Loft
conversions
in Bushey, WD23
Designers, Architects, Engineers & Builders Under One Roof.
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A Bushey loft depends on the shape of its roof, on whether the house falls inside one of the four conservation areas, and on Hertsmere's design guide, which holds firm views on dormers and hipped roofs.
Bushey's roofs vary street by street. In the old village most buildings are two storeys under gabled roofs of old red tile or slate; on Park Road each group of cottages has its own gabled roofline; west Bushey's Arts & Crafts houses carry part hipped and gabled tile roofs, and one on the local list has a box dormer to its attic; and the High Road cottages of Bushey Heath are almost all slated. Among the mid-century houses and bungalows of North Bushey the roof shape changes from house to house, so we look before assuming anything.
Semi-detached houses held 38.0% of Bushey North's households and 30.5% of Bushey Park's at the 2021 Census. On a semi, the shared wall and the matching roof next door shape a conversion as much as the space inside it.
Sources: ONS Census 2021 TS044 accommodation type via Nomis (NM_2062_1), 2022 wards for bushey
Class B, conservation areas and a Bushey loft
The householder rules deal with roof enlargements in Class B. Roof space can be enlarged by up to 50 cubic metres, or 40 where the house is in a terrace, measured on the enlarged roof space with any earlier additions counted. The new roof cannot go higher than the existing roof's highest point or project past the plane of any roof slope forming the front elevation onto a highway, and balconies are not allowed.
Conditions come with it: outside materials that look like the existing ones, the original eaves left in place, the edge of the enlargement held, so far as practicable, at least 0.2 metres up the slope from the eaves, and any side window obscure glazed, with no part that opens lower than 1.7 metres above the floor. A rooflight standing more than 0.15 metres proud of the slope falls outside Class C, the allowance for other roof alterations.
Class B is switched off entirely on article 2(3) land, and conservation areas are part of that land; Bushey has four. Inside any of them a dormer, a hip-to-gable or any other roof enlargement needs planning permission, and an Article 4 direction can go further: the one on the Reveley Almshouses withdraws alterations to the roof form.
Where a loft at Farm Way, the former Ministry of Defence housing, needs permission, Policy SADM31 names roof design and ridge and eaves heights among the things new work must complement, so the scheme is drawn to sit with the original roofs.
Sources: legislation.gov.uk: GPDO 2015 (SI 2015/596), Schedule 2 Part 1, development within the curtilage of a dwellinghouse (latest available revised); legislation.gov.uk: Town and Country Planning (General Permitted Development) (England) Order 2015 (SI 2015/596), article 2 (latest available revised); legislation.gov.uk: GPDO 2015 (SI 2015/596), Schedule 1 Part 1, Article 2(3) land (latest available revised); Hertsmere Borough Council: Site Allocations and Development Management Policies Plan (adopted November 2016); Hertsmere Borough Council (BEAMS Ltd): Bushey High Street Conservation Area Appraisal 2008, main report; Hertsmere Borough Council: Draft Planning and Design Guide SPD Part D (draft for DM use and public consultation, October 2016)
Hertsmere's rules for dormers and hipped roofs
Once an application is needed, Part E of the design guide applies. It refuses roof extensions as wide as the house that read as a large box, and it normally refuses turning the sloping hip at a house's side into a gable end, because that unbalances the house, the pair of semis or the terrace. Where the attached house already has such a conversion under permitted development, a matching one may be allowed to rebalance the pair.
Dormers, the guide says, should give the room its light rather than be the room. It wants them as small as possible, generally on the rear slope, taking no more than 60% of the roof face, no closer than 0.3 metres to the ridge or the eaves, and 0.5 metres or more in from the side or boundary walls. Two smaller dormers can be better than one large one, and big permitted development dormers nearby are no argument for another.
Front dormers are resisted unless they are a dominant or original feature of the street, side dormers normally are too, and so are crown roofs. Bricks, tiles and window frames must match the house; several rooflights on the front slope may need permission; solar panels are not permitted on conspicuous elevations inside a conservation area; and using a flat roof as a terrace needs permission.
In the conservation areas the appraisals record slate and old red tile coverings, and note where concrete tiles have already replaced earlier coverings on Falconer Road and Park Road. New roofing on a Bushey loft is matched to the original covering, not to the replacement.
Sources: Hertsmere Borough Council: Planning and Design Guide SPD; Hertsmere Borough Council: Planning and Design Guide Part E: Guidelines for Residential Extensions and Alterations (adopted 2006); Hertsmere Borough Council (BEAMS Ltd): Bushey High Street Conservation Area Appraisal 2008, main report; Hertsmere Borough Council (BEAMS Ltd): High Road Bushey Heath Conservation Area Appraisal, draft (April 2013)
Escape route, new floor and approval in a Bushey loft
Once a conversion creates a storey higher than 4.5m, fire safety becomes a whole-house question. Approved Document B wants every part of the route out of the building dealt with: fire-resisting doors and partitions, existing doors upgraded where necessary, and, where rooms are open plan, added partitions that enclose the route.
