Whether you’re converting a large home into flats or carrying out a commercial-to-residential conversion, you’ll need an experienced architect or designer. Flat conversions are complex projects that require careful consideration of planning policy, space standards, natural light, fire safety, and building regulations. At Detailed Planning, we have delivered successful flat conversions across multiple London boroughs. Our team combines strong design principles with an in-depth understanding of local planning policies, giving you the best chance of approval and a high-quality, compliant design.

We provide competitive, fixed fees per stage, so you always know what to expect. For flat conversions, we typically recommend a five-stage process, starting with a concepts and feasibility phase.

• Initial investment: £1,000–£2,000
  This first stage allows us to assess the site’s potential, review the likelihood of obtaining planning permission, and prepare initial concept layouts showing how many flats could be achieved. From there, we can move into pre-application advice, detailed design, and a full planning submission, before progressing into technical and construction phases.

Absolutely. We regularly work with property developers in London to maximise site value by converting existing buildings into multiple flats. Whether it’s a large family home or a disused office building, our role is to:

• Identify the maximum development potential.

• Design layouts that meet London Plan space standards and Building Regulations.

• Balance planning requirements with commercial viability to ensure strong rental yield or resale value.

Timelines vary depending on the borough and project type. As a guide:

• Pre-application advice: usually takes around 8 weeks.

• Full planning applications: typically 8–10 weeks once validated.

Many flat conversions also require specialist reports, such as daylight and sunlight assessments, transport statements, or fire safety strategies, which can extend the process. Where objections or complex planning issues arise, applications may take longer. Our team manages this process for you to minimise delays.

Yes. Once planning permission is granted, we lead the technical phase of your flat conversion, ensuring your project is fully compliant and ready to build. Our services include:

• Preparing building regulation drawings.

• Coordinating with structural engineers, fire consultants, and energy assessors.

• Assisting with planning condition discharges.

• Advising on building warranty providers and building control approvals.

During construction, we can provide ongoing project assistance, including fortnightly site visits, progress reports, and guidance with contractor communication. If required, we can also recommend a quantity surveyor to provide financial monitoring and payment certification.