawful Development Certificates

Loft conversion en suite plumbing: combi vs unvented hot water options, gravity drainage minimum falls (1:45 soil, 1:80 basin/shower), macerator restrictions (not sole WC), soil stack extension, AAV placement per AD H, water pressure check at loft level

Loft conversion structural design: new floor joist sizing (47×200mm C16), steel beam specification by a Chartered Structural Engineer, purlin support/removal options, ridge beam, padstones, trussed rafter complexity, and Party Wall Act triggers

Loft conversions and the Party Wall Act 1996: Section 2 trigger table for common activities (notching, beam bearing, tanking), 2-month notice period, surveyor appointment process, party wall award, flank wall vs party wall distinction, practical timeline impact

Loft stair Building Regs: AD K geometry (220mm max rise, 220mm min going, 2000mm headroom), alternating tread stair rules (42° max, 220mm wider tread), 1800mm headroom concession at stair edges, FD30S fire door requirement for 3-storey conversions, 100mm sphere baluster rule

Mansard roof conversion: 72° near-vertical rear slope design, why planning permission is almost always required (not PD), London terraced house build sequence, cost £60k–£100k, materials matching conditions, fire escape requirements from mansard floor

Velux vs dormer loft conversion: planning risk comparison, headroom-by-pitch table, cost ranges (Velux £20k–£35k vs dormer £35k–£55k), usable floor area comparison, GPDO 2015 Class A/B conditions, decision framework by roof pitch and budget