Old doors of historical or architectural worth, such as the panelled timber doors recorded in the High Street appraisal, are candidates for retention: the guidance asks for keeping and upgrading them to be looked into before replacement. Instead of enclosing an open-plan layout, a house can rely on sprinklers covering the open-plan rooms plus a fire-resisting door and partition that cut the ground storey off from the storeys over it.
Where the house had two storeys, its new floor must reach at least REI 30 for fire resistance, and smoke alarms are to run off the mains. Approval and sign-off come from Hertfordshire Building Control or, if you choose, by a privately run registered building control approver.
On a semi or a terrace, steels bearing into the party wall, or the wall built up to form a gable, mean notice to the neighbour: cutting into a party wall and making one taller are both among the government's examples of notifiable work.
Sources: GOV.UK (MHCLG): Approved Document B (fire safety) volume 1: Dwellings, 2019 edition incorporating 2020, 2022, 2025 and 2026 amendments and forthcoming 2029 changes; Hertsmere Borough Council (BEAMS Ltd): Bushey High Street Conservation Area Appraisal 2008, main report; Hertsmere Borough Council: Hertfordshire Building Control Limited; GOV.UK: Building regulations approval (printable guide); GOV.UK: Party walls and building work (printable guide)
Converting a Bushey loft
Our London team takes on loft conversions across Bushey and Bushey Heath, with in-house architects, designers and structural engineers working beside Hampstead Chartered Surveyors & Building Consultancy. When the loft needs planning permission, Hertsmere Borough Council decides the application under its adopted Local Plan; for the building regulations we use Hertfordshire Building Control unless you prefer a private registered approver.
Our first measurement is the head height over the line of the new stair: in a Bushey semi it is the stair position, more than the floor area, that usually decides whether the loft works.
The roof is opened in sections under a scaffold and temporary cover, the new floor and steels go in before the old ceiling joists are cut, and the stair is formed last so the landing below stays in use.
Outside Bushey, and in London rather than Hertfordshire: Project example: Belsize Park, NW3. That project of ours included a loft conversion, sympathetic to the house, on a Victorian townhouse of five storeys, with its basement and rear extension alongside, as its case study describes.
Sources: Hertsmere Borough Council: Local Plan 2012-2027; Hertsmere Borough Council: Hertfordshire Building Control Limited; GOV.UK: Building regulations approval (printable guide); Hampstead Renovations: Belsize Park Gardens, NW3 case study
Loft Conversions in Bushey: Questions
Can I convert my Bushey loft under permitted development inside one of Bushey's conservation areas?
No. Conservation areas form part of article 2(3) land, and houses there fall outside Class B altogether, which is why a dormer or other roof enlargement in any of Bushey's four conservation areas needs planning permission. Outside them, a rear dormer within the Class B volume and design limits can be permitted development, unless an Article 4 direction has removed the right.
What fire safety work does a loft conversion in a Bushey house need?
If the conversion takes a storey above 4.5m, every part of the way out to the ground floor is dealt with: fire-resisting partitions and doors, with older doors brought up to standard where necessary, or else an alternative relying on sprinkler protection in open-plan rooms. In a house that had two storeys the new floor needs REI 30 fire resistance, alarms for smoke must be mains powered, and doors of historic merit are considered for keeping and upgrading before anyone replaces them.
Does a Bushey loft conversion need a party wall notice?
Usually yes, for a semi or a terrace. Seating steel bearings in an existing party wall, or building that wall up for a gable, needs notice to the neighbour, while plastering it or adding sockets does not. A detached house often needs no notice unless the work comes to the boundary.
Who signs off building regulations for a loft conversion in Bushey?
Either Hertfordshire Building Control or, at your choice, a registered approver from the private sector approves the conversion and signs it off. Lacking that approval, you would have no certificates of compliance to offer when the house is sold.
Will Hertsmere accept a hip-to-gable loft conversion on a Bushey semi?
Not normally as an application: the design guide says turning the sloping hip at a house's side into a gable end will normally be refused, because it unbalances the pair. Where the attached house already has one built under permitted development, a matching conversion may be allowed. Outside the conservation areas, Class B itself provides for hip-to-gable enlargements within its volume limits.
What do you look at first when visiting a Bushey loft?
The roof from the street and the garden, its shape and covering, and then inside: the head height where the stair would arrive, the rafters, purlins and any water tank, the chimney stacks, and the party wall if the house is attached. Back at the studio we look the road up on the conservation area map and in the council's list of Article 4 directions.
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