Loft conversion drawings, Durham & the North East
Extra bedroom, home office or hangout for the kids. We design rooflight, dormer and hip-to-gable loft conversions and prepare the plans, building regulations pack and structural calculations for the build, from our Durham office for homeowners across the North East and remotely nationwide.
More space without extending your footprint
A loft conversion adds living space and value while the house stays the same size on the ground. Most are permitted development, so there is often no planning application to wait for, but every habitable loft needs building regulations approval and a structural design: the existing ceiling joists are almost never strong enough to carry a floor, and adding a storey changes the fire-escape strategy for the whole house. We work through the layout, headroom, stair and windows with you, then prepare the technical and structural detail in the same office. As a rough 2026 guide, a rooflight conversion of around 4m by 5m costs £27,000 to £33,000 to build outside London and a dormer £40,000 to £48,000; a detailed specification is what turns those ranges into a firm builder's price.
- Existing plans, roof plan and sections from our measured survey of the roof space
- Proposed loft plans, sections and elevations showing headroom, the new stair, rooflights or dormer and any en-suite
- Planning drawings and application as your agent where needed, or a Certificate of Lawful Development
- Building regulations drawings and specification covering floor, stair, fire safety, insulation, ventilation and windows
- Structural calculations and drawings for the new floor, steel beams, dormer and roof alterations
- Rooflight (Velux) conversions with no change to the roof shape
- Rear and side dormer conversions
- Hip-to-gable conversions, alone or with a rear dormer
- Bungalow loft conversions and whole-house remodels
- Lofts designed alongside an extension or garage conversion
From roof-space survey to a builder-ready pack
- Site visit and measured survey. We measure the roof space, ridge height, purlins, ceiling joists and the landing below, and photograph everything the design depends on.
- Existing and proposed drawings. Scaled drawings of the house as it stands, then the loft layout, stair position and roof form, refined with you in person or by video call. Survey to agreed design typically takes one to three weeks.
- Planning application, if required. We check the added volume and roof form against permitted development. Where a full application is needed we prepare the drawings in two to three weeks and manage it as your agent; councils typically take around eight weeks to decide.
- Building regulations drawings and specification. Sections and details for the floor, stair, fire protection, insulation and rooflights or dormer, typically prepared within two to three weeks.
- Structural design. New floor joists or steel beams, trimmers around the stair, dormer framing and roof alterations, calculated by our in-house engineers in parallel with the drawings.
- Optional stages. Building control application, tendering to a shortlist of contractors and site support through to the completion certificate.
Every stage is fixed in writing before it starts and paid at the start of that stage. See the full nine-stage process and timescales.
How our fees work
Every stage is a fixed fee, agreed in writing before it starts, and you only pay for the stages you use. The figure depends on the type of project, the size and type of your property and where it is: site visits outside our local postcode areas (NE, DH, DL, TS and SR) carry a travel charge, projects inside the M25 are priced higher, and listed buildings and conservation areas involve extra work. Council and building control fees are separate and paid directly to them.
- Site visit and measured survey
- Existing and proposed drawings
- Planning application, submitted as your agent, where required
- Building regulations drawings and specification
- Structural design and calculations
- Optional extras such as 3D visuals, party wall notices and site support
The instant quote tool prices every stage separately for your property in about two minutes, with no obligation. If you already have planning drawings, upload them and we send a fixed written proposal.
Planning permission and building regulations for lofts
- Added roof volume within 40m³ on a terraced house or 50m³ on a semi-detached or detached house, measured against the original roof
- No part higher than the existing ridge, and dormers set back at least 20cm from the original eaves where practical
- Rooflights projecting no more than 150mm above the roof slope
- Side-facing windows obscure-glazed and, if they open, at least 1.7m above the floor
- Any dormer or roof extension on the principal elevation fronting a highway
- Conversions that exceed the 40m³ or 50m³ volume allowance
- Homes in conservation areas and other designated land, and any flat or maisonette
- Balconies, verandas or raised platforms formed as part of the conversion
Building regulations apply to every habitable loft regardless of planning: a compliant stair under Approved Document K, a protected escape route with FD30 fire doors and interlinked mains smoke alarms under Approved Document B, a new floor structure and insulation to current thermal standards. We prepare the drawings and calculations and act as your agent with the council or registered building control approver. This is a general guide to the rules in England; we confirm the position for your property before any drawings are produced.
Loft drawings from a completed project
Our example packs include the planning and building regulations drawings for a whole-house extension with dormer loft and internal remodel, anonymised and shown at reduced resolution. Browse the example project packs to see what you will receive.
Frequently asked
Do loft conversions need planning permission?
Usually not. A loft conversion is permitted development if the added roof volume stays within 40 cubic metres on a terraced house or 50 cubic metres on a semi-detached or detached house, nothing rises above the existing ridge, and any dormer is on the rear or side. Front dormers, conservation areas, flats and homes with permitted development rights removed need a full application. We confirm before you commit.
How much do loft conversion drawings cost?
Our fees are fixed per stage: design drawings, the building regulations pack and structural design are each priced separately and agreed in writing before they start. The figure depends on the type of conversion (rooflight, dormer or hip-to-gable), your property and its location. The instant quote tool gives the exact figure for your home.
How long do loft conversion drawings take?
Survey to an agreed proposed design typically takes one to three weeks, and the building regulations drawings and structural design are typically prepared within two to three weeks, usually in parallel. Because most lofts are permitted development there is often no eight-week planning wait.
What is the minimum stair width for a loft conversion?
There is no single fixed minimum width in England, but the staircase must meet Approved Document K: 2m of headroom, reducing to 1.8m at the lowest edge under a sloping ceiling, a pitch no steeper than 42 degrees, risers of 150mm to 220mm, goings of 220mm to 300mm and a handrail 900mm to 1000mm high. Where a conventional stair will not fit, an alternating-tread or spiral stair may be acceptable for a single room. We design the stair to comply within the space you have.
What do the building regulations require for a loft conversion?
Every habitable loft needs building regulations approval even when no planning permission is required. The application must show a new floor structure strong enough for a habitable room, a compliant staircase, a protected escape route with fire doors and interlinked mains smoke alarms on every storey, and roof and wall insulation to current thermal standards. Our pack and calculations cover every element.
Can my existing ceiling joists take a loft floor?
Almost never. Ceiling joists are sized to hold up a ceiling, not people and furniture, so a structural engineer calculates new floor joists or steel beams to carry the loads to the walls. Our engineers do this in-house alongside the drawings, so the floor, any dormer and the altered roof are designed together.
Guides and related projects
Ready to get started?
Tell us about your project and we'll talk you through the right stages, the likely route and what to expect.