Boarshurst Lofts

Twin Dormer ManchesterBarn Conversion Oldham 

Double Dormer Loft Conversion in Lancashire

Two dormers added to a 3 bed semi to create a light, spacious bedroom/office.

Before and After

Step-by-step video series of this loft conversion.

Loft Office

The self employed owners of this 1930's three-bedroom semi-detached house needed a dedicated and comfortable home office for regular use.

The light, spacious bedroom/office exceeded their expectations for size and height.

Large Dormer Extension, Lancashire

Dormer loft bedroom/office

A two dormer design - one for stairwell, the other for bedroom is used to created a roomy, comfortable double room loft and a light, open and attractive stairs and landing area.

Loft Plans and Permissions

The client already had architectural plans but which failed to explain significant structural details such as an impossible dormer support structure. They had also missed opportunities under Permitted Development rights. So we improved and agreed modified plans where the dormer frame was supported and the head height raised.

The plans of non loft conversion firms often lack understanding of loft structures and of the rules governing conversion. The tendency is towards missing essential structural detail and over caution with regard size.

Planning permission wasn't required as the dormers were within permissible volume limits, do not face the road and the roofline was maintained.

The modified plans showed building-up of the internal supporting (hall-way/landing internal) wall and a steel joist running between this and the chimney. The RSJ takes the weight of the sloping roof and dormer, which is transferred directly down to the ground through brickwork. YouTube video of this

Maximising Internal Height

Double Roof Dormer Extensions, Lancashire

Side and rear dormers

Like many clients, it was stressed to us the importance of maximising the internal head height. This makes a room felt comfortable and airy when used for long periods.

We gained six inches raising the flat roof to the ridgeline. Our experience and the accuracy of our teams allows us to calculate to the millimetre the eventual height. We built up to the ridgeline and then cut and mechanically fix the ridge tiles to the front of the roof. This gives the effect of a ridge, when the roof is actually flat.

A vapour permiable layer and green mineral felt were torched on. Green felt overlaps the front roof edge and ridge tiles (cut in-half lengthways) are fixed to these. The finished roofline appears identical to the adjoining roof.

Dormer Roof Shape, Lancashire

Shape of the dormer

Office or Bedroom

The client is delighted with the spacious office which is easily transformed to a double bedroom. Office features include multiple power sockets distributed around the walls, arrays of dimmable downlights and large window areas to maximise natural daylight.


Natural light floods in throughout the day from multiple sources. The dormer faces east, a stairwell window faces south and a Velux faces west.

Night lighting uses dimmable down lighters in three independent sets to create any mood. The sloping roof section has lights that swivel to point down.

Electric power

Loft Staircase Dormer, Lancashire

Kite wind loft staircase

Seven double sockets fixed low in the walls ensure convenient and safe power. At eye level, we installed a double socket and aerial for a wall mounted TV.

Heating and Ventilation

A modern radiator on the supporting wall is connected to the existing gas-fired combi-boiler with ample capacity to serve the loft.

Ventilation to keep the air freshis via the two dormer windows with latches, the Velux opening vent and staircase window with small opener. The always feels light and airy, from high summer where a breeze can pass through to winter, when ventillation is used minimally.

Storage Space

Knee-wall storade has a door half way along the wall.

Side Dormer Stairwell

The side (hip-end) dormer contains the loft stairs. This allowed the existing bedrooms to remain untouched. The stairwell gives a light and airy feel to the whole landing area.

The space-saving double kite-wind stairs fit over the existing stairs. Detailed measurements ensuired suffficient head height remained.

Individual steps are finished to add character and height.

Fire Regulations

Rear Dormer, Lancashire

Rear dormer

Floor and wall insulation provides thermal performance and fire containment. The owners opted to replace the doors throughout the house with fire doors (rather than install mains fed alarms in the main rooms) and we fitted these within the existing frames. The client selected the doors and handles to match internal decor. The new doors feel strong and have superior acoustic insulation too.


Refurbished Slate Roof

The original roof fell short of current Building Standards and needed a waterproof, breathable membrane installing. The membrane protects the structure and acts as a barrier if slate damage results in water ingress.

A new lead collar is installed on the chimneybreast (made on site) and chimney flashings are fitted to ensure watertight junctions around the chimney. The high quality refurbishment ensures a long, trouble-free life for the roof.

Felt Flat Roof

The rear dormer has a felt roof. Marine ply is fixed to tapered battons for the pitch needed for drainage. An ICOPAL vapour permeable bituminous layer is torched on, followed by an ICOPAL green mineral felt-capping layer.

House before conversion, Lancashire

House before conversion

Drip formers on the edges keep rainwater and away from the roof structure. Gutters and down-pipe channel rain water away.

The flat roof is guarantee for 25 years.

Hip End Dormer Roof

The entire roof was re-battened and slated.

Dormer Cheeks

This uses materials sympathetic to the original house and in keeping with the neighbourhood. We explored options for cheek coverings such as lead faced (which can look industrial), timber sided (out of keeping) and pebble dash (not as hardy as desired).

The client chose to slate as these help protect the 'kerb-appeal' and are highly durable.

Building control certified the loft for hight, structure and insulation standards in accordance with Building Regulations.

Cost of Conversion

The approximate cost of a trussed roof conversion is £28,000 + vat. For a competitive, free quotation call us today on: 0800 505 3414

See more about our dormer plan services Dormer Plans and Dormer Extensions for information and for more Loft Conversion Examples.

Boarshurst Lofts

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