Feasibility, planning strategy and coordinated applications for residential, commercial and mixed-use conversions.
Article reviewed 1 August 2026
Initial consultationFree
Measured surveyStarting from £395
Planning drawingsStarting from £1,400
Planning application submission£100
Building Regulations packageFrom £1,295
Rear extension packagePlanning and Building Regulation drawings from £1,750
Loft conversion packagePlanning and Building Regulation drawings from £1,950
Commercial planningQuote on request
Fees are starting prices and depend on property size, complexity, location and scope. Statutory application charges, Planning Portal charges, Building Control fees, specialist consultants and VAT where applicable are additional.
Confirm the lawful existing use first
A change-of-use strategy begins with evidence. We review the planning history, lawful use, any conditions, occupancy pattern and available records. Marketing descriptions or business rates alone may not prove the planning use. Where status is uncertain, a lawful development certificate or further evidence may be appropriate before redesigning the property.
Full planning permission, prior approval or permitted development
Some changes within the same use class do not amount to development. Other changes benefit from permitted development rights but require prior approval, while materially different uses need full planning permission. Article 4 Directions, listed status, conditions and local policies can remove or limit otherwise available routes. We compare the options rather than assuming the quickest route is available.
Use Classes E, C1, C3, C4 and sui generis
Typical instructions include commercial-to-residential proposals, subdivision into flats, homes to small HMOs, hotels or short-stay accommodation, cafés and restaurants, takeaways, medical or educational uses, offices, retail and mixed-use buildings. Each has different policy and operational implications. We define the precise existing and proposed use before preparing the application.
Residential quality and policy tests
Conversions to housing may need to demonstrate adequate internal space, daylight, outlook, privacy, access, cycle and refuse storage, noise protection, ventilation, overheating control and—in some circumstances—affordable housing or other policy requirements. A technically possible floor plan is not necessarily a planning-compliant one.
Commercial operation and neighbour impact
Opening hours, deliveries, customer movements, extraction, plant, waste, lighting, signage, security and noise can determine whether a commercial change of use is acceptable. We build these operational matters into the design and supporting statements, then coordinate acoustic, odour, transport or air-quality consultants when necessary.
From consent to technical delivery
After planning, a conversion may require Building Regulations design, fire strategy, structural alterations, acoustic separation, accessibility upgrades, energy improvements, licensing and landlord or freeholder consent. We can coordinate these workstreams, while making clear that planning approval does not replace separate statutory regimes.
How Horizon Architecture manages the process
- Free initial discussion and scope definition.
- Review of the address, planning history and relevant consent route.
- Measured survey or review of reliable existing information.
- Design development and coordination of the required application documents.
- Submission, validation checks and active monitoring with the council or Building Control.
- Prompt responses to reasonable queries and proportionate amendments where appropriate.
- Coordination with structural engineers, heritage consultants, acoustic specialists, arboriculturalists, drainage, transport, fire, energy or MEP advisers where the project requires them.
Our starting fees
Initial consultation is free. Measured surveys start from £395; planning drawings from £1,400; application submission is £100; Building Regulations packages start from £1,295; combined rear-extension planning and Building Regulation drawings start from £1,750; combined loft-conversion packages start from £1,950. Commercial planning is quoted to suit the project. Statutory and third-party costs are additional.
Frequently asked questions
Can a shop become a flat without full planning permission?
Sometimes a prior-approval route may apply, but eligibility, floorspace, location, conditions, Article 4 controls and residential-quality tests must be checked.
Do I need planning permission to change one commercial use to another?
Not always. Some uses fall within Class E, but external works, conditions, operational impacts or a sui generis use may still require permission.
Can you assess a property before I buy it?
Yes. A pre-purchase planning feasibility review can identify the likely use, policy risks and information gaps before commitment.
Will I need an acoustic report?
Possibly, particularly for residential conversion near commercial activity, transport noise, plant, entertainment or late-opening uses.
Do you deal with licensing?
Licensing is separate from planning. We can coordinate the architectural information and liaise with a licensing specialist where required.
Get a free project quotation
Send us the property address, photographs and a short description of the work. We will confirm the likely stages, information required and an appropriate fee proposal.
Get a free quoteRelated services
Planning applications · Building Regulations · House extensions · Loft conversions · Conservation areas · Planning refusals · Areas across London
Guidance basis
Article updated 1 August 2026. Current national planning statistics and fees are checked against MHCLG official statistics and Planning Portal guidance. Project-specific legal and technical requirements must be verified for the address and scope.
