Loft Conversion Specialists across the North West.

A loft conversion is the most cost-effective way to add a bedroom or a usable room to a standard UK semi-detached or detached house. The average cost per square metre is substantially lower than a ground-floor extension, and because you are building within the existing roof envelope, the disruption to the ground-floor living space is minimal. The work happens above your head, not around your kitchen.

We handle the full conversion scope: structural design, building regulations application, the roof alterations themselves (dormer formation, rafter reinforcement, Velux positioning), first-fix and second-fix carpentry, and the fitted finish. We do not subcontract the critical roof-line work to a separate roofer. It is done in-house.

Conversion types we build

The Velux conversion is the most straightforward and the most affordable. It keeps the existing roof profile intact and adds VELUX GGL or GGU conservation-spec rooflights to bring in light and headroom. Most semi-detached houses in the L, CH and WA postcode areas have enough ridge height for a usable Velux room without dormer addition.

Dormer conversions add a flat-roofed or cat-slide dormer to the rear slope to maximise floor area and headroom. The dormer structure is typically a timber-framed box covered in either EPDM rubber or GRP, clad in render or matching tile-hanging to the existing elevation. We form the structural opening and install the dormer in the same operation rather than in separate trades.

Hip-to-gable conversions suit the end-of-terrace and detached stock that has a hipped end. Rebuilding the hip as a vertical gable adds significant floor area and opens up a full dormer on what was the hip face. It requires a structural calculation for the gable wall and party wall agreement with the neighbour on terraced and semi-detached properties.

Planning and building regulations

Most Velux and rear dormer conversions fall within permitted development rights for residential properties in England. The PD envelope allows a rear dormer up to 40 cubic metres of additional roof space on a semi-detached house and 50 cubic metres on a detached house, provided the dormer does not sit above the ridge line or protrude beyond the original roof slope at the front.

Planning permission is required if the property is listed, sits in a conservation area (Chester city centre, parts of the Wirral coastal towns, and several Cheshire village centres all have restrictions), or if the conversion alters the front elevation visible from the highway. We handle the planning application if required. In Wales, PD rights differ from England and we apply under the separate Welsh Ministers regime.

Building Regulations approval is mandatory for all loft conversions regardless of planning status. The key Parts are Part A (structural), Part B (fire escape, which typically requires a 30-minute fire-rated enclosure around the new stair), Part K (stair pitch, guarding and headroom), and Part L (thermal performance of the new roof elements and dormer walls). We submit the full-plans application and handle Building Control inspection from foundation check to completion certificate.

Materials we run

New rafter sections go in as C24 graded timber sized to the structural engineer's specification. We do not upsize informally; the structural engineer certifies the correct section size for the span and the applied loading. Dormer flat roofs are Firestone EPDM or CURE IT GRP depending on complexity. VELUX windows go in as VELUX GGL or GGU double-glazed units with BBA certification, or as VELUX Conservation spec on listed and heritage-adjacent properties where the planning condition requires low-profile glazing.

Insulation goes in as either PIR board (Kingspan or Recticel) between and below rafters to achieve Part L compliance, or as spray-applied closed-cell foam where the rafter depth is shallow. In either case we hit the minimum 0.16 W/m2K U-value that Part L requires for a new converted roof slope.

What it costs

A Velux conversion with two rooflights, structural alterations, new stair, plasterboard finish and building regulations through to completion certificate typically runs between £18,000 and £28,000 on a standard semi across the L and CH postcode areas. A full rear dormer adds £8,000 to £14,000 to that depending on the dormer size and finish. A hip-to-gable conversion is priced on survey. We quote fixed-price after a structural assessment and site visit.

What we back it with

All loft conversion work carries a 10-year workmanship guarantee. The building regulations completion certificate issued at the end of the project is a transferable document that satisfies solicitors on any future property sale. VELUX windows carry a 10-year manufacturer guarantee on hardware and 20 years on the glazing unit. We register all manufacturer guarantees in the homeowner's name on the day we hand over.