Services / Basement conversions
Basement conversions
Drawings for converting a cellar or digging a new basement, coordinated with the structural design and waterproofing from the outset.
- FreeInitial consultationA conversation about your project, and a first view of what's possible, before any fee is agreed.
- FixedFee for each stageEvery stage is priced in writing before it starts. No hourly billing.
- 3DSee the design firstYour design is shown in 3D before it's submitted, while changes are still easy.
- FreeResubmissionIf planning is refused, we revise and resubmit at no extra design fee. Conditions
What we draw
Cellar conversion
Turning an existing cellar into habitable space, often with lowering and waterproofing.
New basement
Excavating under the house or garden, which usually needs planning permission and a basement impact assessment in many boroughs.
Building regulations drawings
What's included
Construction drawings and specification for building control approval and for builders to price from.
- Building regulations plans, sections and specification
- Fire, insulation, ventilation and drainage notes
- Coordinated with the structural design
- Submitted to building control on your behalf
Before you start
What we need, and what sits outside our fee
- From you: the property address, a few photos, and any existing drawings, planning approvals or surveys you have. We arrange the measured survey with you.
- Not in our fee: council planning and building control fees, and specialist reports a council asks for, such as a tree survey or flood risk assessment, unless your fee proposal lists them.
- Your fee proposal sets out exactly what is included for your project before any work starts.
- Want it built too? Green Code Developers, the group's construction company, can build it under a separate contract, with one project lead throughout. How design and build works.
Timescales
How long it takes
We give you a timetable for our drawings in your fee proposal. Council and building control timings are the statutory or target periods and start once an application is validated.
- Planning decision
- Target of 8 weeks after validation
- Building regulations full plans
- 5 weeks, or up to 2 months if you agree
- Party wall notices
- 1 month for excavation near a neighbour, 2 months for party wall work
Projects
Basement conversions we have designed
Common questions
Does a basement need planning permission?
Converting an existing cellar often doesn't. Digging a new basement, or adding lightwells, usually does, and many London boroughs ask for a basement impact assessment.
Will I need a party wall agreement?
Usually, yes, because basement work is close to neighbouring foundations. We can serve the notices.
How long does the approval process take?
Planning applications have a target of eight weeks after validation, and party wall notices need at least one month for excavation near a neighbour, or two months for work to a party wall. We start both as early as the design allows.
Other services
- Free planning check
- House extensions
- Loft conversions
- Upward extensions
- Renovations and internal alterations
- Planning permission
- Lawful development certificates
- Pre-application advice
- Building regulations drawings
- Building control applications
- Structural calculations
- Structural surveys and letters of comfort
- Flat conversions
- Lease plans and licence to alter
- Change of use
- New builds
- Interior design
- 3D visualisation
- Energy and retrofit
- Energy Performance Certificates (EPC)
- Accessible home adaptations
- Commercial fit-outs and shopfronts
- Design consultations
- Party wall surveys
- Build over agreements and drainage
- Planning reports and statements
- Amendments, conditions and regularisation
- Planning appeals
- Conservation areas and listed buildings
- Community Infrastructure Levy (CIL)
- HMO planning and licensing
- Feasibility and site checks
- Measured surveys
- Building surveys
- Drawing reviews and second opinions
- Location and block plans
- Tender and construction support
- Principal designer (CDM and building regulations)
- Cost management
- Project management
- Contract administration
- Design and build
- Turnkey projects
- Landscape design
Where we work
Basement conversions across London
Local planning points for the boroughs closest to our Cricklewood studio: Ealing, Harrow, Brent, Hillingdon, Hounslow, Haringey, Enfield, Barnet, Camden, Westminster, Hammersmith and Fulham, Kensington and Chelsea. See all 33 boroughs.